EOS

Groundwater is one of Earth’s most important natural resources—it’s the world’s biggest source of accessible freshwater, and in dry parts of the world, it supplies most of the water humans consume. In Australia, for example, where more than 70% of the landmass is semiarid or arid, groundwater is the only reliable source of freshwater, supplemented by limited seasonal or episodic rainfall.

Estimates of regional and global groundwater recharge exist, but they typically come with large uncertainties because recharge is generally measured indirectly: Scientists extrapolate from measurements of water table fluctuations or streamflow loss, or they simply estimate recharge as a percentage of rainfall. Moreover, the relationships between individual rainfall events and groundwater recharge are rarely examined because existing methodologies have focused on gathering data to estimate recharge volumes on monthly or annual timescales.

Groundwater is replenished, or recharged, when water—usually from precipitation—percolates into bedrock from the surface, raising the water table. However, scientists have relatively little knowledge of when this replenishment occurs and how much precipitation is needed to refill underground reservoirs known as aquifers.

The lack of understanding of when and how water goes from the surface to a reservoir makes it difficult to predict how groundwater recharge will change as the climate changes.

The lack of understanding of when and how water goes from the surface to a reservoir makes it difficult to predict how groundwater recharge will change as the climate changes. This difficulty will be increasingly problematic as our knowledge of past rainfall patterns becomes obsolete and no longer helps us to allocate water sustainably.

To reveal the relationship between rainfall and groundwater recharge, we can use a metric referred to as the rainfall recharge threshold. This threshold is the amount of rainfall that is needed for groundwater recharge to occur at a given location and time. We can determine this value if we can observe groundwater being recharged and we have weather data from prior to the recharge event so we know how much precipitation fell.

Measuring this threshold at different times and places allows us to assess how much rainfall is needed to recharge groundwater and how the amount varies seasonally and over time, how often that amount falls, and what weather patterns and climate processes make recharge events more likely.

Addressing these unknowns, in turn, helps us understand recharge processes in more detail and improves our ability to manage valuable groundwater resources sustainably.

Watching Groundwater Flow Fig. 1. This map of Australia, with state and territory borders demarcated, shows annual average rainfall across the continent, as well as the locations of current National Groundwater Recharge Observing System (NGROS) sites. Site 1, Capricorn Caves; site 2, Daylight Cave; site 3, Wellington Phosphate Mine; site 4, Wombeyan Caves; site 5, Yarrangobilly; site 6, Walhalla Mine; site 7, Derby mine tunnel; site 8, Marakoopa Cave; site 9, Ajax South Adit; site 10, Durham Lead Adit; site 11, Berringa Adit; site 12, Stawell Mine; site 13, Byaduk Lava Cave; site 14, Naracoorte Caves; site 15, Tantanoola Caves; site 16, Old Sleep’s Hill Tunnel; site 17, Montacute Mine; site 18, Burra Mine Adit; site 19, Elliston; site 20, Yanchep. Click image for larger version.

Our team has implemented an innovative approach to quantify rainfall recharge thresholds throughout Australia [Baker et al., 2024]. The approach involves directly detecting potential groundwater recharge using a network of automated hydrological loggers deployed as close to the water table as possible (so measurements are as representative of true recharge as possible) in underground tunnels, mines, and caves (Figure 1).

Since 2022, we have placed loggers at 20 sites, such as an abandoned train tunnel in Precambrian to Cambrian sandstone (at Old Sleep’s Hill Tunnel in South Australia; Figure 1, site 16), a heritage gold mine in Devonian metasedimentary rock (at Walhalla Mine in eastern Victoria; site 6), and a lava cave in Quaternary basalt (at Byaduk Lava Cave in western Victoria; site 13). These sensors make up Australia’s National Groundwater Recharge Observing System (NGROS), the first dedicated network for observing event-scale groundwater recharge across different geologic and surface environments, as well as across a wide range of Australian hydroclimates.

The hydrological loggers we use detect the impacts of falling water droplets that hit them, meaning they must be placed in open underground spaces, rather than buried in soil. They were originally designed to count drips falling from cave stalactites, but they count drips falling from the roof of any underground space just as well.

Sharp increases in drip rates allow us to identify the precise timing of recharge events.

In the time series datasets from replicate loggers at each site, sharp increases in drip rates allow us to identify the precise timing (and location, season, and climatic conditions) of recharge events—similar to how spikes in streamflow help identify flood episodes in river hydrographs. With this information, we can tie recharge to specific precipitation events, and by combining it with daily rainfall data, we can quantify rainfall recharge thresholds and their variability with geography and through time.

Confidently linking rainfall and recharge events also requires that water percolate from the surface toward the water table fast enough that the rainfall response is preserved. For this reason, loggers are placed where water flows predominantly—and rapidly—through features such as rock fractures rather than more slowly through tighter pore spaces. Data from NGROS therefore also shed light on recharge processes in fractured rock terrains, which have been relatively less researched than those in porous rocks and sediments.

We deliberately sited some NGROS sensors to be close to Australia’s new network of critical zone observatories to complement infrastructure that is recording stocks and flows of carbon, water, and mass from the plant canopy to the groundwater. We also chose cave sites where we plan to reconstruct records of past recharge by analyzing cave stalagmites. Our improved understanding of the climate conditions necessary for recharge to occur today will help us interpret stalagmite oxygen isotope compositions at these sites as a proxy for past periods of groundwater recharge and drought.

Heavy Rains Required

At NGROS sites where at least 1 year’s worth of data have been collected, we’ve observed that 10–20 millimeters of rainfall over 48 hours are typically needed to initiate recharge in fractured rock aquifers [Priestley et al., 2025].

We have seen a clear relationship across the sites between lower numbers of recharge events and higher rainfall thresholds.

Such rainfall events are infrequent in Australia. Between five and 18 occurred at each site in the first year the loggers were observing, with the fewest observed at Daylight Cave in eastern New South Wales (site 2) and the most at Capricorn Caves in central Queensland (site 1). These rainfall recharge events generally occurred when specific weather conditions manifested, such as the co-occurrence of cyclones or fronts with thunderstorms.

Regardless of the frequency of recharge events, we have seen a clear relationship across the sites between lower numbers of recharge events and higher rainfall thresholds. This relationship also holds despite differences in soil, vegetation, geology, and depth to the loggers, suggesting that climate is a major control on rainfall thresholds.

Most of the rainfall recharge events (86%) occurred in wetter seasons, and during these times, rainfall recharge thresholds were lower than in drier seasons: The median wet season rainfall recharge threshold was 19.5 millimeters in 48 hours, compared with 30.4 millimeters per 48 hours in the dry season [Priestley et al., 2025].

Drip loggers in the NGROS network were placed, for example, on old mining infrastructure in a former gold mine in Walhalla (left) and under an inflow zone in a gold adit in Durham Lead, near Ballarat, Victoria (right). The loggers can measure a maximum rate of four drips per second and can last roughly 3 years using internal batteries. Credit: Wendy Timms

The seasonal control on recharge is likely related to the greater amount of rainfall required to saturate soils during dry season events, although this control may be modulated by site‐specific factors such as soil conditions, unsaturated zone thickness, and vegetation. For example, sites vegetated with native woodland might be expected to have a greater unsaturated zone water demand in hot summer conditions and therefore to require more rainfall to generate recharge than more sparsely vegetated sites [Baker et al., 2024]. We will investigate the influence of these factors further as we collect longer time series of data.

Our results have also produced some surprising findings. Although we expected that antecedent weather conditions would influence the amount of rainfall needed for recharge to occur, we have not yet seen a clear relationship between preceding rainfall amounts or the time since the last recharge event and observed rainfall recharge thresholds. Longer time series of data should help to clarify the role of antecedent conditions as well.

Guiding Groundwater Management

Findings from NGROS have important implications for water management in Australia. Government groundwater management strategies, such as in the states of New South Wales and South Australia, where groundwater is the largest source of freshwater, rely on scientific data to support sustainable extraction and to protect groundwater-dependent ecosystems.

Our observations provide useful guidance for regulators setting extraction limits in the near term; they’re also useful to groundwater managers planning for changing future demands.

Our observations showing that only a handful of recharge events occur annually and that recharge requires a relatively high rainfall amount can, for example, provide useful guidance for regulators setting extraction limits in the near term. They’re also useful to groundwater managers planning for changing future demands resulting from changes in population, growth in agriculture and in mining industries supporting the green energy transition, and climate change.

Climate change is predicted to cause greater climatic variability across Australia, parts of which are already experiencing both wet and dry extremes. However, it is not yet clear to what extent changes in the climatic conditions that affect rainfall recharge thresholds will influence soil infiltration and overall groundwater recharge. The NGROS network is designed to investigate this question.

As a growing number of towns and even large cities (e.g., Perth, Western Australia [Broderick and McFarlane, 2022]) are forced to consider alternatives to shrinking groundwater resources, detailed information about regional and local recharge could help improve decisionmaking and give water managers more time to consider options.

NGROS findings also highlight that models used to inform groundwater management should factor in how recharge relates not only to rainfall amounts but also to the season and manner in which the rain is delivered (e.g., in long-duration, high-magnitude events versus intense bursts or prolonged sprinkles). This treatment conflicts with current practice, which typically quantifies recharge as a percentage, or some function, of annual rainfall. By instead considering the links between rainfall patterns and recharge, we can better identify how climate-induced changes in rainfall may impact future recharge.

Expanding the Network

NGROS data are already providing a more detailed understanding of rainfall recharge thresholds in Australia, helping refine recharge rate estimates by showing which rainfall event characteristics lead to recharge. Longer NGROS network time series, combined with other data such as groundwater level observations, will further help quantify recharge processes and reveal variability and trends over time and across the continent.

The concept of an underground groundwater recharge observing network could be applied more widely.

Beyond the 20 sites currently instrumented, the concept of an underground groundwater recharge observing network could be applied more widely, and we are continuously looking to expand the network within Australia and beyond.

Most recently, we installed loggers in sinkholes (vertical dissolution caves) on the Eyre Peninsula in South Australia, an arid region where groundwater levels have been falling. We have also commenced collaborations with colleagues in Africa, Europe, and North America, sharing our experience and know-how in setting up logger networks.

If groundwater observing networks are expanded to other parts of the world, researchers could compare recharge thresholds and processes across a wider range of climates, weather patterns, geologies, and environments to gain a more comprehensive view of when and how precipitation leads to recharge. Such knowledge would support sustainable management of vital groundwater resources not only in Australia but around the world.

Acknowledgments

Maria de Lourdes Melo Zurita (University of New South Wales, Sydney) also contributed to the underlying research project and provided feedback for this article.

References

Baker, A., et al. (2024), An underground drip water monitoring network to characterize rainfall recharge of groundwater at different geologies, environments, and climates across Australia, Geosci. Instrum. Methods Data Syst., 13(1), 117–129, https://doi.org/10.5194/gi-13-117-2024.

Broderick, K., and D. McFarlane (2022), Water resources planning in a drying climate in the south-west of Western Australia, Australas. J. Water Resour., 26(1), 72–83, https://doi.org/10.1080/13241583.2022.2078470.

Priestley, S. C., et al. (2025), Groundwater recharge of fractured rock aquifers in SE Australia is episodic and controlled by season and rainfall amount, Geophys. Res. Lett., 52(5), e2024GL113503, https://doi.org/10.1029/2024GL113503.

Author Information

Stacey Priestley (stacey.priestley@csiro.au), Commonwealth Scientific and Industrial Research Organisation, Adelaide, SA, Australia; Andy Baker (a.baker@unsw.edu.au), University of New South Wales, Sydney, Australia; Margaret Shanafield, Flinders University, SA, Adelaide, Australia; Wendy Timms, Deakin University, Geelong Waurn Ponds, Vic, Australia; and Martin Andersen, University of New South Wales, Sydney, Australia

Citation: Priestley, S., A. Baker, M. Shanafield, W. Timms, and M. Andersen (2025), When does rainfall become recharge?, Eos, 106, https://doi.org/10.1029/2025EO250452. Published on 4 December 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Source: Community Science

The Xwulqw'selu Sta'lo' (Koksilah River) is a culturally important river to the Cowichan Tribes, located on traditional Quw'utsun land on Vancouver Island, British Columbia. The land, which was never ceded to Canada, is part of a watershed that faces challenges including decreasing salmon populations, low river flow, flooding, and land use changes.

Gleeson et al. are working with the Cowichan Tribes and the provincial government to collaborate on the first water sustainability plan in British Columbia. About halfway through their 5-year project, the researchers are sharing how their work is guided by five “woven statements,” representing their intentions and values. These statements include a commitment to uphold Quw'utsun rights and laws, an intention that community-based monitoring and modeling will inform water and land decisions about the river, and a commitment by researchers to share their practices and outcomes. Just like the horizontal wefts and vertical warps in traditional Coast Salish weaving practices, these statements overlap and connect with their research goals, projects, and partnerships.

The research project has three goals: to improve understanding of current and future low flows in the Xwulqw'selu Sta'lo' through community science; to promote community engagement with water science, water governance, and Indigenous Knowledge; and to examine how this community science work can be useful to shared watershed management.

To accomplish these goals, the researchers use traditional scientific practices deeply grounded in the river itself. The community science project includes hydrological monitoring, modeling of low river flows, and quantification of groundwater flows into the river. In 2024, 44 volunteers participated in the community science project.

The 5-year project is part of the larger Xwulqw'selu Connections program, which supports a shift toward water cogovernance between the Cowichan Tribes and the provincial government through the Xwulqw'selu Water Sustainability Plan. The program could inform other community science collaborations between governments and Indigenous peoples, the authors say. (Community Science, https://doi.org/10.1029/2024CSJ000120, 2025)

—Madeline Reinsel, Science Writer

Citation: Reinsel, M. (2025), Watershed sustainability project centers place-based research, Eos, 106, https://doi.org/10.1029/2025EO250439. Published on 4 December 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Journal of Geophysical Research: Solid Earth

Reconstructing the direction and rate of motion of tectonic plates is essential for understanding deformation within and between plates and for evaluating the geodynamical drivers of plate tectonics. One debate concerns the relative importance of flow in the asthenosphere versus processes at plate boundaries in controlling the motion of tectonic plates.

Wilson and DeMets [2025] present the most detailed reconstruction of changes in motion of the Nazca Plate to date. Remarkably, their results show periods of constant motion separated by geologically short periods of rapid acceleration or deceleration. These changes coincide with changes in the dip of the Nazca plate where it subducts beneath South America, with decelerations occurring when multiple regions of the slab shallowed to anomalously low dips (“flat slab subduction”), and accelerations occurring when the slab deepened to normal dips.  These results imply that changes in the forces acting between plates are an important control on plate motion.

Citation: Wilson, D. S., & DeMets, C. (2025). Changes in motion of the Nazca/Farallon plate over the last 34 million years: Implications for flat-slab subduction and the propagation of plate kinematic changes. Journal of Geophysical Research: Solid Earth, 130, e2025JB031933. https://doi.org/10.1029/2025JB031933

—Donna Shillington, Associate Editor, JGR: Solid Earth

Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

body {background-color: #D2D1D5;} Research & Developments is a blog for brief updates that provide context for the flurry of news regarding law and policy changes that impact science and scientists today.

At the White House today, President Donald Trump announced his administration would “reset” vehicle fuel economy standards. Trump said the administration plans to revoke tightened standards, also known as Corporate Average Fuel Economy (CAFE) standards, set by President Joe Biden in 2024.

“We’re bringing back the car industry that was stolen from us.”

“We are officially terminating Joe Biden’s ridiculously burdensome—horrible, actually—CAFE standards that imposed expensive restrictions and all sorts of problems, all sorts of problems, to automakers,” Trump said. “We’re bringing back the car industry that was stolen from us.”

Automobile executives from Ford, General Motors (GM), and Stellantis joined federal officials, including Department of Transportation Secretary Sean Duffy, at the announcement. The administration said, without providing evidence during today’s announcement, that the current CAFE standards have increased vehicle prices and estimated that changing those standards would save American families $109 billion in total.

Vehicle fuel efficiency standards, which set the average gas mileage that vehicles must achieve, have been in place since 1975. The standards were most recently tightened in June 2024 by the Biden administration, and required automakers to ensure vehicles achieved an average fuel efficiency of about 50.4 miles per gallon by model year 2031. The Biden administration estimated that the rule would lower fuel costs by $23 billion and prevent the emission of more than 710 million metric tons of carbon dioxide by 2050. 

Fuel economy standards have significantly reduced greenhouse gas emissions from vehicles, which are one of the largest sources of carbon emissions in the United States. According to one estimate, fuel economy improvements spurred by the standards have avoided 14 billion tons of greenhouse gas emissions since 1975. 

However, Duffy said, the current standards are “completely unattainable” for automakers.

The announcement did not specify the degree to which the administration would lower the standards.

 
Related

•  Fact Sheet: President Donald J. Trump Announces the Reset of Corporate Average Fuel Economy (CAFE) Standards
•  Read about the 2024 standards: USDOT Finalizes New Fuel Economy Standards for Model Years 2027-2031
•  U.S. Fuel Economy and Greenhouse Gas Standards: What Have They Achieved and What Have We Learned?
•  Get Involved: AGU Science Policy Action Center
 

Weakening fuel economy rules for vehicles is the latest step in President Trump’s continued efforts to slow the adoption of electric vehicles and boost the fossil fuel industry. 

Trump’s One Big Beautiful Bill, the omnibus spending bill that became law in July, also eliminated fines for automakers that did not comply with fuel economy standards. The Environmental Protection Agency is also expected to weaken limits of greenhouse gas emissions from vehicles by finalizing the repeal of the 2009 Endangerment Finding, which underpins important federal climate regulations, early next year. 

Policy advocates said weakening the standards would slow the transition to electric vehicles and make the U.S. vehicle market less competitive. “While Trump tells G.M., Ford and others that they needn’t make gas-saving cars, China is telling its carmakers to take advantage of the lack of U.S. competition and accelerate their efforts to grab the world’s burgeoning clean car market,” Dan Becker, director of the Safe Climate Transport Campaign at the Center for Biological Diversity, told The New York Times. 

However, automakers supported the proposal. “As America’s largest auto producer, we appreciate President Trump’s leadership in aligning fuel economy standards with market realities,” Jim Farley, Ford’s CEO, told Fox News.

“Today is a victory of common sense and affordability,” Farley, who attended the announcement, said. 

The Transportation Department will solicit public comments about the rule and is expected to finalize it next year.

—Grace van Deelen (@gvd.bsky.social), Staff Writer

These updates are made possible through information from the scientific community. Do you have a story about how changes in law or policy are affecting scientists or research? Send us a tip at eos@agu.org. Text © 2025. AGU. CC BY-NC-ND 3.0
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As a child in Algeria in the late 1990s, Walid Ouaret remembers going to the mosque when droughts turned severe. There, he and his family would join their neighbors in a communal prayer for rain called the Salat al-Istisqāʼ. It was no informal event: The ceremony had been announced by the government.

“I was not a farmer, but I was feeling for other people from my own community,” remembered Ouaret, who’s now a Ph.D. candidate at the University of Maryland studying the intersections of climate and agriculture.

As he explored ways to improve the climate models he was using to understand the ramifications of climate change, Ouaret remembered the rain prayers. Rainfall patterns are changing globally due to climate change, but data from places like Algeria can be sparse. The Salat al-Istisqāʼ, on the other hand, is practiced across the Muslim world, which spans northern Africa, the Middle East, and Central Asia.

“I was trying to find a proxy, something that would tell me when food production was impacted or soil moisture was impacted at this regional [scale].”

“I was trying to find a proxy, something that would tell me when food production was impacted or soil moisture was impacted at this regional [scale],” he said. The call for rain prayers, he realized, could be a key data point revealing when droughts had become sufficiently severe to warrant state-led interventions.

In most instances, the ceremony is widely advertised, giving Ouaret a simple way of tracking its prevalence over time.

A New Kind of Climate Data

For research that will be presented on 18 December at AGU’s Annual Meeting 2025, Ouaret and his coauthors combed through mass media, including newspapers and websites, from Algeria, Morocco, and Tunisia from 2000 to 2024, looking for announcements of Salat al-Istisqāʼ. Then, they calculated how likely the calls for rain prayers were to correspond to drought conditions, as measured by the Standardized Precipitation Evapotranspiration Index.

Ouaret found a strong correlation between Salat al-Istisqāʼ notices and 6-month drought severity, which validated the announcement of rain prayers as a proxy for extreme weather. The environment wasn’t the only relevant influence on the calls to prayer, however. Ouaret said social unrest, as measured by conflict event data, was also associated with the announcement of rain prayers. That confluence is a sign, he said, that calls to prayer may also function as a governance tool for increasing social cohesion.

These kinds of data are valuable, as they illuminate areas of the planet with fewer reliable climate monitoring networks, said Jen Shaffer, an ecological anthropologist also at the University of Maryland, who wasn’t involved in the research.

“This sort of grassroots, bottom-up view is really valuable to get at areas where we don’t have weather stations.”

“People are getting signals of change going on in the environment that’s not easy to record with satellite data, or with all of our instruments,” Shaffer said. “This sort of grassroots, bottom-up view is really valuable to get at areas where we don’t have weather stations.”

The Maghreb and other regions of Africa are vulnerable to such lack of data, but agricultural communities around the world are beset by climate-induced challenges.

Rituals that ask for rain are common in cultures both past and present, from the kachina of the Pueblo cultures of the American Southwest to Catholic pro pluvia rogation ceremonies practiced in Spain to Days of Prayer for Rain in the State of Texas designated by the state’s governor in 2011. These practices offer both a historical record of drought and a potential input for climate models.

Adding cultural events to climate models, which are normally fed rigorously quantitative data, can be difficult, Shaffer noted. But Ouaret’s dataset benefits from the fact that a public, official announcement of rain prayers can be tied to specific dates and locations.

In the future, Ouaret believes his work could provide a potential early-warning system for drought vulnerability in specific communities, allowing more time to marshal aid to where it’s needed most. Data on the frequency of calls for rain prayers could also be a helpful tool for talking about climate change in affected communities, he said.

Communities “have been doing this in the past, but it was happening like once every 5 years. Now it’s happening every year,” Ouaret said. Incorporating calls for rain prayers into scientific models would be “validating [people’s] experience and telling them that it’s scientifically valid.”

The work also aligns with another goal for Ouaret, which is expanding the reach of open science in North Africa and other places underprioritized by Western researchers.

“Empowering people to do their science will help them so much to bring innovation to the whole community and bring a new way of addressing our traditional problems,” he said.

—Nathaniel Scharping (@nathanielscharp), Science Writer

Citation: Scharping, N. (2025), When a prayer is also a climate signal, Eos, 106, https://doi.org/10.1029/2025EO250450. Published on 3 December 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Two years of war in Gaza have taken a devastating toll on the people living there. Nearly 70,000 people, including more than 20,000 children, have been killed by Israeli attacks. Disease and famine have taken hold as Israel blocks the flow of food and medical aid into the territory. Several international human rights organizations have determined that Israel is committing genocide against Palestinians in Gaza.

Alongside the human casualties and the destruction of homes and infrastructure, the war has brought the widespread destruction of arable land. Agriculture comprised 32% of land use in Gaza before 7 October 2023, when Hamas, a recognized terrorist organization supporting Palestinian self-determination, attacked Israeli communities in Gaza and Israel launched a massive military response.

A recent analysis has tracked the destruction of tree cropland and greenhouses in Gaza since the start of the war. The analysis revealed that 70% of tree cropland and 58% of greenhouses were damaged or destroyed in the first year of the conflict. By the end of October 2025, 98% of Gaza’s tree cropland had been destroyed. Ninety percent of greenhouses were damaged, and 75% were destroyed.

“After 2 years, we see that most of the greenhouses are gone and the remaining tree cover is largely gone.”

“Now, after 2 years, we see that most of the greenhouses are gone and the remaining tree cover is largely gone,” said Mazin Qumsiyeh, a biologist and social justice advocate at Bethlehem University in the West Bank and a researcher on the project. He said that over the past 2 years, Gaza has endured an ecocide of agricultural lands.

“This is unprecedented damage,” said He Yin, a geographer and remote sensing researcher at Kent State University in Ohio and lead researcher on the project. “I have never seen anything like this,” said Yin, who previously studied other areas of armed conflict, including Syria and the northern Caucasus. Gaza, he said, has “become like a barren land.”

Gazan Agriculture Before the War

Farmers have been cultivating crops in Gaza and the surrounding land for thousands of years. Olive trees, in particular, have played an important cultural role throughout Palestinian and Israeli history, featuring prominently in celebrations, art, literature, and religion.

Prior to October 2023, Gaza’s agricultural sector made up 11% of the territory’s gross domestic product (roughly $575 million) and 45% of its exports. Palestinian farmers cultivated olive and citrus trees, as well as grapes, guava, dates, palms, and figs. More delicate fruits, vegetables, and flowers were grown in tunnels or other protective structures like greenhouses.

“Like everything else in Gaza, people managed and survived and resisted and did agriculture.”

“Gaza was not self-sufficient in foods, but [it] did produce significant number of products,” Qumsiyeh said. Despite Israel blocking rainwater harvesting and severely restricting Palestinian access to a shared aquifer, “like everything else in Gaza, people managed and survived and resisted and did agriculture,” he said.

The agricultural sector contributed to Palestinians’ food and economic security. Of Gaza’s 365 square kilometers of land, roughly 32% of it was used to grow food, mostly on small-scale family farms. Tree crops covered 23% of the Gaza Strip. Exports like olive oil, strawberries, and flowers found purchase in high-income markets across Europe, Qumsiyeh said, as well as the West Bank. And in years with enhanced drought or poor harvests, selling high-quality, shelf-stable products like olive oil could provide for a family in need.

Now, after 2 years of war, most agricultural land has been destroyed. Pinning down where, when, and how that happened is necessary for recovery and remediation, explained Najat Aoun Saliba, an atmospheric chemist at the American University of Beirut in Lebanon.

Saliba, also a member of Lebanon’s parliament, has studied the impacts of war-related pollutants on public and environmental health in Lebanon but was not involved with the new research about Gaza. Israel has used many of the same types of munitions to attack Gaza as it has to attack southern Lebanon, and Saliba suspects that the long-term environmental damage in Gaza might mirror what she has seen in her own country.

“The long-term environmental impacts of munitions include persistent heavy-metal and explosive residue contamination; persistent phosphorous materials that were used heavily at least in southern Lebanon; [unconfirmed] presence of radioactive materials…especially in the bunker buster ammunitions; reduced soil fertility and microbial imbalance; groundwater pollution and loss of irrigation capacity; and heightened erosion and desertification risks,” Saliba said.

Tracking the Destruction This animation tracks the damage to tree cropland in Gaza from October 2023 to October 2025. Undamaged croplands are colored green and turn purple in the month in which they sustained damage. Credit: Maps: He Yin, with data from Yin et al., 2025, https://doi.org/10.1016/j.srs.2025.100199, CC BY-NC-ND 4.0; Animation: Mary Heinrichs/AGU

The United Nations Satellite Center (UNOSAT) has been remotely monitoring the destruction of buildings, land, and infrastructure in Gaza since the start of the war. Their monthly agricultural damage assessments have shown widespread damage, but their methodology has some limitations when applied to a region as small as Gaza, Yin explained.

UNOSAT relies on data from the Sentinel-2 satellite, which has a nominal spatial resolution of 10 meters; that might not be the best choice for monitoring Gaza’s small-scale and sometimes fragmented agricultural land. What’s more, in such a rapidly evolving conflict, a monthly observing cadence is not able to track the progression of damage or trace the destruction of individual plots to specific military actions.

To overcome those challenges, Yin and his team turned to two commercial satellite data sources with higher spatial resolutions and daily monitoring: PlanetScope, with a nominal 3-meter resolution, and SkySat, with a nominal 50-centimeter resolution. The higher-resolution datasets allowed the team to create detailed land use maps of Gaza before October 2023, including tree cropland and greenhouses, and then track partial damage or total destruction of those plots every day since Israel’s war commenced.

Most of Gaza’s greenhouses have been damaged or destroyed during 2 years of war. The maps show how damage to greenhouses began in the north and progressed south. Undamaged greenhouses are marked with white circles, and damaged or destroyed greenhouses are marked with red circles. Greenhouses damaged or destroyed between October 2023 and October 2024 are on the left. Greenhouses damaged or destroyed between October 2024 and October 2025 are on the right. Credit: He Yin, with data from Yin et al., 2025, https://doi.org/10.1016/j.srs.2025.100199, CC BY-NC-ND 4.0

The researchers compared their damage maps to UNOSAT’s to validate their technique. They further validated their remote sensing results by consulting with Yaser Al A’wdat from the Palestine Ministry of Agriculture in Gaza and with other individuals on the ground, who checked whether certain areas flagged in the analysis as “destroyed” truly were. Those consultants in Gaza declined to be interviewed for this story out of concern for their safety.

The initial analysis covered the destruction of agricultural land through the first year of the war and was published in Science of Remote Sensing in February. The researchers found that 64%–70% of tree crop fields and 58% of greenhouses had been damaged by the end of September 2024, after almost 1 year of war. By the end of 2023, all greenhouses in the North Gaza and Gaza City governorates had been damaged, as well as nearly all greenhouses in the Gazan governorate of Deir al-Balah. The analysis showed how damage to both cropland and greenhouses progressed southward toward Khan Yunis and Rafah as Israel’s military campaign shifted focus.

The team continued its analysis through the second full year of the war, and those results, which will be presented on 18 December at AGU’s Annual Meeting 2025 in New Orleans, reveal the near-total destruction of tree cropland (98%) and increasing damage to greenhouses (90% damaged and 75% destroyed). Greenhouses in Rafah, in particular, suffered extensive and widespread damage as Israel’s military operation advanced south.

Remediate, Replant, Restore

Although a shaky (and repeatedly violated) ceasefire went into effect on 10 October, restoration and remediation will take time and very careful planning.

“Research like this can play a critical role in restoration and recovery efforts in Gaza by providing an evidence-based foundation for agricultural rehabilitation.”

“Research like this can play a critical role in restoration and recovery efforts in Gaza by providing an evidence-based foundation for agricultural rehabilitation,” Saliba said.

“This type of spatial assessment allows policymakers and humanitarian agencies to plan sequenced restoration—starting with fast-growing crops before replanting long-term trees like olives and citrus—and to design targeted compensation and replanting programs based on verified damage maps,” she added.

Future analyses seeking to map the scope of agricultural damage, as well as efforts to remediate that damage, should incorporate the food-energy-water nexus, Saliba said. “Because no agriculture restoration could happen without providing water.”

As focus turns toward restoration, the first thing that is needed are data, Qumsiyeh said. “For example, we don’t know the extent of soil contamination in Gaza and what residues of war are there, whether depleted uranium or white phosphorus or heavy metals and other things,” he said. “We don’t even have access to get the soil samples out of Gaza.”

There is also increased concern about aquifer contamination. When Israel flooded tunnels in Gaza with seawater, some of that water undoubtedly seeped through the ground into the aquifer that supplies most of the territory. In addition, Gaza has now seen three rainy seasons since the start of the war.

“All of that water from the rain will wash these pollutants from the soil down into the water aquifer,” Qumsiyeh said. “Again, we don’t have the data because we don’t have samples of water from the water aquifer to be able to test.”

If there were stronger international laws related to ecocide, Qumsiyeh said, data like that could hold those responsible to account.

At present, Israeli troops have partially retreated from the territory, but the area they still occupy beyond the so-called Yellow Line comprises much of Gaza’s agricultural land and is inaccessible to Palestinian farmers. According to the United Nations Office for the Coordination of Humanitarian Affairs, Israel continues to block the entry of agricultural inputs like seed kits, organic fertilizers, and materials needed to rebuild greenhouses.

“Agriculture is part of life. We are part of the land,” Yin said. Ultimately, “who has the power to rebuild Gaza really matters.”

—Kimberly M. S. Cartier (@astrokimcartier.bsky.social), Staff Writer

Citation: Cartier, K. M. S. (2025), 98% of Gaza’s tree cropland destroyed by Israel, Eos, 106, https://doi.org/10.1029/2025EO250447. Published on 3 December 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Editors’ Vox is a blog from AGU’s Publications Department.

In May 2023, a group of scientists gathered in Agros, Cyrpus, for an AGU Chapman Conference, “Hydrothermal Circulation and Seawater Chemistry: What’s the Chicken and What’s the Egg?” They discussed the role of hydrothermal fluxes in regulating ocean biogeochemistry and the Earth system. To share key finding from that conference—and other groundbreaking research on hydrothermal systems—the AGU book Hydrothermal Circulation and Seawater Chemistry: Links and Feedbacks came to life.

The latest volume in AGU’s Geophysical Monograph Series, this book explores on- and off-axis hydrothermal systems, boundary conditions such as climate and sedimentation history, and approaches for tracking oceanic processes. We asked the book’s Volume Editors about the latest methods and techniques, practical applications, and the future of the field of study.

In simple terms, what is hydrothermal circulation as it relates to seawater chemistry?

Hydrothermal circulation in this context is the flow of seawater through ocean crust.

Hydrothermal circulation in this context is the flow of seawater through ocean crust. It occurs at high-temperatures at mid-ocean ridges and at lower temperatures across much of the seafloor.

Along mid-ocean ridges, high-temperature (~400°C) reactions between seawater and crust turn the circulating seawater into hydrothermal fluids that become enriched in many elements such as potassium, calcium, and iron. Because these hot fluids are much less dense than cold seawater, the fluid flows rapidly upwards and vents at the seafloor. Cooling leads to precipitation of dissolved constituents forming chimney structures and particles carried by the fluid (the well-known “black smoke”). Other dissolved ions stay in solution and are added to the ocean, changing the composition of the seawater.

Hydrothermal circulation farther from mid-ocean ridges typically heats seawater by only 5–10°C and changes the chemical composition of the fluid much less than that of the hotter fluids. However, orders of magnitude more seawater circulates through low-temperature systems than high-temperature systems, making them equally important to seawater chemistry.

How do various boundary conditions impact hydrothermal processes in the ocean, and why is it important to study them?

The amount of fluid that flows through mid-ocean ridge hydrothermal systems depends on the geodynamic boundary conditions that control characteristics such as the average global rate of accretion of new oceanic crust and its thickness. These boundary conditions also control the types of rocks that make up the ocean crust, which impacts fluid–rock reactions and hence the composition of the fluid vented into the ocean. The composition and temperature of the deep seawater that circulates into the crust are also important boundary conditions controlling fluid–rock reactions and have both changed substantially over Earth’s history. For example, changes in the redox state of seawater over Earth’s history changed fluid–rock reactions and in-turn hydrothermal fluxes into the ocean.

What are the latest methods and techniques for studying hydrothermal circulation discussed in the book?

The book covers the latest methods and techniques for advancing various interdisciplinary fields focused on hydrothermal vents.

The book covers the latest methods and techniques for advancing various interdisciplinary fields focused on hydrothermal vents. For example, deploying novel instrumentation in the harsh conditions of high-pressure and high-temperature seafloor hydrothermal systems is improving studies of hydrothermal systems. Attaching instruments, such as Raman spectrometers and mass spectrometers, to seafloor cabled observatories will provide new insights into the dynamics of hydrothermal systems. Advancements in instrumentation will also significantly benefit the study of diffuse flow along mid-ocean ridges where fluids vent at tens of degrees Celsius rather than the much higher temperatures characteristic of “black smokers.” Diffuse venting circulates much more water, and probably more heat, than black smoker venting and yet has received only a fraction of the study. Scientists studying low-temperature seafloor hydrothermal systems distributed across the seafloor are starting to borrow methods used for studying continental weathering systems, which should lead to rapid progress being made in understanding these systems.

What practical applications do the studies presented in the book have for Earth system science?

Understanding the Earth system requires a quantitative understanding of the controls on global biogeochemical cycles. Currently, most models of global biogeochemical cycles either ignore hydrothermal systems or assume they do not change over time. However, there is now copious evidence that the fluxes of elements into and out of seawater due to hydrothermal systems are dependent on environmental conditions (e.g., climate, seawater chemistry) and hence do change over time. Furthermore, there can be feedbacks between the environment and the hydrothermal fluxes. This book will help people modeling the Earth system to better incorporate hydrothermal systems into biogeochemical models. In turn, the results of such models will become more robust.

Octopi brooding their eggs in warm water venting from the ocean crust near Davidson Seamount underwater volcano at a depth of 3,200 meters. Credit: Chad King / OET, NOAA

Where do you see the study of hydrothermal systems heading in the next 10 years?

The book features many exciting directions that the study of hydrothermal systems will hopefully take in the next decade. For example, there is a pressing need for more intense study of seafloor weathering until we understand it as well as we understand continental weathering. Expanding the availability of novel instruments that can be deployed at hydrothermal vents at mid-ocean ridges will advance the understanding of hydrothermal systems (e.g., during volcanic eruptions that are currently poorly understood). Vast potential also exists to better incorporate hydrothermal processes into Earth system models. Finally, a growth area for future research will be the role of hydrothermal systems on exoplanets and in the search for other habitable bodies. For example, NASA’s ongoing Clipper Mission to Jupiter’s moon Europa will hopefully enrich our understanding of the role of hydrothermal activity in controlling the habitability of this body.

How is the book organized?

After an introductory chapter, the next six chapters address hydrothermal processes at mid-ocean ridges. They consider both black smoker and diffuse flow systems, as well as the impact of these systems on the water column above mid-ocean ridges. The methods used to study hydrothermal systems, both in the lab and field, are also covered. An example of the fingerprint of changes in axial hydrothermal processes through changing seawater chemistry is discussed next. This is followed by three chapters about low-temperature hydrothermal systems that discuss how much more we have to discover about these systems. The last four chapters address the role of oceanic hydrothermal systems on planetary scale processes, both on Earth and other rocky bodies. They discuss how global-scale models work, how hydrothermal processes can be incorporated in such models, and how hydrothermal systems might work on other rocky bodies.

Who is the intended audience of the book? 

The audience for the book is intended to be broad—anyone interested in oceanic hydrothermal systems and/or ocean chemistry. People who are new to the field can use the book to get up-to-speed on ongoing interdisciplinary research in this area. This includes new graduate students or experienced researchers who have not previously considered the role of oceanic hydrothermal system in ocean chemistry. The book can also act as a starting point for researchers who develop global biogeochemical cycle models and who want to incorporate hydrothermal fluxes into these models. Finally, the book will appeal to people interested in planetary habitability and the role that hydrothermal systems may play in making other rocky bodies habitable, or the role hydrothermal systems may have played in nurturing early life on Earth.

Hydrothermal Circulation and Seawater Chemistry: Links and Feedbacks, 2025. ISBN: 978-1-394-22915-4. List price: $225 (hardcover), $180 (e-book)

Chapter 1 is freely available. Visit the book’s page on Wiley.com and click on “Read an Excerpt” below the cover image.

—Laurence A. Coogan (lacoogan@uvic.ca; 0000-0001-7289-5120), University of Victoria, Canada; Alexandra V. Turchyn (0000-0002-9298-2173), University of Cambridge, United Kingdom; Ann G. Dunlea (0000-0003-1251-1441), Woods Hole Oceanographic Institution, United States; and Wolfgang Bach (0000-0002-3099-7142), University of Bremen, Germany

Editor’s Note: It is the policy of AGU Publications to invite the authors or editors of newly published books to write a summary for Eos Editors’ Vox.

Citation: Coogan, L. A., A. V. Turchyn, A. G. Dunlea, and W. Bach (2025), Hydrothermal circulation and its impact on the Earth system, Eos, 106, https://doi.org/10.1029/2025EO255036. Published on 3 December 2025. This article does not represent the opinion of AGU, Eos, or any of its affiliates. It is solely the opinion of the author(s). Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Journal of Geophysical Research: Space Physics

Earth is surrounded by rings of energetic particles called radiation belts. The inner belt can sometimes be populated by megaelectron volt (MeV) energetic electrons during particularly strong solar storms. When moved by electromagnetic waves, these energetic particles can rain into the atmosphere.

Feinland and Blum [2025] show that periodic signatures of relativistic electron rain observed by satellites can be used to better predict when and where they might happen in the future. The authors find that these high-energy electrons usually came into the inner belt quickly after solar storms and gradually rained out over the course of a few weeks. During particularly quiet solar conditions, there were no detectable high-energy electrons in this region at all. These results are important to incorporate into models of the radiation belts, to better characterize and predict the high radiation environment in near-Earth space.

Citation: Feinland, M. A., & Blum, L. W. (2025). Lightning-induced precipitation as a proxy for inner belt MeV electron decay times. Journal of Geophysical Research: Space Physics, 130, e2025JA034258. https://doi.org/10.1029/2025JA034258

—Viviane Pierrard, Editor, JGR: Space Physics

Text © 2025. The authors. CC BY-NC-ND 3.0
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The Serengeti is one of the most diverse ecosystems on Earth. The massive savanna stretches more than 30,000 square kilometers across Tanzania and southwestern Kenya, and conservation sites, including national parks and a United Nations Educational, Scientific and Cultural Organization World Heritage Site, mark its significance as one of the world’s last intact large-animal migration corridors.

Life in the Serengeti is shaped by interactions between herbivores, vegetation, fire, and rain. Every year, millions of wildebeest, zebras, and gazelles hoof it across the savanna for their great migration, an 800-kilometer loop through the Serengeti and Kenya’s adjacent Maasai Mara game reserve. The iconic migration is dictated by rainfall, with herbivores following the green grass brought by the rainy season.

New research documenting the far-reaching impact of increasing rainfall on the Serengeti will be presented on Monday, 15 December, at AGU’s Annual Meeting. Megan Donaldson, a postdoctoral researcher at Duke University’s Nicholas School of the Environment, and her colleagues will share how vegetation is consumed by both grazing herbivores and fire in the Serengeti and how that consumption is reflected in the landscape. Studies like Donaldson’s are emerging as an important area of research for scientists assessing how climate change will affect the closely intertwined biotic and abiotic components in tropical grassland ecosystems around the world.

“For now, we’re just looking at how those interactions are feeding back to each other, how increased rainfall is affecting the dynamics between vegetation, herbivores, and fire,” said Donaldson.

Rainfall, Fuel, and Food

Rainfall controls how much grass grows in the Serengeti: When rainfall is intense, grasses grow quickly.

That growth is consumed in two primary ways: by fire as fuel and by herbivores as food.

Fire can eradicate excess vegetation, which is why a previous rainy season in the Serengeti might be a reliable predictor for how much land will burn there in the near future.

More than 30 species of large herbivores consume vegetation in the Serengeti, each with its own ecological niche.

“Some are constantly on the move, others are residents, some are grazers, some browsers, others are mixed feeders, and they range in size from the minuscule dik-dik to the massive elephant. They all thrive together by seeking out seasonal sources of water and feeding differentially on the rich diversity and abundance of grasses, shrubs, and trees,” said Monica Bond, a wildlife biologist at the University of Zurich who was not part of the recent study.

Herbivores consume vegetation at a much slower rate than fire does. Under normal conditions, grazing herbivores keep grass levels low enough to reduce the spread of fire across large areas. But it can take several seasons for animal populations to adjust to differences in food availability, so as rainfall totals increase and cause explosive growth in savanna vegetation, herbivores are unable to maintain their ability to minimize the fuel available for wildfires.

In the new research, Donaldson and her colleagues examined weather station and camera trap data from sites inside Serengeti National Park in Tanzania.

In particular, the researchers tracked how recent shifts in the Indian Ocean Dipole caused rainfall totals to increase across the Serengeti. The Indian Ocean Dipole is a weather pattern similar to the El Niño–Southern Oscillation phenomenon that spawns El Niño or La Niña conditions in the Pacific. It alters wind, rain, and temperature conditions in East Africa. Between 2019 and 2024, mean rainfall totals in the Serengeti were 268 millimeters higher than in the period from 1999 through 2003.

The researchers found that within the park, rainfall was not uniform. “There’s a rainfall gradient. You get low rainfall in the south and high rainfall in the north,” said Donaldson.

In the northern Serengeti, surplus rainfall supported such rapid growth of grass that herbivore consumption had little influence on reducing the amount of fuel available for wildfires.

In the typically drier south, however, herbivores were able to keep grasses short enough to slow the buildup of fuel.

But during periods of increased rainfall, Donaldson explained, “we see that those feedbacks are quicker. You’re getting fuel buildup much quicker, and you need all the [animal] migrants to come through that system to have any effect on fire.”

Untangling a Complex Ecosystem

Between 2019 and 2024, fire size in the Serengeti increased, but the increase was more complex than “more fuel feeding more fires.”

“The number of fires necessarily isn’t changing; it seems to be staying stable,” explained Donaldson. “We’re not seeing this very strong correlation between increased rainfall and increased fire. What is driving that? Why are we seeing that? And what are herbivores doing to that? Those are the things we’re trying to tease apart right now.”

“Because the Serengeti is one of the few intact biologically functioning ecosystems left on the planet, it makes for a perfect natural laboratory.”

Future work from Donaldson and her colleagues will further researchers’ understanding of how the Serengeti’s four major players—herbivores, biomass, fire, and rainfall—connect.

“Because the Serengeti is one of the few intact biologically functioning ecosystems left on the planet, it makes for a perfect natural laboratory to study complex ecological interactions and how these are affected by climate change,” said Bond. “This research has important implications for fire management and thus for wildlife conservation in this ecologically critical landscape. It is incredible the research that they have done here in fostering understanding of how this system works.”

—Rebecca Owen (@beccapox.bsky.social), Science Writer

Citation: Owen, R. (2025), Tracing fire, rain, and herbivores in the Serengeti, Eos, 106, https://doi.org/10.1029/2025EO250444. Published on 2 December 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Our Sun is about halfway through its life, which means Earth is as well. After a star exhausts its hydrogen nuclear fuel, its diameter expands more than a hundredfold, engulfing any unlucky planets in close orbits. That day is at least 5 billion years off for our solar system, but scientists have spotted a possible preview of our world’s fate.

Elderly stars just get hungry.

Using data from the TESS (Transiting Exoplanet Survey Satellite) observatory, astronomers Edward Bryant of the University of Warwick and Vincent Van Eylen of University College London compared systems with stars in the main sequence of their lifetimes—fusing hydrogen, like the Sun—with post–main sequence stars closer to the end of their lifetimes, both with and without planets.

“We saw that these planets are getting rarer [as stars age],” Bryant said. In other words, planets are disappearing as their host stars grow old. The comparison between planetary systems with younger and older stars makes it clear that the discrepancy does not stem from the fact that the planets weren’t there in the first place: Elderly stars just get hungry.

“We’re fairly confident that it’s not due to a formation effect,” Bryant explained, “because we don’t see large differences in the mass and [chemical composition] of these stars versus the main sequence star populations.”

Complete engulfment isn’t the only way giant stars can obliterate planets. As they grow, giant stars also exert increasingly larger tidal forces on their satellites that make their orbits decay, strip them of their atmospheres, and can even tear them apart completely. The orbital decay aspect is potentially measurable, and this is the effect Bryant and Van Eylen considered in their model for how planets die.

“We’re looking at how common planets are around different types of stars, with number of planets per star,” Bryant said. Bryant and Van Eylen identified 456,941 post–main sequence stars in TESS data and, from those, found 130 planets and planet candidates with close-in orbits. “The fraction [of stars with planets] gets significantly lower for all stars and shorter-period planets, which is very much in line with the predictions from the theory that tidal decay becomes very strong as these stars evolved.”

Astronomers use TESS to find exoplanets by looking for the diminishment in light as they pass in front of their host stars, a miniature eclipse known as a transit. As with any exoplanet detection method, transits are best suited to large, Jupiter-sized planets in relatively small orbits lasting less than half of an Earth year, sometimes much less. So these solar systems aren’t much like ours in that respect. Studying planets orbiting post–main sequence stars poses additional challenges.

“If you have the same size planet but a larger star, you have a smaller transit,” Bryant said. “That makes it harder to find these systems because the signals are much shallower.”

However, though the stars in the sample data have a much greater surface area, they are comparable in mass to the Sun, and that’s what matters most, the researchers said. A star with the same mass as the Sun will go through the same life stages and die the same way, and that similarity is what helps reveal our solar system’s future.

“The processes that take place once the star evolves [past main sequence] can tell us about the interaction between planets and host star,” said Sabine Reffert, an astronomer at Universität Heidelberg who was not involved in the study. “We had never seen this kind of difference in planet occurrence rates between [main sequence] and giants before because we did not have enough planets to statistically see this difference before. It’s a very promising approach.”

Planets: Part of a Balanced Stellar Breakfast

Exoplanet science is one of astronomy’s biggest successes in the modern era: Since the first exoplanet discovery 30 years ago, astronomers have confirmed more than 6,000 planets and identified many more candidates for follow-up observations. At the same time, the work can be challenging when it comes to planets orbiting post–main sequence stars.

One tricky aspect of this work is related to the age of the stars, which formed billions of years before our Sun. Older stars have a lower abundance of chemical elements heavier than helium, a measure astronomers call “metallicity.” Observations have found a correlation between high metallicity and exoplanet abundance.

“A small difference in metallicity…could potentially double the occurrence rate.”

“A small difference in metallicity…could potentially double the occurrence rate,” Reffert said, stressing that the general conclusions from the article would hold but the details would need to be refined with better metallicity data.

Future observations to measure metallicity using spectra, along with star and planet mass, would improve the model. In addition, the European Space Agency’s Plato Mission, slated to launch in December 2026, will add more sensitive data to the TESS observations.

Earth’s fiery fate is a long way in the future, but researchers have made a big step toward understanding how dying stars might eat their planets. With more TESS and Plato data, we might even glimpse the minute orbital changes that indicate a planet spiraling to its doom—a grim end for that world but a wonderful discovery for our understanding of the coevolution of planets and their host stars.

—Matthew R. Francis (@BowlerHatScience.org), Science Writer

Citation: Francis, M. R. (2025), Planet-eating stars hint at Earth’s ultimate fate, Eos, 106, https://doi.org/10.1029/2025EO250448. Published on 2 December 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: GeoHealth

Heatwaves can disrupt many parts of daily life, including access to essential healthcare services. Dey et al. [2025] evaluate how heatwaves are related to where women in India give birth.

The authors analyze data from over 200,000 births during 2019-2021 and find that during periods of heatwaves, women were more likely to deliver at home instead of in a health facility. This association was stronger for warmer regions, regions without government programs supporting facility-based births, and non-Hindu populations. The study indicates that extreme heat may create barriers to healthcare services (e.g., difficulty traveling or strained health services), which makes it challenging to reach a hospital in time for delivery. This brings a major concern because giving birth at home without a skilled medical attendant may lead to higher health risks for both the mother and the newborn.

As the frequency and intensity of heatwaves increases under climate change, these findings emphasize the urgent need for early warning systems and stronger healthcare support to protect vulnerable mothers and newborns.

Citation: Dey, A. K., Dimitrova, A., Raj, A., & Benmarhnia, T. (2025). Heatwaves and home births: Understanding the impact of extreme heat on place of delivery in India. GeoHealth, 9, e2025GH001540. https://doi.org/10.1029/2025GH001540

—Lingzhi Chu, Associate Editor, GeoHealth

Text © 2025. The authors. CC BY-NC-ND 3.0
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Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: AGU Advances

Using data from the GRACE and GRACE-FO satellite missions, Rateb et al. [2025] monitored global changes in terrestrial water storage to study how hydrological extremes—floods and droughts—have developed over the past two decades. Their analysis indicates that these extremes are mainly driven by climate variability in tropical oceans, with both interannual and multi-year patterns playing a significant role.

However, the approximately 22-year satellite record is still too short to fully identify long-term drivers, which limits the ability to determine whether global extremes are increasing or decreasing. To fill data gaps in certain months, the authors use non-parametric probabilistic methods to reconstruct storage anomalies. The reconstructed data closely matched independent datasets, confirming the reliability of their approach. Overall, the study highlights the need to extend satellite observations to capture multi-decadal climate variability and better distinguish natural fluctuations from human-induced changes.

Citation: Rateb, A., Scanlon, B. R., Pokhrel, Y., & Sun, A. (2025). Dynamics and couplings of terrestrial water storage extremes from GRACE and GRACE-FO missions during 2002–2024. AGU Advances, 6, e2025AV001684. https://doi.org/10.1029/2025AV001684

—Tissa Illangasekare, Editor, AGU Advances

Text © 2025. The authors. CC BY-NC-ND 3.0
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Since the first agricultural revolution, circa 10,000 BCE, humanity has adapted its farming practices to meet climatic variation. The genesis of early farming is even thought to have resulted from a shift in seasonal conditions that favored regular planting and harvesting intervals after the last ice age.

In the modern era, the necessity to adapt has led to expansive land use, fertilization, irrigation, and other agricultural routines—powered primarily by combusted carbon and freshwater extractions—to suit local environmental conditions and meet demands of growing populations. These practices have been a boon to food supplies, but they have also contributed to many of today’s climatic and environmental challenges.

Climate-smart practices have primarily been studied in small, controlled experiments, not at the extent needed to verify their effectiveness on a large scale.

Recognition of global crises with respect to climate change and biodiversity has motivated landmark international agreements such as the Paris Agreement and the Global Biodiversity Framework. The Paris Agreement legally binds participating nations to implement land use methods that mitigate emissions and actively remove carbon from the atmosphere.

One such set of modified land management practices, known collectively as climate-smart agriculture [U.S. Department of Agriculture, 2025], is lauded as a pragmatic, low-barrier pathway to manage climate change through nature-based atmospheric carbon removal and avoided emissions (related to both land use and livestock). However, these practices have primarily been studied in small, controlled experiments, not at the extent needed to verify their effectiveness—and help motivate their adoption—on a large scale.

Recently, soil carbon experts explored the utility of applying causal approaches to quantify soil carbon accrual and avoided emissions from large-scale land management interventions and to address concerns and uncertainties that are slowing their uptake [Bradford et al., 2025a]. Such approaches have long been applied in other contexts to measure and verify treatment efficacy. In particular, methods in medical science for studying vaccine efficacy broadly offer important insights for assessing climate-smart applications.

Accounting for Carbon

Climate-smart agriculture includes a variety of management practices such as cover cropping (planting noncash crops on otherwise fallow land), reducing or eliminating soil tilling, and diversifying crops. These applications can offer various cobenefits, including increased yields; greater soil water holding capacity; improved soil microbiomes; reduced erosion and runoff; enhanced control of pests, disease, and weeds; and greater soil nutrient availability that reduces the need for chemical fertilizers [U.S. Department of Agriculture, 2025].

Such benefits are linked to the idea that the applications either avoid losses or improve gains in soil organic matter. But can we measure how much they really help?

To account for carbon lost, gained, or stored in agricultural land, soil organic matter is typically measured by elemental analysis of soil samples in a laboratory. Amounts of carbon stored are determined by tracking changes in soil carbon stocks over time. Comparing results following the application of climate-smart agriculture approaches with those following business-as-usual practices provides a measure of the approaches’ effectiveness for carbon management.

Cover crop grows amid rows of corn stubble in a farm field in Deerfield, Mass. Credit: Lance Cheung, U.S. Department of Agriculture/Flickr, PDM 1.0

Assuming this carbon accounting reveals increased soil carbon stocks, agricultural projects implementing these approaches can be considered natural climate solutions, which are valued in the voluntary carbon market for their carbon offset and removal power. For example, one project developer selling carbon credits since 2022 recently reported that their efforts have so far stored nearly 1 million tons of soil carbon in U.S. farmlands. Further, across farms in four U.S. states, the combined use of three climate-smart agriculture techniques—no tillage, cover cropping, and crop rotation of corn and soybeans—is claimed to have resulted in a shift to carbon gains from soil carbon loss using conventional practices [U.S. Department of Agriculture, 2025].

Limited Evidence, Low Adoption

Despite claims about the successes of climate-smart agricultural practices, adoption remains low. Although no-till and reduced-till methods have been implemented on more than half of all U.S. soybean, corn, and sorghum fields, cover cropping is used across less than 5% of the country’s agricultural lands.

If robust data showing that climate-smart practices lead to widespread yield increases, cost reductions, and climate benefits were available, they might be more widely adopted by growers.

A multitude of social, cultural, and economic factors—along with questions about the viability for meaningful climate change mitigation—contribute to the limited adoption of some climate-smart practices [Prokopy et al., 2019; Eagle et al., 2022]. However, if robust data showing that they lead to widespread yield increases, cost reductions, and climate benefits were available, they might be more widely adopted by growers.

Presently, most evidence supporting the benefits of climate-smart agriculture for carbon management relies on a limited set of small-plot experimental trials and projected outcomes derived from applying process-based biogeochemical models. Public and private investment in studies aimed at quantifying the practices’ efficacy through measurement, monitoring, reporting, and verification (MMRV) at scales of real-world commercial agriculture has been inhibited by the assumption that soils vary too much to measure treatment effects feasibly [Poeplau et al., 2022].

This assumption is driven by the fact that regional and national soil carbon inventories reveal substantial variation in soil carbon contents at scales within individual fields (meters to tens of meters) and between fields (kilometers to tens of kilometers)—variation that is thought to preclude detections of how agricultural practices affect carbon stocks [Bradford et al., 2023]. Yet this variability can be overcome by scaling up field-level data to multifield scales focused on understanding the average effect of interventions.

What could this scaling look like, and what cues from other fields can we use to make progress?

Adapting Methods from Medical Research

Causal approaches are used regularly in health sciences, including in vaccine trials. In later-stage trials, vaccine efficacy is quantified under conditions approximating real-world delivery by measuring the differences in the health responses of people who receive the vaccine and those who do not.

Public health scientists use large-scale clinical intervention-style experiments to account for factors that can modify real-world vaccine efficacy. Earth scientists can take direction from such trials.

Importantly, such real-world trials occur only after there is enough experimental evidence—typically from controlled laboratory experiments and small-scale clinical trials—of underlying mechanisms indicating the likelihood of broad, meaningful positive effects and minimal negative effects of the vaccine. Public health scientists use these large-scale clinical intervention-style experiments (or observational studies) to account for factors such as varied exposure risks and preexisting conditions that can modify real-world vaccine efficacy compared with efficacy under controlled conditions.

Earth scientists can take direction from such trials. Adapting this experiment structure for soil science research would allow project developers, scientists, land managers, and policymakers to assess the ability of climate-smart agricultural practices to store carbon and reduce emissions across real fields and farms. It would also better inform meaningful climate action policy initiatives.

A base of highly controlled small-scale experiments—typically conducted in plots operated by researchers—already exists that suggests the carbon benefits of improved agricultural practices under highly controlled conditions. What is missing are the large-scale intervention studies sampling soil carbon in fields that receive a climate-smart treatment (e.g., no till or reduced till, crop rotation, cover cropping) versus those that are conventionally managed [Bradford et al., 2025b].

Such studies must be undertaken with appropriate design principles to confirm whether treatment interventions cause measured carbon gains and to focus on the external validity of the experiments. In the case of climate-smart agriculture, “external validity” refers to the extent to which a study’s results are applicable to other fields receiving similar management interventions. Achieving external validity necessitates sustained observation of realistic intervention behaviors on working commercial farms and on well-defined and preserved control fields, repetition of experiments at a variety of sites, and quantification of average outcomes from interventions across fields rather than for individual fields.

Empirical causal studies at the regional scales of commercial agricultural practices should be the gold standard of evidence for evaluating the effectiveness of climate-smart approaches.

New research suggests that empirical measure-and-remeasure projects are scientifically feasible at regional agricultural scales using current best practices for soil sampling and carbon analysis [Potash et al., 2025; Bradford et al., 2023]. Potash et al. [2025], for example, simulated a randomized-controlled trial for intervention projects across hundreds to thousands of fields, incorporating known variations in soil carbon stocks and measurement errors. The results showed that such projects can reliably estimate the effects of the treatments applied.

Using causal empirical approaches can complement, rather than compete with, the development of other approaches for MMRV of carbon storage and emissions. Approaches using satellite and airborne remote sensing may, for example, enable more efficient scaling of climate mitigation projects, albeit only if they are first validated against causal empirical data.

Empirical causal studies at the regional scales of commercial agricultural practices should thus be the gold standard of evidence for evaluating the effectiveness of climate-smart approaches. Data from these experiments will provide a rigorous basis for independent validation of established and emerging digital- and model-based approaches for soil carbon MMRV. They will also build confidence that adopting climate-smart practices really does result in mitigation of carbon emissions and climate change under real-world conditions.

Acknowledgments

The perspectives presented here were informed by discussions at and outcomes from a workshop convened in October 2024 by researchers at Yale University and the Environmental Defense Fund. Funding support was provided by the Yale Center for Natural Carbon Capture and gifts to the Environmental Defense Fund from King Philanthropies and Arcadia, a charitable fund of Lisbet Rausing and Peter Baldwin.

References

Bradford, M. A., et al. (2023), Testing the feasibility of quantifying change in agricultural soil carbon stocks through empirical sampling, Geoderma, 440, 116719, https://doi.org/10.1016/j.geoderma.2023.116719.

Bradford, M. A., et al. (2025a), Agricultural soil carbon: A call for improved evidence of climate mitigation, Yale Applied Science Synthesis Program and Environmental Defense Fund white paper, Yale Appl. Sci. Synth. Program, New Haven, Conn., https://doi.org/10.31219/osf.io/uk3n2_v1.

Bradford, M. A., et al. (2025b), Upstream data need to prove soil carbon as a climate solution, Nat. Clim. Change, 15, 1,013–1,016, https://doi.org/10.1038/s41558-025-02429-4.

Eagle, A. J., N. Z. Uludere Aragon, and D. R. Gordon (2022), The realizable magnitude of carbon sequestration in global cropland soils: Socioeconomic factors, Environ. Defense Fund, New York, www.edf.org/sites/default/files/2022-12/realizable-magnitude-carbon-sequestration-cropland-soils-socioeconomic-factors.pdf.

Poeplau, C., R. Prietz, and A. Don (2022), Plot-scale variability of organic carbon in temperate agricultural soils—Implications for soil monitoring, J. Plant Nutr. Soil Sci., 185, 403–416, https://doi.org/10.1002/jpln.202100393.

Potash, E., et al. (2025), Measure-and-remeasure as an economically feasible approach to crediting soil organic carbon at scale, Environ. Res. Lett., 20(2), 024025, https://doi.org/10.1088/1748-9326/ada16c.

Prokopy, L. S., et al. (2019), Adoption of agricultural conservation practices in the United States: Evidence from 35 years of quantitative literature, J. Soil Water Conserv., 74(5), 520–534, https://doi.org/10.2489/jswc.74.5.520.

U.S. Department of Agriculture (2025), Documentation of literature, data, and modeling analysis to support the treatment of CSA practices that reduce agricultural soil carbon dioxide emissions and increase carbon storage, Off. of the Chief Econ., Off. of Energy and Environ. Policy, Washington, D.C., www.usda.gov/sites/default/files/documents/USDA_Durability_WhitePaper_01_14.pdf.

Author Information

Savannah Gupton (savannah.gupton@yale.edu), Applied Science Synthesis Program, The Forest School at the Yale School of the Environment, Yale Center for Natural Carbon Capture, Yale University, New Haven, Conn.; Mark Bradford, Alex Polussa, and Sara E. Kuebbing, The Forest School at the Yale School of the Environment, Yale Center for Natural Carbon Capture, Yale University, New Haven, Conn.; and Emily E. Oldfield, Environmental Defense Fund, New Haven, Conn.; also at Yale School of the Environment, Yale University, New Haven, Conn.

Citation: Gupton, S., M. Bradford, A. Polussa, S. E. Kuebbing, and E. E. Oldfield (2025), How can we tell if climate-smart agriculture stores carbon?, Eos, 106, https://doi.org/10.1029/2025EO250446. Published on 1 December 2025. This article does not represent the opinion of AGU, Eos, or any of its affiliates. It is solely the opinion of the author(s). Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Early in the time-twisting, exoplanet-exploring film Interstellar, a scientist on a blight-plagued Earth stares at corn in a greenhouse, watching the crop die. That scene, said Northern Arizona University doctoral candidate Laura Lee, got her thinking about growing food in difficult soils.

The idea propelled Lee, a planetary scientist and astronomer, into a new project, studying how the outer veneer of planetary bodies might be enriched to sustain crops needed for future human settlements. At AGU’s Annual Meeting 2025 on 16 December, Lee will present findings about how various amendments, such as fungi, urea-based fertilizer, and even poop, could help plants like corn grow on the Moon and Mars.

Necessary Ingredients

Plants need 17 specific elements to survive. Carbon, hydrogen, and oxygen combine to form cellulose—the building blocks of cell walls. Nitrogen helps lush green leaves flourish. Phosphorous stimulates stability-providing roots. Iron, potassium, and other nutrients are also critical for plants to function.

“If you can avoid bringing all that up, it’s super advantageous. Mass is really expensive.”

But on the Moon and Mars, the regolith—the loose outer layer of any planetary body—lacks some of these plant essentials. For instance, lunar regolith contains almost no carbon or nitrogen, said Steve Elardo, a planetary geochemist at the University of Florida who was not involved in Lee’s study.

Plus, the phosphorus that is present, at least on the Moon, isn’t in a useful form for plants, said Jess Atkin, a doctoral candidate and space biologist at Texas A&M who studies how microbes can remediate regolith to grow plants on the Moon.

Taking terrestrial soil to space is not ideal because of cost. “If you can avoid bringing all that up, it’s super advantageous,” Elardo said. “Mass is really expensive.” Taking microbes to the Moon, on the other hand, is a much lighter option.

What’s in a Regolith?

Scientists rely on data from rovers, landers, and satellite remote sensing to understand the chemistry of Martian regolith. The Apollo missions brought back 382 precious kilograms (842 pounds) of the Moon. The Chang’e and Luna missions combined brought back another ~4 kilograms of lunar samples. Because of the limited supply of real lunar regolith, most planetary crop studies, including Lee’s, rely on something called simulant, a synthetic imitation of extraterrestrial regolith.

For her experiments, Lee selected two simulants from Space Resource Technologies: one of the lunar highlands and one that approximates Martian regolith on the basis of data from both remote sensing and the Curiosity rover. But because of the lack of necessary nitrogen in both simulants, Lee tested two nitrogen-bearing media to introduce this key ingredient.

For the first, she used a synthetic urea-based fertilizer used by many home gardeners. For the second, Lee used Milorganite—a nitrogen-rich biosolid made from processing human waste produced by the population of Milwaukee, Wis. For Lee, the Milorganite imitates a nutrient-rich resource that future astronauts heading to planetary bodies will certainly have and that shouldn’t add weight to the mission payload: their own waste.

The hardened final remains from a sewage plant are called sludge or biosolids. The semisolid leftovers form desiccation cracks as they dry. This image is from a sewage plant in Kos, Greece. Credit: Hannes Globe/Wikimedia Commons, CC BY-SA 2.5

“When they’re adding human waste, the best thing they’re doing is adding organic matter” that can also help bind regolith particles together, said Atkin, who was not involved with Lee’s study.

“You can go full Mark Watney on this,” said Elardo, referencing the 2015 film The Martian, in which a botanist astronaut amends Martian regolith with the crew’s biosolids to grow potatoes. “If you compost [astronaut waste] and make it safe…it should provide a pretty good fertilizer.”

Fabulous Fungi

Lee also tested how crops grew with and without arbuscular mycorrhizae, a microscopic, symbiotic interconnection between certain fungi and the plant roots in which they reside.

“It extends that root zone, giving stability,” Atkin said, “like a glue in our soil.” The plant provides carbon to the fungi, and the fungi transfer water and nutrients, particularly phosphorus, to the plant, she explained.

In the fertilizer-only experiments, Lee found that plants grown in lunar simulant with Milorganite tended to grow larger, but in comparison, plants grown in lunar simulant with urea-based fertilizer were more likely to survive the 15-week growing period. For the Martian simulant, no plants survived in Milorganite.

There is a huge ethical question about bringing microorganisms to extraterrestrial places.

The fertilizer-only experiments provided a control to help Lee assess what happens with the addition of fungi. In the lunar experiments with fungi, no matter which nitrogen fertilizer source was used, plants grew larger than in the fertilizer-only trials. Lee also found higher chlorophyll levels in the leaves of plants grown with fungi and Milorganite. These results are signs that fungi facilitate healthier plants. Plants grown in Martian simulant amended with either fertilizer option also fared better with the addition of fungi. Although only a single plant out of six survived in Martian simulant amended with Milorganite and arbuscular mycorrhizae, this plant “produced the highest chlorophyll levels across all lunar and Martian corn, and produced the most biomass out of all plants grown in Martian regolith,” Lee wrote in an email.

“There is a huge ethical question about bringing microorganisms” to extraterrestrial places, said Lee, whether in the form of fertilizer or fungi. But any future astronauts will introduce microorganisms to the Moon and Mars via their own microbiomes, she said. Plus, 96 bags of human waste already languish on the lunar surface, divvied up between the six Apollo landing sites.

Simulant Versus Regolith

In an experiment published in 2022, a team of scientists including Elardo demonstrated that lunar regolith collected during Apollo 11, 12, and 17 could grow a plant called Arabidopsis thaliana, or thale cress. But the plants were stressed. “They grew, but they were not particularly happy,” Elardo said. The same plants produced healthy roots and shoots when grown in lunar simulants.

These findings demonstrated that for biology purposes, “[simulants] don’t capture the chemistry of extraterrestrial regoliths,” Elardo said, in part because that’s not always what simulants are designed to do. Several are made by the truckload for large-scale engineering projects, like testing the wheels of a rover destined for Mars, he explained. Moreover, the Moon’s iron isn’t in the same state as Earth’s, and it’s a version plants don’t want. Plus, real lunar regolith grains are extremely sharp and shard-like, impeding the progress of delicate roots.

Nevertheless, comparative studies such as Lee’s might be useful, Elardo said. “Can you add a fungus…that increases nutrient uptake?” he pondered. “That’s an awesome idea.”

—Alka Tripathy-Lang (@dralkatrip.bsky.social), Science Writer

Citation: Tripathy-Lang, A. (2025), Fungi, fertilizer, and feces could help astronauts grow plants on the Moon, Eos, 106, https://doi.org/10.1029/2025EO250445. Published on 1 December 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

body {background-color: #D2D1D5;} Research & Developments is a blog for brief updates that provide context for the flurry of news regarding law and policy changes that impact science and scientists today.

The U.S. Environmental Protection Agency moved this week to reduce limits on fine particulate air pollution, including soot, set by the Biden administration last year. 

The administration gave up defense of a rule which lowered the standard for air pollution particles measuring less than 2.5 micrometers in diameter, also known as PM2.5. The rule, which would have been fully implemented in 2032, took the standard from 12 micrograms of PM2.5 per cubic meter of air to 9. Such tiny particles, which come from vehicle exhaust, factories, and power plants, are especially harmful to human health because they can infiltrate the lungs and the bloodstream. 

In 2024, EPA estimated the 9-microgram standard could prevent up to 4,500 premature deaths, 2,000 hospital visits, and 800,000 cases of asthma per year. 

“An abundance of scientific evidence shows that going back to the previous standard would fail to provide the level of protection for public health required under the Clean Air Act.”

On 24 November, EPA asked the U.S. Court of Appeals for the D.C. Circuit to strike down the new standard, abandoning its defense against industry trade associations and attorneys general from conservative states that had sued Biden’s EPA over the rule.

In the court filing, EPA took the side of its challengers, stating the rule was created “without the rigorous, stepwise process that Congress required.”

“EPA now confesses error,” the filing said. Though the 9-microgram standard remains in effect currently, the EPA proposed in its filing that the standard revert to the 12-microgram rule finalized in 2020.

Environmental groups said the action undermines the agency’s obligations under the Clean Air Act. “EPA’s motion is a blatant attempt to avoid legal requirements for a rollback, in this case for one of the most impactful actions the agency has taken in recent years to protect public health,” Hayden Hashimoto, an attorney for the Clean Air Task Force, a nonprofit, told AP. “An abundance of scientific evidence shows that going back to the previous standard would fail to provide the level of protection for public health required under the Clean Air Act.”

Particulate air pollution disproportionately affects Black communities and other communities of color, as well as low-income groups. One 2018 study found that people living in poverty were exposed to 35% more PM2.5 than the overall population, and Black people were exposed to 54% higher amounts.

 
Related

•  EPA to Abandon Air Pollution Rule That Would Prevent Thousands of U.S. Deaths
•  Trump EPA Moves to Abandon Rule That Sets Tough Standards for Deadly Soot Pollution
•  EPA: Health and Environmental Effects of Particulate Matter (PM)
• Some Communities Feel the Effects of Air Pollution More Than Others
•  Get Involved: AGU Science Policy Action Center

In April, a coalition of public health and community groups wrote a letter to EPA Administrator Lee Zeldin asking him to quickly implement the strengthened standard. “There is no legally viable basis for weakening it,” they wrote.

“Our communities already carry the burden of polluted air and higher rates of asthma and heart disease. Weakening soot protections will only deepen these disparities and cost more Black lives,” Yvonka Hall, executive director of the Northeast Ohio Black Health Coalition, one of the groups that signed the letter, said in a statement.

The move to vacate defense of the rule is part of a broader rollback of regulations on industrial facilities by the EPA. Earlier this year, the agency proposed repealing requirements for polluting facilities to report their greenhouse gas emissions. The EPA is expected to propose its own PM2.5 rule early next year.

—Grace van Deelen (@gvd.bsky.social), Staff Writer

These updates are made possible through information from the scientific community. Do you have a story about how changes in law or policy are affecting scientists or research? Send us a tip at eos@agu.org. Text © 2025. AGU. CC BY-NC-ND 3.0
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In Antarctica, beneath the ice, there is liquid water—and potentially a lot of it. That’s the takeaway from new research that used seismographic instruments to probe the still largely unstudied boundary between Antarctica’s bedrock and its ice sheet.

Previous hydrological studies and modeling work have found evidence of lakes and rivers beneath the Antarctic Ice Sheet, though much remains unknown about the region.

Now, using an array of seismic sensors, researchers from Stony Brook University have added more data points to the map of subglacial Antarctica, finding evidence of a layer of water-saturated sediments or rock under the ice. That layer could have implications for models of Antarctic groundwater systems, as well as for future movements of the ice sheet as it slides toward the ocean.

Looking Beneath the Ice with Earthquakes

The data, which will be presented at AGU’s 2025 Annual Meeting, come from an array of more than 600 seismic sensors strung in two long lines totaling about 600 kilometers near the South Pole, put there over the course of two field seasons in Antarctica. The sensors listen for seismic waves that travel through the upper layers of Earth and into the ice sheet.

Those waves carry the signatures of every medium through which they’ve traveled, said Weisen Shen, a geoscientist at Stony Brook University and a paper coauthor. To isolate that information, the researchers applied a mathematical technique called a receiver function to remove the waves’ source information, leaving only the signatures of what they moved through on their journey to the sensor.

In their data from beneath the South Pole, in a region known as the Pensacola-Pole Basin, the researchers found a very low velocity layer, where seismic waves travel too slowly for the conducting medium to be bedrock or ice.

While the authors can’t say exactly what this layer looks like, Shen said the best explanation is a layer of water-saturated sediments or sandstone, likely hundreds of meters thick.

“Anything we can do to try and enhance our knowledge of what’s going on…is just going to help us try and narrow down this really bizarre landscape underneath the ice.”

“We believe…there must be some aquifer system, a groundwater system, that must be preserved beneath the ice,” he said.

The water there could even be connected to groundwater elsewhere in Antarctica, Shen noted. If so, water might be moving around beneath the surface of Antarctica through hydrologically linked basins, and perhaps even out to the ocean.

That scenario could have implications for sea level rise, but, as University of Waterloo glaciologist Christine Dow pointed out, we know far too little to say for sure. In her own modeling, Dow, who wasn’t affiliated with the research, said it appears these basins aren’t connected to the ocean.

“But these are models based on our current knowledge of where’s frozen and where’s not under the Antarctic,” she said. “Perhaps this new information will change that.”

Dow welcomed new data on the mostly uncharted landscape of subglacial Antarctica, where scientists have evidence of lakes, rivers, and groundwater interacting in complex ways, but little hard evidence of the continent’s topography.

“Anything we can do to try and enhance our knowledge of what’s going on…is just going to help us try and narrow down this really bizarre landscape underneath the ice,” she said.

More Questions Than Answers

One question the new data raise is where the heat energy needed to melt the water comes from, noted Hanxiao Wu, a Ph.D. candidate at Stony Brook University and the paper’s first author. It could come from geothermal heat from below, friction caused by the movement of ice at the surface, or some combination of both.

One takeaway from the research is that estimates of geothermal heat flux below Antarctica may need to be bumped upward, Dow said. Models of ice sheet movement and evolution may also need to change to accommodate hundreds of meters of water-saturated sediments. “That’s a game changer,” Dow said.

Should there turn out to be more water beneath Antarctica than previously thought, and should that water move greater distances and in greater amounts, sea levels could rise beyond current predictions, Shen said. It’s too early, however, to estimate any of these probabilities with much certainty, he cautioned.

Right now, Shen and his fellow researchers are focused on improving their dataset and seeking collaborations with other geophysicists to map out the implications of their findings. Wu traveled back to Antarctica for the 2025–2026 field season, where the team is adding another line of seismic sensors to increase coverage and working on tracking the array to better understand changes in snow surface elevation.

In the future, they hope to add additional data from satellites, magnetotelluric surveys, and fiber-optic cables for a more comprehensive look at the ice pack and its underbelly, perhaps as part of the 5th International Polar Year in 2032.

What the scientists will find is unknown. But with millions of square miles of land underneath the ice, the potential for discovery is appropriately vast.

—Nathaniel Scharping (@nathanielscharp), Science Writer

Citation: Scharping, N. (2025), The land beneath Antarctica’s ice might be full of water, Eos, 105, https://doi.org/10.1029/2025EO250435. Published on 26 November 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Powerful summertime thunderstorms are injecting particulate matter from wildfires and additional moisture into the stratosphere—a layer of the atmosphere scientists have long thought was mostly pristine.

“The lower stratosphere almost looked more like a smoke cloud.”

A new study, published in Nature Geoscience, detailed these findings, which could have implications for Earth’s ozone layer and atmospheric circulation, especially as the climate continues to warm.

“We as atmospheric scientists have this preconceived notion that [the stratosphere] is a really stable, clean area of our atmosphere. We don’t think about it being perturbed all that often,” said Dan Cziczo, an atmospheric scientist at Purdue University and a coauthor of the new study. 

But in the new observations, “the lower stratosphere almost looked more like a smoke cloud,” he said.

Stratospheric Science

North America’s monsoon season starts when warm, moisture-laden air from the Gulf of Mexico collides with the Rocky Mountains. This process can create powerful summer storms familiar to those living in the U.S. Midwest.

If those storms get powerful enough, some clouds “overshoot,” or extend multiple kilometers above the troposphere and into the stratosphere—a cold, thin layer of Earth’s atmosphere beginning at about 12,000 meters (39,000 feet) above sea level.

This overshoot happens often in the United States: There are about 50,000–100,000 overshooting storms each summer, though some last only a minute or two, said Ken Bowman, an atmospheric scientist at Texas A&M University and a coauthor of the new study. 

Bowman is the lead scientist of a 6-year project called Dynamics and Chemistry of the Summer Stratosphere (DCOTSS) that is investigating these overshooting storms. 

To study overshooting storms, DCOTSS researchers use a unique aircraft called Earth Resources 2, or ER-2, which was built by NASA and flies as high as 22,860 meters (75,000 feet)—higher than 95% of the Earth’s atmosphere. Cziczo and his team used DCOTSS data from 31 May to 27 June 2022, an active fire season in the United States, for their new study. The data came from flights over the U.S. Midwest and Great Plains that specifically targeted overshooting storms. 

Their observations showed an unexpected amount of biomass-burning particles in the lower stratosphere during periods affected by overshooting clouds.

“Once we got the aircraft into the stratosphere, we just found it to be littered with these biomass-burning particles, particles from wildfires,” Cziczo said. There had been previous evidence from flights in 2002 that biomass-burning particles existed in the stratosphere, but not to this extent—Cziczo and his team found particles as high as 4 kilometers into the stratosphere, about 4 times higher than previous detection.

The new study “is really the first time people have seen a really large contribution from smoke in the lower stratosphere,” said Brian Toon, an atmospheric scientist at the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder who was not involved in the new study. 

“When you add lots of water vapor, it changes a lot of things.”

Cziczo explained that powerful storm clouds pick up smoke, either directly from burning areas or from smoke already mixed into the troposphere, then “spit” that smoke out into the stratosphere after clouds build up and cross the boundary between the two layers. Virtually all the observed biomass-burning particles were probably transported by overshooting storms, as there are no other likely mechanisms for the particles to enter the stratosphere, Bowman said.

The particles the team observed in the lower 4 kilometers of the stratosphere will likely stay suspended there for months.

The researchers didn’t have a way to track exactly where the particles they observed originated. But wildfires across the United States and Canada in the summer of 2022 were a likely source: “We just have to sort of infer that it was the smoke that was in the Midwest,” Cziczo said.

In addition to the biomass-burning particles, the overshooting storms brought a lot of moisture to the stratosphere. As the ER-2 aircraft flew through overshooting clouds, instruments on board detected additional water, sometimes taking the stratosphere’s usual 4 or 5 parts per million of water up to 20 or 30 parts per million. 

Such an influx of water can affect the chemistry, heating, and cooling of the stratosphere, but more research is needed to figure out exactly how. “When you add lots of water vapor, it changes a lot of things,” Bowman said.

Atmospheric Alterations

The combined forces of stronger storms and more wildfires could make the occurrence of these sooty particles in the stratosphere more likely as the climate continues to warm. 

Additional biomass-burning particles in the stratosphere could have consequences for Earth’s ozone layer. Particles provide additional surface area for the stratosphere’s gas molecules to stick to, encounter other gas particles, and react. Many of these reactions over time can damage the ozone layer, a shield of ozone molecules that protects Earth from too much ultraviolet radiation from the Sun.

“It’s important to make sure we understand this so that we can see what might happen in the future.”

“This is not a paper to panic about,” Bowman said. “But as the number of wildfires increases, which it’s likely to continue doing, we’ll get more biomass-burning particles in the stratosphere. And as the climate warms up, it’s likely that the amount of overshooting convection is going to increase, so that’s going to put more material into the stratosphere.”

The findings also raise numerous questions about how additional particles in the stratosphere might affect Earth’s other atmospheric processes. Additional dark, sooty particles could heat the atmosphere, which could change its dynamics or even blur the typically stark boundary between the troposphere and the stratosphere.

“It’s important to make sure we understand this so that we can see what might happen in the future,” Bowman said.

—Grace van Deelen (@gvd.bsky.social), Staff Writer

Citation: van Deelen, G. (2025), Some summer storms spit sooty particles into the stratosphere, Eos, 106, https://doi.org/10.1029/2025EO250443. Published on 26 November 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

The solar system’s oddball planet has some pretty odd moons, too. The first infrared spectra of Uranus’s small inner moons, which will be presented on 18 December at the 2025 AGU Annual Meeting in New Orleans, have shown that their surfaces are much redder, much darker, and more water-poor than the larger moons orbiting far from the planet.

“We were trying to see how these properties varied across the rings and moons,” said Matt Hedman, a planetary scientist at the University of Idaho in Moscow and a coauthor on the research. “We didn’t have a lot of information about their spectra before because they’re hard to observe.”

The new observations also revealed that some moons were not quite where they should have been, highlighting how much more astronomers have to learn about the dynamics of the Uranian system.

Small, Dark, and Red

In 1986, Voyager 2 flew past Uranus in humanity’s only visit to the system. At that time, astronomers knew only of the planet’s five major moons and a handful of rings. Voyager 2 discovered 11 more moons and was able to roughly measure their sizes. Since then, scientists have used ground- and space-based telescopes to discover more than a dozen additional satellites, bringing Uranus’s moon total to 29.

Many of the more recently discovered moons are pretty tiny, from Sycorax at 150 kilometers across to Mab and Cupid at just 10 kilometers. Most of them also orbit within or just outside Uranus’s ring system, close to the much brighter planet.

All of these properties have made it tricky for astronomers to learn more about the smallest Uranian moons. That’s where the infrared powerhouse James Webb Space Telescope (JWST) comes in.

This diagram shows the orbital distances of Uranus’s inner moons and rings, to scale. Uranus is placed at the top of the diagram. Click image for larger version. Credit: Ruslik0/Wikimedia Commons, Public Domain

“Part of what makes JWST particularly good for this compared to, say, Hubble and other optical telescopes, is that in the infrared, Uranus is much fainter, so you can see the things orbiting it way more easily,” Hedman explained. What’s more, all of the spectral features the team was interested in, like water ice, occur at wavelengths that JWST can observe.

The researchers observed Uranus at several infrared wavelengths in February and got a deep look at the inner portions of the planetary system. They wanted to characterize the known small moons and search for new ones. They did discover a previously unknown moon, temporarily named S/2025 U1, orbiting just outside the epsilon ring.

Those observations also provided the first information on the infrared brightnesses of the smallest moons, many of which have remained elusive since the Voyager flyby.

“Most of the rings and inner moons show very similar properties,” Hedman said. They tend to be much redder, darker, and more water-poor when compared with the larger outer moons Miranda, Ariel, Umbriel, Titania, and Oberon.

“And then there’s Mab,” Hedman added.

The new spectra show that Mab’s surface is bluer and more water-rich than the other inner moons, said Jacob Herman, a physics graduate student at the University of Idaho and lead author on the research. In fact, its surface spectrum looks very similar to Miranda’s, the major moon that orbits closest to the rings and to Mab. Miranda’s jigsaw surface suggests a messy history.

“There is still much to be discovered about Uranus’s small inner moons, particularly regarding their origin, composition, and long-term orbital stability.”

Did the two moons encounter each other sometime during Uranus’s chaotic past? Could that encounter be related to Uranus’s mu ring, which is likely generated by material sloughing off Mab? Hedman hopes that future observations or a long-term mission to Uranus will provide those answers.

“These new measurements significantly expand our current knowledge, revealing, for instance, striking variations in the composition and reflectivity of the surfaces of moons such as Mab, Cupid, and Perdita,” said Jadilene Xavier, an astrophysicist at São Paulo State University in Guaratinguetá, Brazil, who was not involved with this research.

“There is still much to be discovered about Uranus’s small inner moons, particularly regarding their origin, composition, and long-term orbital stability,” Xavier said. “More precise data on their density, three-dimensional shape, and surface properties would be essential to determine whether these moons are fragments produced by collisions, captured objects, or primordial remnants associated with the formation of Uranus’s ring system.”

Just a Little Bit Off

Because Voyager 2 spent only a short time visiting Uranus, it could provide only limited information about the small moons’ orbital periods and distances, sometimes with large uncertainties. When the researchers compared the moons’ current positions with the positions predicted by Voyager 2 data, some of the moons were not where they seemingly should have been.

“Perdita was quite a bit off,” Herman said. “And there’s also Cupid, which was surprising.” The positions of Cordelia, Ophelia, Cressida, and Desdemona were also off, but not by much. The team is still trying to figure out whether the differences are just a matter of having more precise observations of these tiny objects or if there are unknown dynamics in play.

“These new observations are quite useful for improving our understanding of the inner Uranian system, especially its orbital dynamics.”

“These new observations are quite useful for improving our understanding of the inner Uranian system, especially its orbital dynamics,” said Matija Ćuk, who researches solar system dynamics at the SETI Institute in Mountain View, Calif.

Ćuk, who was not involved with this research, pointed out that Cordelia and Ophelia shepherd Uranus’s epsilon ring, Cressida and Desdemona are part of a pack of moons with chaotic orbits, and Perdita is known to interact with another moon, Belinda. “So the fact that these [five] moons are not in their predicted positions is valuable for understanding the system, but I wouldn’t say it’s unexpected,” Ćuk said.

These observations hint at just how many mysteries Uranus is still hiding.

“For a dynamicist like me,” Ćuk said, “knowing the precise masses of these moons would be ideal, because then we could predict their future interactions and also estimate with some confidence how stable they are on long timescales.”

Hedman and their team plan to observe the Uranian system again with JWST, are looking through archived and technical images, and hope to establish long-term monitoring to better understand the moons’ dynamics and possibly estimate their masses. The researchers are also leaning on their colleagues who simulate planetary orbits to better understand how Uranus’s moons and rings might be influencing each other.

“It’s a very dynamic and interconnected system,” Herman said.

—Kimberly M. S. Cartier (@astrokimcartier.bsky.social), Staff Writer

Citation: Cartier, K. M. S. (2025), Uranus’s small moons are dark, red, and water-poor, Eos, 106, https://doi.org/10.1029/2025EO250442. Published on 25 November 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

The rapid retreat of glaciers, an increasingly common phenomenon, could potentially lead to complex changes in ocean chemistry. A new study has revealed that sediment runoff from retreating glaciers is less nutritious for marine life than meltwater from stable glaciers. This finding has important implications for high-latitude marine ecosystems, such as the Gulf of Alaska, where trace metals like iron and manganese are essential for supporting microorganisms at the base of the food web.

Glacial runoff, which carries sediments produced by the relentless grinding of ice on the bedrock below, is an important source of trace metal micronutrients in the ocean. These nutrients, in turn, are essential for phytoplankton growth, which sustains the marine food web and plays a major role in absorbing atmospheric carbon dioxide.

Intrigued by the effects of climate change on nutrient availability, a team of researchers used two adjacent glaciers on Alaska’s Kenai Peninsula as a natural laboratory. One of them, Aialik Glacier, is stable and terminates on the sea, while the other, Northwestern Glacier, has retreated inland approximately 15 kilometers (9.3 miles) since 1950. Because both glaciers erode the same bedrock, the researchers knew the source material for their sediments would be nearly identical.

In late May 2022, as seasonal melting intensified, the team—led by marine chemist Kiefer Forsch, who conducted the research as a postdoctoral fellow at Scripps Institution of Oceanography and is now at the University of Southern California—collected samples from the fjords of both glaciers. Working from a small aluminum boat provided by Kenai Fjords National Park, they sampled and analyzed surface water, suspended sediments, and iceberg material, looking to analyze the concentration and bioavailability of metals like iron and manganese, as well as macronutrients such as phosphorus. (Bioavailability describes the proportion of nutrients that is readily usable by marine organisms.)

The analysis revealed important differences in the proportion of bioavailable metals in the sediment plumes. Sediments from the stable Aialik Glacier were substantially richer, with approximately 18% of the iron and 26% of the manganese in bioavailable forms. In contrast, the retreating Northwestern Glacier’s sediments contained only 13% bioavailable iron and 14%–15% bioavailable manganese. The researchers described their findings in Nature Communications.

Stale Nutrients

Researchers think this drop in bioavailable nutrients may be caused by the time lapse between when the sediments were produced and when they were released into the ocean. In the stable Aialik Glacier, which ends directly in the fjord, the sediments have a very short trip from the point of erosion to the ocean. This short distance results in fresh and labile—reactive—nutrients that microorganisms can readily use.

“The impact it could have on the ecology downstream might be muted quite a bit by its lower bioavailability.”

The retreating Northwestern Glacier’s erosive action has moved far inland. As its sediments are transported to the ocean by fluvial waters, they are chemically altered, transformed into less reactive compounds. By the time the runoff reaches the fjord, Forsch said, “it’s lost a lot of its nutritious value just by sitting there, chemically weathering.”

But that’s not the whole story. In absolute terms, the amount of bioavailable metals was similar in both fjords because the overall volume of sediment in the retreating glacier’s fjord was higher. Even if the runoff was less nutritious, researchers concluded, there seemed to be more of it.

Regardless, “the impact it could have on the ecology downstream might be muted quite a bit by its lower bioavailability,” Forsch said.

The Coast Is Not the Ocean

The implications for nutrient availability extend beyond trace metals. Glaciers that terminate in the ocean, called tidewater glaciers, provide an extra benefit by inducing powerful upwelling currents. Meltwater enters the ocean at depth and quickly rises, bringing with it deep ocean water loaded with macronutrients like nitrogen and phosphorus. Phytoplankton near the ocean surface consume these nutrients and can themselves become bioavailable to the fjord’s primary consumers like zooplankton and krill. This upwelling mechanism is what makes these fjords highly productive ecosystems.

“Losing this macronutrient supply [as tidewater glaciers retreat inland] is considered the more devastating impact for coastal ecosystems,” said Jon Hawkings, a glacial biogeochemist at the University of Pennsylvania. “There’s much more iron and manganese in these fjords than there is in the ocean by orders of magnitude; they’re limited by nitrogen mainly.”

“Once the upwelling mechanism is lost, the fjord starts to become less productive,” Forsch added.

Making things worse, when a glacier retreats onto land, its sediments are ultimately delivered at the ocean surface, creating a plume that blocks light, further inhibiting phytoplankton growth. In terms of the geochemistry and biology of these ecosystems, “it’s not really a dial, it’s a switch that occurs when a glacier retreats onto land,” he said.

While the loss of tidewater glaciers will likely lead to reduced productivity within fjords, the implications for the wider ocean are different. The Gulf of Alaska is home to very important fisheries, but its overall productivity is limited by micronutrients like iron, rather than macronutrients such as nitrogen and phosphorus. Glacial retreat might accelerate the delivery of more dissolved iron and manganese out of the fjords and onto the continental shelf, but at the same time these sediments will be less nutritious than they used to be.

In fact, Hawkings suggested, researchers might want to look “off the fjords.… This is probably where this work should go next, looking at these plumes as they exit the fjords into the Gulf of Alaska.”

The study “opens up a number of new questions,” Hawkings said, but much more research is needed to answer them. “What is the impact…for marine productivity? Is this just a one-off? Should we go back to the same place and test again? What about other places like Greenland, Alaska and Patagonia? … The jury is still out in my view.”

—Javier Barbuzano (@javibar.bsky.social), Science Writer

Citation: Barbuzano, J. (2025), Glacier runoff becomes less nutritious as glaciers retreat, Eos, 106, https://doi.org/10.1029/2025EO250431. Published on 25 November 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

This is an authorized translation of an Eos article. Esta es una traducción al español autorizada de un artículo de Eos.

Gestionar los incendios en bosques tropicales puede ser una tarea muy abrumadora: los taladores y los pirómanos comúnmente se mueven más rápido que los equipos de primera intervención, los recursos son escasos y el territorio es inmenso. En la Amazonia Brasileña, estos obstáculos aprietan a un sector ambiental que crónicamente ha recibido pocos fondos, cuyos agentes de campo enfrentan amenazas de granjeros y, cada vez más, de el crimen organizado.

En 2024, los incendios arrasaron con 30.8 millones de hectáreas en Brasil, un 79% más que en 2023. Más del 80% del área total que se quemó se encontraba dentro de la Amazonia Legal, según la plataforma de datos ambientales MapBiomas (La Amazonia Legal es una región designada por el gobierno que comprende los 9 estados que están en la cuenca del Amazonas). Debido a la escala de los incendios, en agosto de 2024, el Instituto Brasileño del Ambiente y Recursos Naturales Renovables de Brasil (IBAMA, por sus siglas en portugués) incrementó la cantidad de vigilantes a 2 227 brigadistas (bomberos), con 1 239 de ellos – más de la mitad – con base en la Amazonia Legal.

Millones de hectáreas en Acre

Acre es el estado más al oeste de Brasil, colinda con Perú y Bolivia y es parte de la Amazonia Legal. En Acre, cuatro brigadas de incendios profesionales con 68 bomberos de tiempo completo operan en tres municipalidades y un área protegida. Una brigada voluntaria también opera en la ciudad más grande, que también es la capital, Rio Branco.

Con cerca de 14 millones de hectáreas de bosque que patrullar, estos grupos apenas pueden cubrir una fracción del territorio de Acre.

Resulta que la ciencia ha sido una herramienta importante para llenar el hueco, ya que el desafío de combatir el fuego en Acre no es solo sobre la falta de grupos en el campo; también está relacionada al acceso de datos. La información ambiental de Brasil está esparcida a lo largo de varias agencias: El Instituto Nacional de Investigación Espacial (INPE, por sus siglas en portugués), agencias ambientales federales como el IBAMA y el Instituto Chico Mendes para la Conservación de la Biodiversidad, la agencia Nacional de Agua (ANA, por sus siglas en portugués), y el centro Nacional para Monitoreo y Alertas de Desastres Naturales de Brasil, así como secretarías individuales de estado, cada una trabajando con sus propias prioridades y cadencias.

Sin datos arreglados en formatos compatibles, algunos de ellos se pueden sobrelapar o contradecir. “Para saber dónde tenemos que actuar, necesitamos información calificada, tenencia de tierras, zoneamientos y puntos calientes de incendios. Sin eso, cualquier política pública para incendios o deforestación va a ser inefectiva en el Amazonas”, dijo Claudio Cavalcante, jefe del Centro para Geoprocesamiento Ambiental (CIGMA, por sus siglas en portugués), el centro geoespacial que Acre creó dentro de la Secretaría del Ambiente en 2020 para conectar la deforestación y el monitoreo de incendios con la respuesta de políticas públicas.

CIGMA ha hecho los esfuerzos de integrar los datos de todas las agencias estatales y federales de Brasil para informar a los agentes en el campo. “Hemos trabajado con estratificación de datos: deforestación [en áreas] de 1 a 5 hectáreas y luego de 10 a 50. Automatizar algunos flujos de datos ha sido un trabajo muy complejo y laborioso” añadió Cavalcante, quien formó parte de una junta con investigadores, comunicadores y expertos en políticas públicas en las oficinas centrales del CIGMA en julio.

La mirada en los datos

Toda la integración sucede en el Cuarto de Situaciones de CIGMA, donde científicos y analistas evalúan alertas de incendio en vivo, niveles de los ríos, lluvia, índices de sequía y otra cantidad de datos.

“Todos los mapas para la acción en el campo se desarrollan aquí. También preparamos los reportes y notas técnicas mensuales de la deforestación”, dijo Quelyson Souza, quien coordina el Grupo de Mando y Control Ambiental de la Secretaría Ambiental de Acre.

Quelyson Souza, quien coordina el Grupo de Comando y Control Ambiental de Acre, explica cómo las alertas de tala funcionan y cómo esos datos pueden ser integrados en las respuestas para el combate a los incendios. Crédito: Bibiana Garrido/IPAM Amazonia

El sistema de CIGMA fusiona las alertas de incendios del INPE con los datos de tenencia de tierras y zoneamiento para identificar potenciales infractores. Los datos hidrogeológicos de ANA, la agencia de agua, se actualizan cada 15 minutos y alimentan los datos de la Defensa Civil y el Departamento de Incendios del estado. Los sensores de calidad del aire detectan humo que viene de la selva dentro y fuera de los límites de Brasil.

Para el coordinador de las Operaciones de Protección Ambiental del Cuerpo de Bomberos de Acre, el Mayor Freitas Filho, los datos científicos a los que sus cuerpos tienen acceso en el campo “son esenciales para optimizar y refinar el uso de los recursos operacionales”. El departamento de incendios de Acre lidera la Operación Controlada de Incendios, la cual se enfoca en integrar los equipos de agentes militares y ambientales para combatir los incendios en la estación seca, que abarca la segunda mitad del año.

Según un informe de manejo de incendios en la selva del Amazonas publicados este mes por el Instituto de Investigación Ambiental de la Amazonia (IPAM Amazônia), Acre tiene un modelo muy efectivo para vincular datos y gobernanza que recomienda sistemas de alerta temprana e intercambio abierto de datos para que las municipalidades puedan actuar de forma rápida.

Lecciones de Acre

A pesar de los desafíos, Acre resalta como uno de los pocos estados Amazónicos donde científicos, bomberos y creadores de políticas públicas comparten un mismo cuarto.

“Es inspirador ver la evolución del Cuarto de Situación de Acre. Lo uso como un ejemplo nacional porque la acción sucede en el campo, incluso más allá de las fronteras”, dijo Liana Anderson, una investigadora de percepción remota en el INPE.

“Es mucho más difícil que nos engañen los delincuentes que quieren salirse con la suya con sus delitos medioambientales”

Mientras Brasil se prepara para albergar la COP30 (la Conferencia de Cambio Climático de las Organización de las Naciones Unidas) en Belém, científicos y tomadores de decisiones esperan que la experiencia de Acre pueda ser un ejemplo de manejo del ambiente centrado en la ciencia: las bases de datos unificadas, los paneles compartidos y la colaboración pueden convertir a la información en planeación y acción.

“Cuando tenemos una idea más clara con la información a la que tenemos acceso ahora, es mucho más difícil que nos engañen los delincuentes que quieren salirse con la suya con sus delitos medioambientales”, dijo Souza. “Es como cuando te levantas la venda de un ojo cuando estas jugando a la gallina ciega”

—Meghie Rodrigues (@meghier.bsky.social), Science Writer

Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

This translation by Anthony Ramírez-Salazar (@Anthnyy) was made possible by a partnership with Planeteando and GeoLatinas. Esta traducción fue posible gracias a una asociación con Planeteando and GeoLatinas.