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Planet satellite imagery has started to reveal the events that killed 70 people at in northern India. It clearly indicates that intense rainfall triggered landslides that transitioned into channelised debris flows.

On 5 August 2025, a series of terrifying landslides struck Dharali in Uttarkashi, Uttarakhand, northern India. I blogged about this at the time – the Wikipedia page for the disaster indicates that about 70 people were killed.

In the aftermath of the disaster, there was some very strange speculation about the cause. For example, the Times of India quotes an expert from the India Meteorological Department as follows:

“Only very light to light rain was observed in the affected area over 24 hours. The highest rainfall recorded anywhere in Uttarkashi was merely 27mm at the district headquarters.”

They quote another scientist as follows:

“This volume is insufficient to trigger floods of such severity, suggesting a powerful event such as a glacier burst or a GLOF.”

They also quote a senior geologist as follows:

“Such disasters occur when water accumulates at higher elevations and discharges suddenly … Heavy rainfall alone can’t cause such a disaster.”

This is of course a nonsense. Intense rainfall is highly spatially variable, especially in high mountains. Take a look at this “Black Rainfall” event in Hong Kong (which was not in a high mountain area, where the events are even more extreme, but Hong Kong has a fantastic rain gauge network):-

Hong Kong Observatory data showing the distribution of precipitation in a “Black rainfall” event in 2020. Credit: Hong Kong Observatory

The western and southern parts of Lantau island received less than 40 mm of rainfall that day, whilst the area around Sha Tin received over 400 mm. The distance between the boundary of >400 mm and <40 mm is a few kilometres.

Cloudburst precipitation is incredibly spatially variable, so it is not the case that a failure to record heavy rainfall on a sparse rain gauge network means that such events did not occur. And, as I have shown on numerous occasions on this blog, intense rainfall most certainly can, and does, trigger catastrophic debris flows.

However, there was a stronger piece of evidence that suggests that this event was not a glacier burst or a GLOF. On 5 August 2025, the debris flows occurred in two separate, but adjacent catchments, one at Dharali but another at Harshil, about 500 m to the west. These two catchments are not connected, but they are separated by a ridge. This would suggest a common trigger – in the absence of an earthquake, a localised rainfall event is highly likely (especially in the peak of the monsoon).

Of course, to be sure we need either fieldwork or satellite imagery. In the rainy season, this is really hard to achieve but as the monsoon withdraws this becomes possible. And sure enough, on 11 September 2025, Planet captured a fabulous satellite image that starts to reveal the story.

So let’s start with Harshil – the picture here is straightforward. The slider below shows Harshil and the lower part of the catchment using Planet imagery draped onto the Google Earth DEM. Note that the change in the topography is not captured in the DEM.

A comparison of Harshil before and after the 5 August 2025 Dharali disaster. Images by Planet, using the Google Earth DEM.

The path of the debris flow is clear, and upstream there is a very obvious large landslide. Thus, the most likely cause of the Harshil debris flow is that slope failure.

The image below shows the landslide itself, but again note that the topography in the DEM has not updated, so the morphology is distorted. But this is clearly a large rock slope failure.

I will caveat to say that at this stage we cannot definitively say that this landslide occurred on 5 August 2025, but Occam’s razor implies that this is the cause.

The landslide upstream from Harshil after the 5 August 2025 Dharali disaster. Image copyright Planet, used with permission. Image dated 11 September 2025.

This slope failure has released a huge amount of sediment into the catchment. This will cause problems for Harshil in the future.

So now let’s turn to Dharali itself. This is more complex. We have to go high up into the catchment above the village to see what’s happened. The slider below shows before and after Planet images of the upper part of the catchment above Dharali:-

Planet images showing the upper part of the catchment above Dharali before and after the 5 August 2025 disaster. Images by Planet using the Google Earth DEM.

There has been substantial change on both sides of the catchment. Let’s start with the west (the right side of the image above as the image is from the south looking towards the north):-

The west side of the upper part of the catchment above Dharali after the 5 August 2025 disaster. Image copyright Planet, used with permission. Image copyright Planet, used with permission. Image dated 11 September 2025.

The juxtaposition of the sediments lower down the valley suggests to me that this was the cause of the first (most catastrophic) debris flow at Dharali. The image strongly indicates that this was a channelised debris flow initiated by a landslide in glacial sediments in the upper part of the catchment. There was a huge amount of entrainment of channel sediments downstream. Note that there is a pre-existing, smaller, landslide at this site.

Thus, the major debris flow at Dharali was probably initiated by a shallow landslide that transitioned into a channelised debris flow.

Events on the east side of the catchment are much less clear. I suspect that the processes here generated at least some of the smaller debris flows that struck Dharali after the first event. This is the Planet image for this side of the valley:-

The east side of the upper part of the catchment above Dharali after the 5 August 2025 disaster. Image copyright Planet, used with permission. Image copyright Planet, used with permission. Image dated 11 September 2025.

The changes to the fan in the centre of the image are notable, but what caused this? I am not entirely sure. A closer comparison of the glacial sediment above this fan looks like this:-

Planet images showing the upper part of the catchment above Dharali before and after the 5 August 2025 disaster. Images by Planet using the Google Earth DEM.

In the foreground is a trough that has suffered extensive erosion. But there is also major change in the slopes above that trough. I have a suspicion that the feature that I have highlighted below might be quite significant:-

The upper eastern part of the catchment above Dharali before the 5 August 2025 disaster. Image copyright Planet, used with permission. Image dated 11 September 2025.

It appears to me that a landslide has occurred on this area of glacial sediment. Did this generate one or more channelised debris flows? There are other changes too – so maybe there were repeated shallow failures that generated the smaller debris flows observed at Dharali?

In conclusion, we can say:

1. The Dharali disaster was caused by rainfall. There is no other credible trigger that explains simultaneous events in two separate, adjacent, catchments.
2. Given the rain gauge record, this must have been a highly localised, cloudburst event.
3. Harshil was destroyed by a debris flow that probably originated from a rock slope failure in the catchment above the village.
4. The first Dharali debris flow was probably triggered by a rainfall triggered shallow landslide in glacial deposits in the upper part of the catchment, which transitioned into a channelised debris flow.
5. The subsequent debris flows at Dharali were caused by other erosive events in these glacial tills. The origin is not entirely clear, but there is evidence of at least one further shallow landslide that may have been the origin for one or more events.

This is a very provisional analysis based on lower resolution (but still brilliant) imagery. These hypotheses need to be explored through fieldwork and/or high resolution imagery.

Finally, it is absolutely inevitable that the fans at Dharali and Harshil will suffer similar events in the future. Neither will be safe for habitation.

Reference and acknowledgement

Thanks to loyal reader Jack for really interesting and stimulating discussions about these events. And special thanks to Planet for the astonishing imagery.

Planet Team (2025). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/

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Astronomers have recently found that roughly a third of planet-forming disks around young Sun-like stars are tilted relative to the direction that their star spins.

“All young stars start out with a disk. But the relative orientation between the disk and the star’s spin axis, little was known about that,” explained lead researcher Lauren Biddle, a planetary scientist at the University of Texas at Austin.

This discovery, published in Nature, could help answer the long-standing question of how planets come to orbit their stars at wonky angles: Maybe they were born that way.

Skewed from the Start

There’s a universal truth that when a new star collapses out of a cloud of gas, angular momentum must be conserved. That means that as the nebulous star shrinks in size, it also rotates faster, like when a spinning ice skater draws their arms in and speeds up. The surrounding leftover gas and dust flatten out into a disk that spins in the same direction as the star, and that disk may eventually form planets that spin and orbit in that same direction.

But the universe is rarely so neat and tidy.

Of the thousands of known exoplanets, dozens of them orbit at wonky angles relative to their star’s spin axis. In our own solar system, the plane in which the eight planets orbit is tilted by about 6º from the Sun’s spin axis. Astronomers have theorized that some of these misalignments, or obliquities, result from dynamical events that take place after a planetary system has already formed: A star passes by and disturbs the orbits, or a major collision knocks a planet off course.

Some of those misalignments, however, are baked in from the start. Previous studies have attempted to observe young star systems and their planet-forming disks to see whether those disks start out tilted or aligned. But those studies were limited by the fact that not many protoplanetary disks had yet been discovered, and many of those that were known were part of binary star systems, Biddle explained. Although those studies found some tilted disks, the gravity from the binary star, rather than an intrinsic misalignment, may have been the culprit.

“If systems begin with primordially tilted orbits, then there is no need to invoke other mechanisms—many of which would destabilize neighboring planets—within those systems,” said Malena Rice, a planetary astrophysicist at Yale University in New Haven, Conn. “By understanding the range of primordial tilts and comparing that distribution with more evolved systems, we can piece together the evolutionary sequences of different classes of planetary systems.” Rice was not involved with this study.

“The one-third rate of misalignment stands independent of everything else.”

Biddle and her colleagues compiled a new sample of young star systems by combining observations of protoplanetary disks from the Atacama Large Millimeter/submillimeter Array (ALMA) and measurements of stars’ spin from the Transiting Exoplanet Survey Satellite (TESS) and retired K2 mission. Biddle explained that because ALMA, TESS, and K2 have released such large datasets, her team could curate their sample to look only at Sun-like stars that did not have any binary companions.

They found that 16 of the 49 stars in their sample (about a third) had protoplanetary disks with obliquities of at least 10°, the lower limit of what they could measure. The remaining two thirds of the systems showed no significant evidence of misalignment. This rate of high-obliquity disks is consistent with past studies but more than doubles the number of young, single, Sun-like stars for which astronomers know the degree of disk misalignment.

The 16 stars that host tilted disks did not share any obvious characteristics like mass, temperature, and size, and the disks themselves also had different sizes, masses, and structures.

“We didn’t find any correlation there,” Biddle said. “At this point, independent of other system parameters, the one-third rate of misalignment stands independent of everything else.”

Oblique Across Space and Time

Past studies have suggested that moderate disk obliquities might rise from imperfections in the nebulous cloud that formed the star system: An odd clump in the right spot might create turbulence that grows stronger as the cloud collapses, or the clump might fall onto the disk late and tip it off its axis.

“Moderate misalignments of a few tens of degrees can be produced naturally by either turbulence in the natal molecular cloud, late-stage disk accretion, or some combination of the two,” Rice said.

However, that doesn’t necessarily mean that every misaligned exoplanet, or even a third of them, started out that way.

“It would be great to take a crack at mapping stellar obliquities across space and time.”

“A misalignment between a planet’s orbital plane and its host star’s spin axis can originate in two broad phases: during the star and planet formation stage…[and] later, during the system’s main sequence lifetime,” explained Simon Albrecht, an astronomer at Aarhus University in Denmark who was not involved with this research. “If we can determine the fraction of systems that are already misaligned right after birth, that helps us distinguish between these two broad possibilities.”

Determining how much of a system’s tilt comes early or late and whether that tilt changes over a planetary system’s lifetime will require observing a lot more misaligned planetary systems at all stages of evolution, Biddle said. She added that the upcoming data release from the now-retired Gaia mission will be key to answering both of those questions.

“It would be great to take a crack at mapping stellar obliquities across space and time,” Biddle said. “Being able to fill in that time parameter space will help quantify how important dynamics is for generating that final [obliquity] distribution that we observe in planetary systems.”

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

This news article is included in our ENGAGE resource for educators seeking science news for their classroom lessons. Browse all ENGAGE articles, and share with your fellow educators how you integrated the article into an activity in the comments section below.

Citation: Cartier, K. M. S. (2025), Tilted planet system? Maybe it was born that way, Eos, 106, https://doi.org/10.1029/2025EO250338. Published on 17 September 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: AGU Advances

To help project Earth’s future climate, it is critical to understand how the capacity of ecosystems to take up and store carbon is changing as atmospheric carbon dioxide levels rise and climate change intensifies.

Bilir et al. [2025] integrate satellite data with a model of terrestrial carbon cycling to parse regionally-specific influences of CO2 and climate on carbon storage in living and dead plant material, and the associated residence time of carbon in those pools.

For the specified regions, changes in total carbon storage (left Y axis, solid bars) and percent change in mean residence time of carbon (right Y axis, hatched bars) that can be attributed to atmospheric CO2 (top panel), climate trends (middle panel), and the combined, interacting effects of CO2 and climate (bottom panel). Credit: Bilir et al. [2025], Figure 6

Their work helps untangle the mechanisms driving what they and others have observed: that CO2 increases carbon storage more than climate effects decrease it. They find greater carbon storage in living plants globally and a shift in dead carbon storage from mid- and high latitudes to the tropics. They also demonstrate a reduction in mean carbon residence times across all latitudes. The shift in carbon storage from dead to live pools underscores the sensitivity of terrestrially-mediated carbon cycling and residence times to living plant carbon uptake and storage potentials.

These efforts help us understand, at a global scale, how rising atmospheric CO2 and climate change interact to prompt a latitudinally-specific reorganization of our planet’s terrestrial carbon cycling, and thus its climate.

Citation: Bilir, T. E., Bloom, A. A., Konings, A. G., Liu, J., Parazoo, N. C., Quetin, G. R., et al. (2025). Satellite-constrained reanalysis reveals CO2 versus climate process compensation across the global land carbon sink. AGU Advances, 6, e2025AV001689. https://doi.org/10.1029/2025AV001689

—Sharon Billings, Editor, AGU Advances

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Climate change caused 16,469 deaths in European cities this summer, new research estimates.

This summer was the fourth hottest in European history, and its effects on the continent’s population have been widely reported. Spain experienced its most intense heat wave in history in August 2025. Türkiye saw its highest recorded temperature ever (50.5°C, or 122.9°F). Finland saw an “unprecedented” three straight weeks of 30°C heat.

A new, rapid-analysis study by researchers at Imperial College London (ICL) and the London School of Hygiene & Tropical Medicine estimated that 24,400 people across 854 European cities and urban centers died from heat-related causes between June and August 2025. Using climate models and a comparison of this figure with how many heat-related deaths would have occurred in a 1.3°C cooler world, the researchers estimated that climate change was responsible for 68% of these deaths.

“These numbers represent real people who have lost their lives in the last months due to extreme heat.”

“In other words, it could have tripled the death toll,” said Garyfallos Konstantinoudis, a biostatistician at ICL’s Grantham Institute – Climate Change and the Environment.

Though the planet has warmed about 1.3°C overall since preindustrial times, Europe is warming more quickly than the rest of the planet, meaning that temperatures on the continent this summer were about 1.5°C to 2.9°C warmer than they would have been without anthropogenic warming.

In a Tuesday press conference, the researchers explained that their estimate of 16,649 climate-related deaths is likely conservative, in part because climate models are known to underestimate warming in Europe. In addition, their estimate includes only deaths in urban centers with populations above 50,000 people—areas that represent only about 30% of Europe’s population. They focused on these urban areas because these locations had greater data availability, but that means the estimate is just a snapshot.

“These numbers represent real people who have lost their lives in the last months due to extreme heat,” said Friederike Otto, a climatologist at ICL’s Centre for Environmental Policy. “Many of these would not have died if it wasn’t for climate change. And if we continue on the path that we are on now, continue burning fossil fuels, these deaths will only increase.”

The Hidden Costs of Heat

The study also notes that northern Europe experienced a higher proportion of heat-related deaths than southern Europe, despite southern Europe enduring higher heat (some cities in the region have warmed by up to 3.6°C) and more excess mortality overall. The reason is that prior to climate change, heat in northern Europe rarely reached levels that affected human health at all. Now, explained Konstantinoudis, “almost all of the heat-related deaths in northern Europe…are due to climate change.”

“Reducing fossil fuel use is one of the most important public health interventions of our time.”

Courtney Howard, vice-chair of the Global Climate and Health Alliance and an emergency physician in Canada’s Yellowknives Dene Territory, who was not involved in the study, noted that extreme heat can raise the risk of deadly heart attacks and strokes because high heat causes the heart to work harder. It can also fatally worsen respiratory conditions such as asthma because ozone pollution tends to increase during extreme heat events. Thus, many of the deaths that occur during heat waves are not necessarily recorded as heat deaths.

“The result is that heat numbers capture only a small fraction of the real story at the bedside,” she said. “Experts do not believe that we can adapt health systems adequately to cope with the temperatures that we are currently facing. That’s why reducing fossil fuel use is one of the most important public health interventions of our time.”

To estimate heat deaths, researchers turned to an existing dataset that showed relationships between temperature and mortality across the 854 urban areas used in the study. They then estimated the number of daily deaths during the heat wave using historical Eurostat data and information on which days exceeded minimum mortality temperature.

It’s Not Just Europe Click image for larger version. Credit: Imperial Grantham Institute

Among the countries included in the study, the Baltic nations of Estonia, Latvia, and Lithuania were the only three that did not experience hotter-than-usual summers.

Rome, Athens, and Bucharest saw the highest heat-related death rates per capita among European capital cities, the study found. In general, cities are hotter than surrounding areas because of the urban heat island effect, in which concrete surfaces trap heat and raise city temperatures.

Chris Callahan, a climate scientist at Indiana University Bloomington who was not involved in the study, said that though the study is not peer reviewed, its methods appear to be “standard and based on extensive peer-reviewed research.”

The researchers noted several factors their study did not consider, including cities’ efforts to adapt to climate change and all adverse health effects of heat. It also did not capture changes to baseline populations that occurred post-COVID-19, which might have led to higher numbers for some cities.

“The findings in this study are stark and concerning, as they illustrate that climate change is already the dominant influence on heat-related mortality in Europe,” Callahan told Eos in an email.

“We are warming the world through our fossil fuel emissions and other activities and that…is causing people to die.”

Europe faces particularly high risks related to climate change, he added, both because temperatures are rising more quickly in western Europe than in other parts of the world and because Europe’s aging population is highly vulnerable to heat. In fact, this study found that people over 64 made up 85% of the climate-related deaths in European cities this summer.

However, the study authors noted that the growing toll warming is taking on human health is not unique to Europe.

“The specifics will vary wherever you’re looking in the world, but the basic point of these studies will always be the same: that we are warming the world through our fossil fuel emissions and other activities and that this is causing people to die,” said Clair Barnes, a statistician at ICL’s Centre for Environmental Policy.

—Emily Gardner (@emfurd.bsky.social), Associate Editor

Citation: Gardner, E. (2025), Climate change may have killed 16,469 people in Europe this summer, Eos, 106, https://doi.org/10.1029/2025EO250348. Published on 17 September 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.

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.

Misunderstandings and disinformation abounded at a 16 September hearing of the Subcommittee on Delivering on Government Efficiency about geoengineering, which encompasses efforts to alter Earth systems for the purpose of mitigating climate change. 

Rep. Marjorie Taylor Greene (R-GA), chairwoman of the subcommittee, called for an outright ban on geoengineering and used the hearing to promote her Clear Skies Act, which would impose fines of up to $100,000 and potentially jail time for anyone conducting “weather modification” activities.

Geoengineering is an amorphous term that can refer to a range of climate intervention activities, including cloud seeding to spur precipitation, management of solar radiation to cool Earth by reflecting sunlight, and carbon capture and sequestration efforts.

“Today’s advocates of geoengineering don’t just want to address droughts or improve conditions for agriculture” Greene said. “They want to control the Earth’s climate to address the fake climate change hoax and head off global warming. That, of course, requires massive interventions.”

In addition to asserting that climate change is a hoax, Greene implied that climate interventions could remove enough carbon dioxide from the atmosphere to harm plant life. In questioning, Rep. Brian Jack (R-GA) repeated a dubious claim that the release of dry ice into a hurricane in 1947 in an experiment called Project Cirrus caused the hurricane to turn toward Georgia. And Rep. Pat Fallon (R-TX) argued that former Vice President Al Gore’s misrepresentation regarding the melting of the north polar ice cap invalidates decades of climate science. 

One witness during the hearing was Christopher Martz, a policy analyst and meteorologist at the Committee for a Constructive Tomorrow, an environmental policy think tank that has cast doubts on climate science. Martz received an undergraduate degree in meteorology in May and runs a weather blog that questions the influence of climate change in extreme weather events. 

 
Related

•  Marjorie Taylor Green Introduces ‘Weather Modification’ Ban
•  Watch the hearing: Playing God with the Weather — A Disastrous Forecast
•  AGU’s Ethical Framework Principles for Climate Intervention Research
•  Get Involved: AGU Science Policy Action Center
 

Martz asserted that the science behind climate change is uncertain, and therefore that climate intervention is an alarmist reaction: “Warming could be mostly natural and we just don’t know,” he said. It’s not: The vast majority of scientists agree that Earth is warming and human activities are to blame.

The hearing’s only climate scientist witness, former Lawrence Livermore National Laboratory scientist Michael MacCracken, tried to combat the climate denialism in the room. He challenged the ideas that current climate intervention efforts are sufficiently powerful or scalable enough to change a major weather phenomenon, or that they are targeted to harm the public.

Despite the falsehoods raised by Greene and others at the hearing, some of their comments aligned with how many scientists view climate intervention—as a potentially risky endeavor that requires more research before it is considered viable and safe.

AGU’s own Ethical Framework Principles for Climate Intervention Research, developed with the contributions of scientists, policymakers, ethicists, government agencies, nongovernmental organizations, and potentially impacted communities, acknowledges this perspective: “Substantial research and evaluation efforts will be required to determine the effectiveness, risks, and opportunities of climate intervention,” the framework states.

At the hearing, Greene asked “who would control the dial” if scientists managed to reliably alter Earth’s climate.

Such questions are a reason to lean into Earth systems research, said Roger Pielke, Jr., a political scientist at the conservative American Enterprise Institute who spoke at the hearing. Pielke called for Congress to enact legislation to improve oversight of geoengineering and recommended that Congress ask the National Academy of Sciences to assess what scientists do and don’t know about the effects of climate intervention activities.

Rep. Melanie Stansbury (D-NM), ranking member of the subcommittee, closed the hearing with a plea to support science. “Literally all we’re trying to accomplish by climate action is to keep our planet in some sort of balance,” she said, calling the Trump administration’s firing of federal scientists and engineers, the defunding of science agencies, the firing of the EPA science panel, and the deregulation of carbon emissions “dangerous.”

Stansbury and Greene agreed on one thing: “We have one Earth,” they each said.

—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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After a tropical cyclone passes through an area, governments take stock of the damage. NOAA, for instance, lists the costs associated with damaged buildings and roads and reports any injuries or deaths attributed to the storm.

“This research supports the historically overlooked indirect health risk and burden of tropical cyclones.”

However, research suggests that storms can also have hidden, long-term consequences for human health. In a new study published in Science Advances, scientists report that cyclones, also known as hurricanes and typhoons, produce a significant uptick in hospitalizations due to cardiovascular disease for months after they subside. In addition, the potential populations at risk for such hospitalizations are growing as a result of climate change intensifying cyclones and driving them into temperate regions such as Canada and New Zealand.

“This research supports the historically overlooked indirect health risk and burden of tropical cyclones and suggests the need for extending public health interventions and disaster preparedness beyond the immediate cyclone aftermath,” said Wenzhong Huang, an environmental epidemiologist at Monash University in Australia and the lead author of the new study.

Heart Problems Spike After Storms

Previous studies have examined possible connections between cardiovascular disease and cyclones, but most have focused on a single health center and storm in the United States.

“For our study, we encompassed multiple tropical cyclone events across decades and across multiple countries and territories with diverse socioeconomic contexts,” Huang said. “We also analyzed much longer post cyclone periods.”

“I didn’t expect that the risk would persist that long.”

The researchers tracked cardiovascular disease–related hospitalizations of more than 6.5 million people across Canada, New Zealand, South Korea, Taiwan, Thailand, and Vietnam from 2000 to 2019. They identified 179 locations that experienced cyclones and documented how many days storms hit each area. The team then examined hospital records to see whether more people were admitted for heart problems after cyclones, tracking patients for up to a year after each storm.

The results revealed that hospitalizations associated with heart health jumped 13% for every additional day a location was hit by a cyclone. The biggest spike in hospitalizations didn’t occur immediately after the cyclones but, rather, came 2 months after they passed, and the increased risk of hospitalizations didn’t subside until 6 months later.

“I didn’t expect that the risk would persist that long,” Huang said.

The health burden also fell unevenly across populations. Men, people in their 20s through 50s, and those in disadvantaged communities had the highest risk. In fact, cardiovascular risks after cyclones fell during the study period in wealthier areas while rising in poorer areas. This result suggests that improved health care access and disaster preparedness have benefited only some populations, with Thailand and Vietnam seeing the most cyclone-related heart problems. In total, strokes and ischemic heart disease (in which blood vessels supplying the heart are narrowed) were the most common maladies reported.

“There is not a single disease that’s not touched upon by hurricanes.”

Naresh Kumar, an environmental health scientist at the University of Miami who studies the health effects of cyclones but was not involved in the new study, was not surprised by the findings. According to his own extensive research on hurricanes in Florida and Puerto Rico, “there is not a single disease that’s not touched upon by hurricanes,” Kumar said.

But he would have liked the authors of the new study to narrow down the mechanisms driving up cardiovascular health risk after cyclones. The possible causes are abundant. In the months following a cyclone, people increase their use of generators, which produce pollutants; eat more calorie-dense canned foods; can’t exercise or access prescription medicines as easily; and are under immense psychological stress—all of which can increase the risk of cardiovascular disease. Meanwhile, regular health care services are often disrupted, so preventative care is limited.

Understanding these mechanisms is critical because current disaster response systems vastly underestimate the health burden of tropical storms, researchers say. “We are still scratching the surface in terms of characterizing the health effects of hurricanes,” Kumar said.

Huang said untangling the most significant contributors to increased risk following a cyclone is the next phase of his research. “I want to understand and investigate the candidates underlying this risk pattern,” he said.

As part of this process, Huang also aims to identify the reasons behind the elevated risk in some populations, such as working-age men. The research could help public health officials target interventions to high-risk populations and monitor cardiovascular health in the months following cyclones.

The Worsening Exposure to Storms

Answering the question of why more people suffer from heart problems after cyclones is becoming increasingly important to policymakers as more communities come under threat. Warmer oceans are fueling more intense storms with higher wind speeds and longer durations, while rising sea levels worsen storm surge flooding that can prolong recovery.

Climate change is also pushing tropical cyclones poleward into regions that have historically experienced few severe storms, such as eastern Canada and New Zealand. “Places that historically experienced fewer cyclone events could have much higher risk,” Huang said, suggesting such regions may be inadequately equipped to respond to major storms. “We need to focus on these regions to better prepare for the growing risk.”

—Andrew Chapman (@andrewchapman.bsky.social), Science Writer

Citation: Chapman, A. (2025), Cyclones affect heart health for months after they subside, Eos, 106, https://doi.org/10.1029/2025EO250342. Published on 16 September 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.

It’s been nearly 2 centuries since a planet was discovered in the solar system. But now scientists think they’ve uncovered evidence of a newcomer that just might usurp that honor from Neptune. Following an analysis of the orbits of bodies in the Kuiper Belt, a team has proposed that an unseen planet at least 25 times more massive than Pluto might reside there. These results were published in Monthly Notices of the Royal Astronomical Society.

The Kuiper Belt is loosely defined as a doughnut-shaped swath of space beginning just beyond the orbit of Neptune and extending to roughly 1,000 times the Earth-Sun distance. It’s home to untold numbers of icy, rocky objects, including Pluto and other so-called Kuiper Belt objects such as Arrokoth.

Everything in the Kuiper Belt can be thought of as cosmic debris, said Amir Siraj, an astrophysicist at Princeton University and lead author of the new paper. “It represents some of the leftovers from the formation of our solar system.”

And most of those leftovers are small: Pluto is the most massive known Kuiper Belt object, and it’s just 0.2% the mass of Earth.

But over the past decade, scientists have hypothesized that something substantially larger than Pluto might be lurking in the Kuiper Belt. Evidence of that unseen world—a so-called Planet Nine or Planet X—lies in the fact that six Kuiper Belt objects share curiously similar orbital parameters and are associated in physical space. A nearby, larger planet could have shepherded those worlds into alignment, researchers have proposed.

Planes, Planes, Everywhere

Siraj and his colleagues recently took a different tack to look for a massive resident of the Kuiper Belt: They analyzed a much larger sample of Kuiper Belt objects and focused on their orbital planes. One would naively expect the average orbital plane of Kuiper Belt objects to be the same as the average orbital plane of the planets in the solar system, said Siraj. But a planet-mass body in the Kuiper Belt would exert a strong enough gravitational tug on its neighboring Kuiper Belt objects to measurably alter the average orbital plane of the Kuiper Belt, at least in the vicinity of the planet. Siraj and his collaborators set out to see whether they could spot such a signal.

“Neptune has a really strong grasp on the outer solar system.”

The researchers extracted information about the orbits of more than 150 Kuiper Belt objects from the JPL Small-Body Database managed by NASA’s Jet Propulsion Laboratory in Pasadena, Calif. Of the several thousand known Kuiper Belt objects, the team honed in on that subset because those objects aren’t gravitationally influenced by Neptune. Neptune is the playground bully of the outer solar system, and the orbits of many Kuiper Belt objects are believed to be literally shoved around by gravitational interactions with the ice giant. “Neptune has a really strong grasp on the outer solar system,” said Siraj.

The team calculated the average orbital plane of their sample of Kuiper Belt objects. At distances of 50 to 80 times the Earth-Sun distance, they recovered a plane consistent with that of the inner solar system. But farther out, at distances between 80 and 200 times the Earth-Sun distance, the researchers found that their sample of Kuiper Belt objects formed a plane that was warped relative to that of the inner solar system. There was only a roughly 4% probability that that signal was spurious, they calculated.

Meet Planet Y

Siraj and his collaborators then modeled how planets of different masses at various orbital distances from the Sun would affect a simulated set of Kuiper Belt objects. “We tried all sorts of planets,” said Siraj.

By comparing those model results with the observational data, the researchers deduced that a planet 25–450 times more massive than Pluto with a semimajor axis in the range of 100–200 times the Earth-Sun distance was the most likely culprit. There’s a fair bit of uncertainty in those numbers, but the team’s results make sense, said Kat Volk, a planetary scientist at the Planetary Science Institute in Tucson, Ariz., not involved in the research. “They did a pretty good job of bracketing what kind of object could be causing this signal.”

To differentiate their putative planet from Planet X, Siraj and his colleagues suggested a new name: Planet Y. It’s important to note that these two worlds, if they even exist, aren’t one and the same, said Siraj. “Planet X refers to a distant, high-mass planet, while Planet Y denotes a closer-in, lower-mass planet.”

“This is really expected to be a game changer for research on the outer solar system.”

There’s hope that Planet Y will soon get its close-up. The Legacy Survey of Space and Time (LSST)—a 10-year survey of the night sky that will be conducted by the Vera C. Rubin Observatory in Chile beginning as soon as this fall—will be supremely good at detecting Kuiper Belt objects, said Volk, who is a member of the LSST Solar System Science Collaboration. “We’re going to be increasing the number of known objects by something like a factor of 5–10.”

It’s entirely possible that Planet Y itself could be spotted, said Volk. But even if it isn’t, simply observing so many more Kuiper Belt objects will better reveal the average orbital plane of the Kuiper Belt. That will, in turn, shed light on whether it’s necessary to invoke Planet Y at all.

Even if his team’s hypothesis is proven wrong, Siraj says he’s looking forward to the start of the LSST and its firehose of astronomical data. “This is really expected to be a game changer for research on the outer solar system.”

—Katherine Kornei (@KatherineKornei), Science Writer

Citation: Kornei, K. (2025), A survey of the Kuiper Belt hints at an unseen planet, Eos, 106, https://doi.org/10.1029/2025EO250344. Published on 16 September 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.

Gale Sinatra y su esposo huyeron de su casa en Altadena, California, el 7 de enero con poco más que sus maletas, llevándose solo uno de sus dos autos.

“Pensábamos que íbamos a estar fuera por esa noche”, dijo Sinatra. “Pensábamos que controlarían el incendio y que volveríamos a entrar”.

Cuando la pareja regresó, semanas después, fue para excavar entre los escombros de su antigua casa, quemada por el incendio de Eaton.

Aunque escaparon con vida, los riesgos para la salud no fueron la excepción para Sinatra, su esposo (quien prefirió no ser identificado para esta historia) y otros vecinos. Los incendios de Eaton y el cercano Palisades llenaron la cuenca de Los Ángeles con una neblina tóxica durante días, y las labores de limpieza amenazaron con levantar partículas carbonizadas mucho después de que los incendios se extinguieran.

Equipos de científicos de todo el país, junto con miembros de la comunidad, monitorearon la calidad del aire en las semanas posteriores al incendio, buscando aprender más sobre los riesgos asociados a la salud respiratoria e informar a la comunidad sobre cómo protegerse.

Incendios urbanos versus incendios forestales

Inhalar humo de cualquier incendio puede ser perjudicial. El humo contiene componentes peligrosos, como compuestos orgánicos volátiles (COV) emitidos por la quema de vegetación y productos tales como pintura y productos de limpieza; y material particulado, como polvo y hollín.

Aproximadamente el 90 % del material particulado (PM) presente en el humo de los incendios forestales son las PM2.5, o partículas de menos de 2.5 micrómetros de diámetro, lo suficientemente pequeñas como para penetrar en el torrente sanguíneo y en las zonas profundas de los pulmones.

Michael Kleeman utiliza estos instrumentos para monitorear la calidad del aire desde la parte trasera de un vehículo en Victory Park, Altadena, lo más al norte posible sin entrar en la zona de evacuación. Crédito: Michael Kleeman

Los incendios forestales urbanos presentan sus propios peligros, ya que no solo queman árboles y otra vegetación, sino también viviendas e infraestructura.

Cuando Sinatra regresó a su antiguo hogar, quedó impactada por todo lo que el fuego había quemado, desde sus joyas hasta su coche. “Se me hizo muy inquietante estar en la cocina y de repente decir: ¿Dónde está mi refrigerador?”, comentó. “¿Cómo derrites totalmente refrigerador?”

En enero de 2025, los incendios de Palisades y Eaton devastaron más de 150 kilómetros cuadrados en ciudades y zonas forestales del condado de Los Ángeles. A pesar de verse afectados personalmente, los científicos del área de Los Ángeles trabajaron diligentemente para comprender cómo los incendios en la interfaz entre lo urbano y lo forestal crean peligros únicos a través del aire, la tierra y el agua.

En el futuro, las condiciones cálidas y secas, agravadas por el cambio climático, seguirán aumentando el riesgo de incendios como estos. El trabajo de estos científicos puede proporcionar un modelo para la evaluación rápida de riesgos, la mitigación de riesgos para la salud y la planificación urbana en otras comunidades propensas a incendios”.

“Desde colchones hasta alfombras, pintura y aparatos electrónicos, todo se quema”, afirmó Roya Bahreini, científica ambiental de la Universidad de California, Riverside (UCR). Bahreini también es coinvestigadora principal de la Red de Medición de la Química y la Ciencia Atmosférica (ASCENT, por sus siglas en inglés), un proyecto de monitoreo de la calidad del aire a largo plazo liderado por el Instituto de Tecnología de Georgia, UCR, y la Universidad de California, Davis (UC Davis).

ASCENT, que se lanzó en 2021, cuenta con estaciones en todo el país, incluyendo tres en el sur de California. Durante los incendios de enero en Los Ángeles, que arrasaron no solo Altadena (una comunidad no incorporada del interior) sino también barrios costeros, estas estaciones detectaron niveles de plomo, cloro y bromo en órdenes de magnitud superiores a lo habitual.

Las casas antiguas a veces tienen pintura con plomo, techos de asbesto o terrazas y cercas de madera tratadas con conservantes que contienen arsénico. Las tuberías de PVC contienen cloro. Y los retardantes de llama a menudo contienen compuestos orgánicos bromados. En estas formas, estos materiales no necesariamente representan un alto riesgo para la salud humana. Sin embargo, al quemarse y liberarse al aire, pueden ser peligrosos.

Las columnas de humo del incendio de Palisades (izquierda) y del incendio de Eaton se observan desde el espacio el 9 de enero. Crédito: ESA, contiene datos modificados de Copernicus Sentinel, CC BY-SA 3.0 IGO

Michael Kleeman, ingeniero civil y ambiental de la Universidad de California en Davis, explicó que la mortalidad a corto plazo asociada con eventos con altos niveles de PM2.5, como los incendios forestales, suele manifestarse en forma de un infarto cardíaco. Sin embargo, inhalar el humo de los incendios forestales urbanos o las partículas que se levantan del polvo y las cenizas durante las labores de remediación puede presentar riesgos que no son evidentes de inmediato. “No se trata de un infarto inmediato, al día siguiente o a los tres días de la exposición. Se trata de un riesgo de cáncer que aparece mucho más adelante”, señaló Kleeman. “[El riesgo a] la exposición a lago plazo puede tener un efecto insidioso”.

Mapas de calidad del aire

“[El riesgo a] la exposición a lago plazo puede tener un efecto insidioso”.

El sur de California no es ajeno a los incendios forestales (tampoco Sinatra, quien ha evacuado varias veces durante sus 15 años en Altadena). Las frecuentes sequías en la cuenca de Los Ángeles resultan en grandes extensiones de vegetación reseca. Los infames vientos de Santa Ana, que soplan en la cuenca desde el este y el noreste, pueden provocar que los incendios se descontrolen rápidamente, como ocurrió con los incendios de Palisades y Eaton.

Los mapas de calidad del aire en tiempo real, como los del Distrito de Gestión de la Calidad del Aire de la Costa Sur (AQMD, por sus siglas en inglés) y la EPA de EE. UU., se basan en diversas fuentes para proporcionar datos durante todo el año. Los datos más detallados provienen de sofisticados instrumentos instalados por las propias agencias; el AQMD de la Costa Sur alberga 32 estaciones permanentes de monitoreo del aire en los condados de Los Ángeles, Orange, Riverside y San Bernardino.

Datos menos detallados, pero más generalizados, sobre material particulado provienen de redes de herramientas de medición de la calidad del aire disponibles comercialmente, como los monitores PurpleAir y los sensores Clarity, instalados por residentes u organizaciones comunitarias.

El Distrito de Gestión de la Calidad del Aire cuenta con instalaciones permanentes para monitorear la calidad del aire, pero tras los incendios forestales de Los Ángeles de enero de 2025, implementó iniciativas complementarias, recopilando datos de calidad del aire en tiempo real desde camionetas móviles de monitoreo. Crédito: South Coast AQMD.

“Resulta que las zonas donde se produjeron los incendios contaban con [una] red muy densa de estos sensores de bajo costo”, afirmó Scott Epstein, gerente de planificación y normativa del South Coast AQMD. “Al combinar esto con nuestra red regulatoria, obtuvimos una excelente cobertura de la contaminación por partículas finas”.

Esta densidad permitió a los investigadores observar las columnas de humo de los incendios forestales de Eaton y Palisades a medida que se dirigían hacia la costa.

Una estación del AQMD en Compton, a unos 37 kilómetros (23 millas) al sur del incendio de Eaton, mostró niveles muy elevados de metales tóxicos, como arsénico y plomo, entre el 7 y el 11 de enero, mientras la columna pasaba sobre la zona. Estos niveles se normalizaron en pocos días. Los instrumentos ASCENT en Pico Rivera, a unos 23 kilómetros (14 millas) al sur del incendio de Eaton, registraron un aumento de 110 veces en los niveles de plomo entre el 8 y el 11 de enero.

Estaciones permanentes de medición de la calidad del aire como estas ofrecen una fuente de información pública que residentes como Sinatra pueden consultar para decidir cuándo quedarse en casa o regresar a una zona quemada. Sin embargo, cuando estallaron los incendios de Palisades y Eaton, investigadores del AQMD y otras instituciones se propusieron complementar estos esfuerzos con un monitoreo más detallado.

Movilizándose rápidamente Melissa Bumstead (izquierda) y Jeni Knack se ofrecieron como voluntarias para recolectar muestras de aire y cenizas tras los incendios de Eaton y Palisades. Crédito: Shelly Magier.

En enero, investigadores de la Universidad de Harvard; la Universidad de California, Los Ángeles (UCLA); la Universidad de Texas en Austin; la Universidad del Sur de California (USC); y UC Davis lanzaron el Estudio de Exposición Humana y Salud a Largo Plazo de Los Angeles Fire, o LA Fire HEALTH.

Mientras muchos residentes de Los Ángeles, incluyendo a Sinatra, seguían bajo órdenes de evacuación, los investigadores de LA Fire HEALTH se dirigían a zonas de evacuación.

Uno de estos investigadores fue Nicholas Spada, un científico especializado en aerosoles que viajó a Los Ángeles desde UC Davis el 14 de enero para instalar cuatro impactadores en cascada en Santa Mónica (cerca del incendio de Palisades), Pasadena (cerca del incendio de Eaton), Hollywood y West Hills. Estos instrumentos, del tamaño de un maletín, actúan como máquinas clasificadoras de monedas, explicó Spada: toman una muestra de aire y clasifican las partículas en ocho categorías de tamaño diferentes, desde 10 micrómetros (aproximadamente 1/9 del grosor promedio de un cabello humano) hasta 90 nanómetros (aproximadamente 1/1000 del grosor de un cabello humano). Los instrumentos recogieron ocho muestras cada dos horas hasta el 10 de febrero.

El instrumento “capta los cambios en las columnas de humo a medida que el incendio progresa de activo a latente y luego a extinto para después seguircon los efectos de mitigación”.

Un impactador en cascada permite a los científicos “asociar los perfiles de tamaño de las partículas con el tiempo”, explicó Spada. El instrumento “capta los cambios en las columnas de humo a medida que el incendio progresa de activo a latente y luego a extinto para después seguircon los efectos de mitigación”.

Las mediciones mostraron que no solo había elementos tóxicos como el plomo y el arsénico presentes en el aire durante todo el período de muestreo, sino que también una alta proporción de su masa (alrededor del 25 %) se encontraba en forma de partículas ultrafinas (del orden de nanómetros). Estas partículas no son filtradas por las mascarillas N95 y pueden penetrar profundamente en el cuerpo al inhalarse, explicó Spada.

Un equipo de investigadores de la Universidad de Texas llegó en una camioneta que también funcionaba como laboratorio móvil el 2 de febrero. Para entonces, los incendios ya estaban extinguidos, pero ya habían comenzado las labores de remediación que causaban la acumulación de polvo. Descubrieron que la calidad del aire exterior en las semanas posteriores a los incendios había recuperado los niveles previos y se ajustaba a las directrices de la EPA. Las muestras de interiores, especialmente las de viviendas dentro de las zonas quemadas, mostraron niveles más altos de COVs en comparación con las muestras de exteriores.

Los vecinos tienden una mano

Los miembros de la comunidad se sumaron a los esfuerzos para monitorear la calidad del aire.

Los miembros de la comunidad del sur de California también se sumaron a los esfuerzos para monitorear la calidad del aire. Melissa Bumstead y Jeni Knack, codirectoras del Laboratorio de Campo de Padres Contra Santa Susana, trabajaron con investigadores para crear y distribuir folletos sobre las medidas adecuadas para el equipo de protección personal, así como un protocolo de auto muestreo para los residentes que desearan recolectar muestras de ceniza de sus propiedades.

Por aproximadamente dos veces a la semana, del 14 de enero al 19 de febrero, recolectaron muestras de aire y ceniza en Pasadena, Altadena, Santa Mónica, Topanga y Pacific Palisades, y luego las enviaron a laboratorios, incluido el de Spada, para su análisis. El arsénico en todas las muestras de ceniza y el plomo en aproximadamente un tercio de ellas superaron los niveles de detección regionales de la EPA. Spada señaló en sus comunicaciones a los residentes que estos niveles de detección se basan en lo que es seguro para la ingestión de un niño y son relativamente conservadores.

“Esto ayudará a las personas en la próxima iteración de incendios a saber qué hacer”, recordó Bumstead haberles dicho a los residentes en las zonas de muestreo.

Después de las cenizas Sinatra perdió su casa en Altadena en el incendio de Eaton de enero de 2025. Al regresar para excavar entre los escombros, recorrió chimenea tras chimenea sin ninguna casa. Crédito: Gale Sinatra

El próximo incendio, dijo Sinatra, es algo que la abruma mientras ella y sus vecinos consideran la posibilidad de reconstruir.

Cuando la lluvia finalmente llegó al sur de California el 26 de enero, ayudó a extinguir los incendios y a controlar el polvo acumulado durante las labores de remediación, reduciendo así el riesgo de inhalación de toxinas.

Aun así, esas toxinas también estaban presentes en el suelo y el agua. Cuando Sinatra y su esposo regresaron al lugar calcinado de su casa, tomaron todas las precauciones que habían escuchado en las noticias, la EPA, los líderes comunitarios y los vecinos: usaron respiradores, trajes de protección, gafas protectoras y dos pares de guantes cada uno para protegerse.

La preocupación por las posibles consecuencias a largo plazo del aire que ya habían respirado, así como del suelo bajo sus pies, persiste mientras esperan más datos.

“Todos creen que existe una probabilidad significativa de un incendio en el futuro”, dijo Sinatra. “Nos preguntamos si sería seguro vivir allí, considerando la calidad del suelo y del aire, y si volverá a ocurrir.”

—Emily Dieckman (@emfurd.bsky.social), Escritora Asociada.

This translation by Daniela Navarro-Pérez was made possible by a partnership with Planeteando and GeoLatinas. Esta traducción fue posible gracias a una asociación con Planeteando and GeoLatinas.

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

Deep learning’s (DL’s) promise and appeal is algorithmic amalgamation of all available data to achieve model generalization and prediction of complex systems. Thus, there is a need to design multivariate training and predictions tasks in order to identify all relevant connections between variables across different space and time scales.

Ouyang et al. [2025] propose a multi-task long-short-term memory (LSTM) neural network to predict time series of multiple hydrologic variables. In the application of the approach, by combining different variables in the prediction task and sharing information between them, improved physical consistency and accuracy is achieved. The authors demonstrate this in various prediction exercises of streamflow and evapotranspiration including conditions of data scarcity.

The study is a good example of how innovation within DL can realize the promise of generalizable hydrological models and predictions of complex systems in future. It also implicitly encourages hydrologists to expand their DL approaches for multi-tasking. After all, there is a plethora of data and computing resources available to achieve DL’s promise.

Citation: Ouyang, W., Gu, X., Ye, L., Liu, X., & Zhang, C. (2025). Exploring hydrological variable interconnections and enhancing predictions for data‐limited basins through multi‐task learning. Water Resources Research, 61, e2023WR036593. https://doi.org/10.1029/2023WR036593

—Stefan Kollet, Editor, Water Resources Research

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: AGU Advances

Rising carbon dioxide (CO2) levels are known to raise temperatures in Earth’s atmosphere. But slow feedback processes, including heat storage in the ocean and changes in the carbon cycle, mean that sometimes, such temperature changes don’t manifest right away; it can take decades, or even millennia, for Earth to reach equilibrium.

However, different climate models generate vastly different estimates of when such an equilibrium will be reached. One reason for these differences is the “pattern effect,” or the way uneven sea surface temperature changes can create distinct ocean warming patterns that affect atmospheric circulation and thus cloud cover, precipitation, and heat transfer. This complex interplay of factors can increase or decrease warming and shape the climate’s sensitivity to greenhouse gases.

One way to help predict what long-term warming patterns might look like is to turn to the past. Unearthing patterns in paleoclimate data, especially from times when Earth experienced a warmer climate, can provide insight into future warming patterns. Zhang et al. analyzed 10 million years of sea surface temperature records to determine the relative warming of different ocean regions under rising CO2 levels.

The study used the Western Pacific Warm Pool, the planet’s largest and warmest surface water body, as a reference point, comparing its sea surface temperature data with those of 17 other ocean sites to establish a global warming pattern.

The researchers then compared the warming shown in these paleoclimate data with the results of several models that simulate warming on the basis of an abrupt quadrupling of CO2 compared to preindustrial levels. They found the paleoclimate data and modeled results showed similar millennia-scale warming patterns, especially at higher latitudes. When both were compared to the past 160 years of sea surface temperature measurements, however, there were some differences in warming patterns. Modern warming is still in a transient state, influenced by ocean heat uptake, whereas the paleopattern represents the full equilibrium response.

It will take thousands of years to reach a new equilibrium, the researchers note. The study suggests that compared to the current transient warming, future warming patterns will be stronger at middle and high latitudes, including the North Pacific, North Atlantic, and Southern oceans. This high-latitude warming will likely be stronger than previous estimates suggested, and it is more pronounced in millennial-level than in century-level projections. (AGU Advances, https://doi.org/10.1029/2025AV001719, 2025)

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

Citation: Owen, R. (2025), Paleoclimate patterns offer hints about future warming, Eos, 106, https://doi.org/10.1029/2025EO250336. Published on 15 September 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.

Over the course of millennia, insects, spiders, and other arthropods in tropical forests have evolved in response to natural weather cycles like the El Niño–Southern Oscillation (ENSO).

With climate change, however, these global-scale phenomena are strengthening and becoming more frequent, and arthropods are unable to adapt. In a new study published in Nature, researchers found evidence that El Niño events influenced by global warming are chipping away at the diversity and functions of arthropods in tropical forests around the world.

To understand the effect of ENSO on arthropods, researchers led by University of Hong Kong entomologist Adam Sharp extracted data from studies conducted in tropical forests that have not been commercially altered by human activity, such as Barro Colorado Island in Panama, Mount Wilhelm in Papua New Guinea, and Kibale National Park in Uganda. These datasets included samples on arthropod diversity collected for 48 different species from 35 sites.

Using that information, the researchers created a model that allowed them to identify long-term trends in the diversity of different arthropod families through El Niño events from the 1990s until 2020.

They found a general decline among all the orders they analyzed, which included spiders, beetles, butterflies, cockroaches, termites, and other bugs. The only exception was Diptera, an insect order that includes flies and mosquitoes. Diptera was the only order whose species demonstrated increasing population trends during ENSO events.

Using this model, researchers were able to predict future declines as well as document current trends. They found that the most significant losses of biodiversity would most likely be among spiders, bugs, and butterflies.

The scientists also created a separate model to identify the effects of El Niño on the ecological services provided by arthropods, such as pollination, soil health, and pest control. To do so, they gathered data from studies that measured the amount of tree litter in tropical forests and the amount of damage to plant leaves caused by herbivore arthropods.

“In the models of leaf herbivory, we saw a big decline in the amount of leaves consumed by arthropods after around the year 2000. And this correlated strongly with what we predicted for the diversity of arthropods which would probably inflict that damage,” said Sharp. The model coincided with a decline in beetles in particular, he noted.

Mismatched Life Cycles

“Every time there’s a strong El Niño event, some of that biodiversity is chipped away and it doesn’t have time to recover before the next El Niño event.”

Sharp said that both models, although designed independently, support the same conclusion: “It looks as if every time there’s a strong El Niño event, some of that biodiversity is chipped away and it doesn’t have time to recover before the next El Niño event.”

Oliverio Delgado-Carrillo, an entomologist at the Universidad Nacional Autónoma de México who did not participate in the new study, said Sharp’s findings make sense in light of his own research, which focuses on a pollinator bee species associated with Mexican pumpkin flowers.

Delgado-Carrillo contributed to a paper published earlier this year in Global Change Biology that addressed the effects of climate change on the relationship between plants and pollinators.

Delgado-Carrillo and other researchers found that in general, flowers are beginning to bloom earlier, causing a mismatch between the life cycles of pollinators and their food supply. The pumpkin flowers studied by Delgado-Carrillo, for instance, bloomed before bees emerged from the soil, limiting the time available for pollination.

Sharp agreed with Delgado-Carrillo that more severe ENSO events will most likely cause more of these temporal mismatches between arthropods and plants.

Both researchers said the consequences of the decline in arthropod diversity are hard to predict but will likely be severe and far-reaching. In addition to effects on crops that rely on pollinators, for example, scientists point out that soil health would plummet without cockroaches processing leaf litter and other organic materials that provide nutrients to tropical soils.

In addition, Delgado-Carrillo expressed concern that without insects to control their populations, some opportunistic plants benefiting from climate change might outcompete less resilient species. “Herbivores are functioning as a kind of control mechanism for all those plants that could become dominant and interfere with these ecosystem processes,” he explained.

Filling the Data Gaps

Finally, Sharp and Delgado-Carrillo agreed that more research about ENSO and arthropods in tropical forests is needed. Sharp emphasized the knowledge gap surrounding tropical Africa and Southeast Asia in particular.

Yves Basset, an entomologist from the Smithsonian Tropical Research Institute in Panama, works on what’s most likely the only long-term continuous monitoring program of arthropods in tropical Latin America. His team’s work was one of the main sources of information for Sharp’s study, although he did not directly participate in the research himself.

For Basset, financing more projects like his in all tropical forests around the world is vital for understanding the effects of human-induced climate change on arthropods, especially for cyclic events like ENSO.

—Roberto González (@perrobertogg.bsky.social), Science Writer

Citation: González, R. (2025), El Niño may be driving insect decline in the tropics, Eos, 106, https://doi.org/10.1029/2025EO250339. Published on 15 September 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: Earth and Space Science

The surface of the Moon hides a complex and varied geology underneath. To unravel the Moon’s rich geological history, we rely on geophysical data acquired over decades of lunar missions. However, processing and interpretation of the remotely acquired data is not straightforward. Hence, new and sophisticated methods of processing and analyzing data are needed to extract the information necessary to detect and define lunar subsurface structures.

Ai et al. [2025] apply a new method combining an edge-detection algorithm, noise reduction techniques, and 3D inversion with high resolution gravity data from the Gravity Recovery and Interior Laboratory (GRAIL). The new approach allows them to sharply define the location and shape of a negative gravity anomaly beneath the Aristarchus Crater (the brightest feature on the Moon, located in Oceanus Procellarum, or “Ocean of Storms”). It confirms a complex geological setting involving crustal relief, fracturing caused by the impactor that formed the crater, dilation, and uplift of a volcanic unit. This study is important because it demonstrates a new method that will be useful to other researchers working on the Moon, and it advances our knowledge of lunar geology.  

Density contrast between subsurface masses in the subsurface of Aristarchus Crater. The distinction between negative anomaly (blue) and positive anomaly areas emerges very clearly, representing different geological processes.  The panels on the right indicate the performance of the models. Credit: Ai et al. [2025], Figure 21

Citation: Ai, H., Huang, Q., Ekinci, Y. L., Alvandi, A., & Narayan, S. (2025). Robust edge detection for structural mapping beneath the Aristarchus Plateau on the Moon using gravity data. Earth and Space Science, 12, e2025EA004379. https://doi.org/10.1029/2025EA004379

—Graziella Caprarelli, Editor-in-Chief, Earth and Space Science

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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 EPA proposed today that approximately 8,000 polluting facilities, including oil refineries, power plants, and steel mills, should no longer be required to report their greenhouse gas emissions.

Since 2010, the Greenhouse Gas Reporting Program has required that such facilities—spanning several dozen categories—report their emissions of greenhouse gases, such as carbon dioxide, to the government. The data is made public each October. According to the EPA’s own website, as it appeared today, the data can be used to “identify opportunities to cut pollution, minimize wasted energy, and save money,” as well as to “develop common-sense climate policies.”

 
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The EPA statement claimed that the reporting program “has no material impact on improving health and the environment.” EPA Administrator Lee Zeldin said in the statement that the program is “nothing more than bureaucratic red tape that does nothing to improve air quality.”

“Instead, it costs American businesses and manufacturing billions of dollars, driving up the cost of living, jeopardizing our nation’s prosperity and hurting American communities,” he said.

Environmental groups have pointed out that, without this data, regulations cannot be enacted to protect Americans from the harmful effects of greenhouse gas emissions and climate change.

“Some industries want to keep this secret so that the public can’t know who’s responsible and hold them to account,” David Doniger, a senior attorney at the Natural Resources Defense Council, told the Washington Post. “What the public doesn’t know, they can’t demand be regulated.”

The move is the latest of many moves by the Trump administration to reduce regulations surrounding greenhouse gas emissions and other environmental protections.

In June, for example, the EPA proposed repealing federal limits on power plant carbon emissions. In July, the agency proposed rescinding the 2009 Endangerment Finding, which found that greenhouse gas emissions threaten public health and welfare and has since underpinned the federal government’s efforts to mitigate climate change.

—Emily Gardner (@emfurd.bsky.social), Associate Editor

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Source: AGU Advances

Warm water flowing into fjords and beneath ice shelves will continue to be a prime cause of glacial melting as global temperatures rise. This melting will, in turn, contribute to sea level rise and increasing inundation of coastal areas.

As emission reductions fall short of international goals, scientists and some members of the public are discussing possibilities for using geoengineering to mitigate coastal flooding and other detrimental effects of climate warming. One proposal involves building barriers in the ocean to block warm water from reaching glaciers. For example, some scientists have proposed placing a floating steel curtain or an underwater rock wall around parts of the Greenland ice sheet to limit the influx of warm, ice-melting currents.

Such barriers would be difficult to construct, and it’s not clear how effective they would be, Hopwood et al. point out in a recent commentary focusing on the potential effects of this method on Greenland’s largest glacier, Sermeq Kujalleq.

What’s more, underwater walls are likely to come with substantial downsides for marine ecosystems. Modeling suggests that such barriers would interrupt a process by which glacial runoff pulls nutrient-rich water up from the deep ocean. This disruption, in turn, would reduce phytoplankton levels near the surface and the fish populations that depend on them—ultimately affecting the Greenlanders that rely on these fish for their livelihoods. Walls might also disrupt fish migration patterns, adding to the problem. The side effects of underwater walls are “unlikely to be socially acceptable,” the authors write. Walls built to protect Antarctic glaciers would have similar effects on local ecosystems, they suggest.

The researchers note that although glacier-guarding barriers are both hypothetical and unrealistic at this point, interest in geoengineering is likely to grow in the coming decades. Thus, it is important to keep the unintended consequences of such projects in mind.

Some researchers have suggested that geoengineering approaches should be tested so that policymakers can assess their costs and benefits on the basis of real-world data. But before they seriously consider these techniques, write Hopwood and colleagues, it’s crucial that scientists have conversations with local stakeholders to understand how the potential trade-offs could affect their lives and livelihoods. (AGU Advances, https://doi.org/10.1029/2025AV001732, 2025)

—Saima May Sidik (@saimamay.bsky.social), Science Writer

Citation: Sidik, S. M. (2025), Underwater glacier-guarding walls could have unintended consequences, Eos, 106, https://doi.org/10.1029/2025EO250334. Published on 12 September 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
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Source: Global Biogeochemical Cycles

For years, oceanographers have puzzled over why algorithms were detecting mysteriously high levels of particulate inorganic carbon (PIC) in satellite imagery of remote Antarctic waters. In other areas, high PIC is a sign of massive blooms of single-celled phytoplankton known as coccolithophores, whose shiny calcium carbonate shells reflect light back to satellites. However, these polar waters have long been thought to be too cold for coccolithophores to thrive in.

The mystery is now solved, thanks to new ship-based measurements from Balch et al. They discovered an abundance of a different type of phytoplankton known as diatoms, whose reflective silica shells, or frustules, can mimic the reflectivity of PIC when found at very high concentrations. This reflectivity can lead satellite algorithms to misclassify these far southern waters as high-PIC areas.

Earlier ship-based observations from the same research team had already confirmed that PIC from coccolithophores is responsible for the Great Calcite Belt—a massive, seasonal, reflective ring of water encircling Antarctica in warmer waters to the north. Farther south, however, unusually bright areas around the continent remained unexplained, with hypothesized causes including loose ice, bubbles, or reflective glacial “flour” (eroded rock particles) released into the ocean.

The researchers sailed south from Hawaii into the less explored waters—known for their icebergs and rough seas—aboard R/V Roger Revelle. They measured PIC and silica levels, determined photosynthesis rates, conducted optical measurements, and observed microbes under microscopes. Together the data revealed that the high reflectivity of these remote areas is primarily caused by diatom frustules.

However, the researchers were also surprised to detect some coccolithophores in the polar waters, suggesting these phytoplankton can survive in seas colder than previously thought.

The findings could have key implications for Earth’s carbon cycle, as both coccolithophores and diatoms play major roles in the fixation of oceanic carbon. This work could also inform improvement of satellite algorithms to better distinguish between PIC and diatom frustules, the researchers suggest. (Global Biogeochemical Cycles, https://doi.org/10.1029/2024GB008457, 2025)

—Sarah Stanley, Science Writer

Citation: Stanley, S. (2025), Mysteriously bright waters near Antarctica explained, Eos, 106, https://doi.org/10.1029/2025EO250337. Published on 12 September 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: AGU Advances

Quantifying the major elements of an earthquake energy budget is challenging. Seismologists can quantify the radiant energy that causes ground shaking, but they cannot quantify the other two major components: thermal dissipation and the energy that goes into creating new surface energy.

Since less than about 20% of an earthquake’s energy goes into radiation, approximately 80% of the budget is in question and represents a major unknown in earthquake physics. This is a significant limitation considering that the energy budget and the conversion of energy into various forms are one of the most powerful tools for describing natural phenomena in a robust and quantitative manner. The only way to resolve such lack of knowledge is by field-based and/or laboratory studies.

Using laboratory experiments, or “lab-quakes”, Ortega-Arroyo et al. [2025] quantify, for the first time, all three major components of the earthquake energy budget. Their findings open new opportunities for earthquake hazard assessment.

Citation: Ortega-Arroyo, D., O’Ghaffari, H., Peč, M., Gong, Z., Fu, R. R., Ohl, M., et al. (2025). “Lab-quakes”: Quantifying the complete energy budget of high-pressure laboratory failure. AGU Advances, 6, e2025AV001683. https://doi.org/10.1029/2025AV001683

—Alberto Montanari, Editor-in-Chief, AGU Advances

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

An analysis of 20 years of health data in eight Amazonian countries, published today in Communications Earth and Environment, shows that protecting Indigenous-managed forests may help reduce various kinds of disease, including fire-related respiratory diseases and illnesses spread by animals. 

The results are further evidence of the importance of ensuring Indigenous communities have land sovereignty and the tools to maintain healthy forests, the paper’s authors said. 

“Ensuring Indigenous communities have strong rights over their lands is the best way to keep forests and their health benefits intact.”

“Protecting more forest areas under Indigenous people’s management could significantly reduce atmospheric pollutants and improve human health outcomes,” the authors wrote. 

Deforestation in the Amazon often occurs via clear-cutting, a practice by which nearly all trees and vegetation in an area are cut down, left to dry, and burned. Smoke and especially tiny particulate matter (PM2.5) from these fires makes those living in the Amazon sick with respiratory and cardiovascular illnesses: In the Brazilian Amazon, for example, deforestation fires were responsible for 2,906 premature deaths each year, on average, between 2002 and 2011.

Zoonotic and vector-borne diseases, such as Chagas disease, malaria, hantavirus, rickettsia, and spotted fevers also affect the estimated 2.7 million Indigenous people living in the Amazon. 

According to the researchers’ analysis of disease incidence and landscape in 1,733 Amazonian municipalities, Indigenous-managed forests seem to mitigate each form of disease (fire-related, zoonotic, and vector-borne) in some cases, depending on the characteristics of the surrounding land.

The decades of data revealed that Indigenous territories were able to mitigate the impacts of PM2.5 on fire-related diseases when those territories were part of municipalities with high forest cover. Indigenous territories also decreased the risk of zoonotic and vector-borne diseases when those territories covered more than 40% of the municipality. 

The effects were more pronounced when Indigenous territories were legally protected. The results may be explained by the fact that Indigenous territories have previously been linked to decreased deforestation (and therefore fewer clear-cutting fires) as well as decreased biodiversity loss, which previous research suggests may reduce the transmission of pathogens.

 
Related

•  Deforestation Threatens Public Health. Securing Indigenous Land Rights Can Help, Researchers Find
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•  Read the Paper: Indigenous Territories Can Safeguard Human Health Depending on the Landscape Structure and Legal Status
 

In municipalities with fragmented forests or low forest cover, though, Indigenous territory was less effective in mitigating disease risk. 

“Indigenous forests in the Amazon bring health benefits to millions,” said Paula Prist, a biologist at the International Union for Conservation of Nature and Natural Resources and coauthor of the new study, in a statement. “Ensuring Indigenous communities have strong rights over their lands is the best way to keep forests and their health benefits intact.”

In Brazil, about a third of Indigenous territories lack a formal legal title even though Brazilian law requires the government to provide one, according to Inside Climate News. 

This year’s Conference of the Parties, or COP30, an annual UN climate change conference, will be held in the Amazon rainforest in Belem, Brazil. There, deforestation and ecological health are expected to be major topics of discussion. 

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

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

Ripples are bedforms on sandy sea beds in coastal regions that form and react to waves and currents. The sediment dynamics of these features are complex but important for understanding how coastal morphology can change at this scale.

DeVoe et al. [2025] investigate how sand and water behave inside and above these ripples. They use advanced computer models that combine fluid (using a Large Eddy Simulation) and sediment behavior (using a Discrete Particle Model) to find out how forces and shear stresses vary over and within a moving bed using a new mathematical method. The numerical method does not need assumptions of the near-bed boundary layer as required by other models and is an important new contribution toward understanding coastal sediment transport.

Diagram showing the numerical model domain, including the coordinate system and relevant dimensions. The mobile bed contains six sand ripples with wavelength (λr) and height (ηr), comprised of spherical sediment particles with diameter (dp). Flow over the bed oscillates in direction to simulate the influence of surface waves. Credit: DeVoe et al. [2025], Figure 1a

Citation: DeVoe, S. R., Wengrove, M. E., Foster, D. L., & Hagan, D. S. (2025). Characterization of the spatiotemporal distribution of shear stress and bedload flux within a mobile, rippled bed. Journal of Geophysical Research: Oceans, 130, e2025JC022369. https://doi.org/10.1029/2025JC022369

—Ryan P. Mulligan, Editor, JGR: Oceans

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Society experiences climate change most viscerally through high-impact events such as storms, floods, and droughts. The effects of these events felt by communities vary in their geography, timing, and severity and do not necessarily correspond to statistical descriptions of the extremity of hazards dominantly used by institutional scientists. For example, a landfalling category 3 hurricane may not be statistically rare for the United States—or, on the whole, “extreme”—but it can still upend lives and livelihoods where its impacts are felt most.

Opportunities exist to contextualize extremes with respect to time, place, and severity and to connect global change science with societal experiences.

The statistical significance of environmental hazards is often what is relayed through conventional metrics and risk communication. But if the metrics and communications don’t reflect or resonate with people’s lived experiences and interests, they’re less likely to be useful in helping inform and safeguard communities.

We propose that methods of analyzing, translating, and communicating Earth system science and the associated risks of high-impact events other than those conventionally applied in research can provide more relevant information to communities navigating climate-related environmental hazards.

Opportunities exist to contextualize extremes with respect to time, place, and severity and to connect global change science with societal experiences. Scientists who understand and take these opportunities are also more likely to make connections that translate data and raw science into locally tangible and actionable information.

Statistically Significant Versus High Impact

Scientists often use statistical tools, such as the t test, to assess whether changes in a variable or a set of conditions are statistically significant—for instance, in the attribution of a specific extreme to climate change. Although this approach works well for analyzing high-frequency data (daily mean temperature measurements, say), it is less applicable for characterizing rare events.

t tests assume normally distributed data and quantify what is rare or extreme in relation to that distribution. Yet climatic extremes themselves, by their nature, do not conform to normal distributions, and their statistical significance is not well represented when measured in this way. Indeed, changes in some extreme environmental hazards, such as in the frequency and intensity of tornadoes, are hard to model statistically. Although high-impact events that are rare historically may be happening more often, longer records than are typically available are necessary to demonstrate that changes in these events are truly statistically significant.

We recommend moving away from standard statistical practices for communicating about hazards.

We have often observed anecdotally that changes in quantities irrelevant to impact (e.g., a 1-millimeter increase in flood depth) are often found to be statistically significant, whereas changes in high-impact quantities (e.g., a small increase in hurricane wind speed that leads to dramatically different outcomes for residential properties) are deemed not statistically significant. This inconsistency is hardly surprising considering the paucity of extreme event records and may lead to miscommunication between those generating and those using information about the significance (statistical or not) of an extreme.

The question, then, is whether—and in which situations—it is useful or meaningful to discuss the statistical significance of changing extreme environmental hazards in risk communication. We find that “statistically significant” and “high impact” tend to be conflated and presented interchangeably in environmental hazard risk communication, even though they have different meanings and potentially very different repercussions for those facing the hazards. For instance, a statistically significant rise in local sea levels may only become high impact when it starts to interact with the built environment.

We, and other scientists, thus recommend moving away from standard statistical practices for communicating about hazards in favor of using probabilistic analyses founded on physical reasoning, which consider the likelihood (and likely consequences) of hazard occurrences [e.g., Shepherd, 2021].

Accounting for Lived Experiences

Reducing an event to whether it is statistically rare also removes considerations of human impacts and lived experiences and potentially keeps impactful (but not statistically significant) environmental hazards from being included in scientific analyses. Further, characterizing the significance of an event in isolation, apart from the interconnected ecosystem in which it occurs, can disconnect its measured significance from on-the-ground realities. Such realities can include intersecting and compounding impacts from the immediate effects of an event, as well as, for example, ongoing environmental injustices or legacies of extractive industrial activities. These impacts may inflict shocks and stresses on communities and ecosystems that are completely obscured by conventional scientific analyses.

Typically, scientifically determined indicators and metrics, such as those focused on projected averages, do not account for the variability and subtle, yet critical, site-specific nuances of local community contexts within which environmental hazards and climate effects occur. In many Indigenous communities, for example, locally informed and relevant metrics, such as the percentage of food sourced locally and the health and quality of the food for subsistence livelihoods and food sovereignty, are often based on multigenerational and Traditional Knowledges connected to and in relationship with place. Similarly, place-based climate impact data are often seen as more useful, relevant, and grounded in people’s lived experiences than climate data themselves.

Convergence and Cocreation

Here we provide examples of where community-focused metrics and risk communications can be valuable, highlighting convergence science and cocreated research on hazards and financial risk management.

Convergence science transcends disciplinary boundaries and weaves together knowledge systems, tools, and ways of thinking and understanding to tackle key societal and scientific challenges. It can be understood as “an expression of radically affirming the deep relationality of life of the planet, of Mother Earth, of the affirmation that we are all related” [Rising Voices, Changing Coasts Hub, 2024]. This collaborative framework, involving codesign and cocreation with community partners, enhances development of meaningful climate data and metrics [Lazrus et al., 2025]. It also looks beyond prevailing climate science metrics such as temperature to better understand how climate impacts are actually felt in place by different groups.

Shrimp nets, like the one seen here near Bayou Pointe Au Chien in June 2024, are a traditional means of harvesting seafood on the Louisiana coast. Credit: Julie Maldonado

For example, traditional harvesters on the working coast of Louisiana give attention to the health and quality of the seafood harvest and to what extent traditional diets and livelihoods can be sustained [Maldonado, 2019]. Measuring environmental impacts on this place-based community’s ability to maintain traditional livelihoods and lifeways [Barger et al., 2025; The Rising Voices Center for Indigenous and Earth Sciences, 2020] requires using definitions, metrics, and baselines defined by the community.

Another example comes from the Bering Sea–Bering Strait–Chukchi Sea region. In recent decades, dramatically and rapidly changing conditions of sea ice (location, extent, thickness, ice free days, seasonal shifts), ocean temperatures, permafrost thaw, and weather have profoundly affected communities in this part of the Arctic. Changes in sea ice have affected the safety of hunting practices, limited access to prey such as Pacific walrus, and threatened traditional methods of processing and storing harvested food in many communities that have relied for millennia on marine resources for food, culture, and community health and well-being [e.g., Apassingok et al., 2024]. Sea ice reductions have also increased communities’ vulnerability to the impacts of wind, waves, and coastal erosion [e.g., Overeem et al., 2011].

As in many low-lying communities on the Alaska coast, infrastructure and homes in Kotzebue, seen here, are growing more vulnerable with changing environmental conditions. Credit: iStock.com/ChrisBoswell

Major food shortages can result from compounding conditions that may not be extreme by themselves, such as the seasonal location of ever-shrinking sea ice and changing oceanic currents and temperatures, as well as issues of federal and state governance. Seasonal weather conditions and individual weather events—such as the October 2024 storm that caused severe flooding and damage to infrastructure in several coastal Alaskan towns—have also played roles in the extreme impacts experienced in the Bering-Chukchi region, even when these events themselves were not considered statistically extreme in isolation.

Conventional metrics and communications focused on statistically significant extremity can fail to capture how changing conditions are truly affecting the region’s peoples.

Whereas conventional metrics and communications focused on statistically significant extremity can fail to capture how changing conditions are truly affecting the region’s peoples, community-informed indicators focused more on food availability or traditional practices, for example, can be far more beneficial for guiding local decisionmaking.

A third example considers hazard metrics useful for financial risk management. Academic research into high-impact weather events in a changing climate typically compares hazard characteristics—of severe thunderstorms or tropical cyclones, say—between current and future climate periods and assesses the change in characteristics between the two periods. The timing of these future periods, however, can be somewhat arbitrary (e.g., at the end of this century).

Such assessments do not consider values or objectives of risk management, such as remaining financially solvent throughout the period leading up to the analyzed future period. They also provide information about conditions during only a narrow time window far in the future, whereas a financially destabilizing event that occurs sooner may render assessments of the more distant future obsolete.

A more usable metric would consider unacceptable risks to a given management objective, such as protecting lives or property, and calculate the time horizons at which these risks are likely to be crossed [Rye et al., 2021]. Such a metric would be cocreated by researchers and risk managers to link the changing character of hazards with management objectives. Framing climate change–induced risk in this way would allow it to be quantifiable and trackable by risk managers.

A similar approach has been proposed in engineering design, whereby the structural reliability of built infrastructure over a given service life (say, 100 years) is calculated from the maximum risk of a hazard occurring in each year to minimize associated failures [Rootzén and Katz, 2013].

An All-Hands-on-Deck Approach

The examples above by no means describe the full range of communities affected by environmental hazards, but they highlight the shared need for hazard information that is contextualized for time, place, and use.

Careful codesign of community-based metrics can enhance the relevance, uptake, and influence of geoscience information in societal decisionmaking.

Careful codesign of community-based metrics can enhance the relevance, uptake, and influence of geoscience information in societal decisionmaking [Jagannathan et al., 2021]. No single approach or framework for codesign exists. Rather, effective approaches are deeply specific to context and culture. They involve iterative processes of participatory, colearning knowledge exchange that require time and emotional labor—as well as effective mediation and shared learning strategies—to build and maintain relationships, mutual trust, and shared agreements [Jagannathan et al., 2021].

Such work should not be viewed apart from fundamental climate and global change science. On the contrary, it requires the weaving together of expertise and knowledge from many participants, including community members, practitioners, and institutional scientists. Through convergent and integrative approaches to environmental hazards research and risk communication, we can better understand—and communities can better respond to—changes in metrics that matter.

References

Apassingok, M., et al. (2024), How does the changing marine environment affect hunters’ access to Pacific walruses?, Arct. Antarct. Alpine Res., 56(1), 2367632, https://doi.org/10.1080/15230430.2024.2367632.

Barger, S., et al. (2025), Lessons from place: Indigenous-led rematriation for strengthening climate adaptation and resilience, J. Geogr., 124(3), 73–82, https://doi.org/10.1080/00221341.2025.2512244.

Jagannathan, K., A. D. Jones, and I. Ray (2021), The making of a metric: Co-producing decision-relevant climate science, Bull. Am. Meteorol. Soc., 102(8), E1579–E1590, https://doi.org/10.1175/BAMS-D-19-0296.1.

Lazrus, H., et al. (2025), Tapestries of knowledge: Using convergence science to weave Indigenous science and wisdom with other scientific approaches to climate challenges, Bull. Am. Meteorol. Soc., 106, E1558–E1565, https://doi.org/10.1175/BAMS-D-24-0215.1.

Maldonado, J. (2019), Seeking Justice in an Energy Sacrifice Zone: Standing on Vanishing Land in Coastal Louisiana, Routledge, London, www.routledge.com/Seeking-Justice-in-an-Energy-Sacrifice-Zone-Standing-on-Vanishing-Land-in-Coastal-Louisiana/Maldonado/p/book/9781629584010.

Overeem, I., et al. (2011), Sea ice loss enhances wave action at the Arctic coast, Geophys. Res. Lett., 38, L17503, https://doi.org/10.1029/2011GL048681.

Rising Voices, Changing Coasts Hub (2024), Co-created Knowledge and Actions: Moving from the Theory of Convergence Research to Practice, Working Group Session at 2024 National Tribal and Indigenous Climate Conference, Inst. for Tribal Environ. Prof., Anchorage, Alaska, 11 September, sites.google.com/view/nticc2024/home_1.

Rootzén, H., and R. W. Katz (2013), Design life level: Quantifying risk in a changing climate, Water Resour. Res., 49(9), 5,964–5,972, https://doi.org/10.1002/wrcr.20425.

Rye, C. J., J. A. Boyd, and A. Mitchell (2021), Normative approach to risk management for insurers, Nat. Clim. Change, 11(6), 460–463, https://doi.org/10.1038/s41558-021-01031-8.

Shepherd, T. G. (2021), Bringing physical reasoning into statistical practice in climate-change science, Clim. Change, 169(1–2), 2, https://doi.org/10.1007/s10584-021-03226-6.

The Rising Voices Center for Indigenous and Earth Sciences (2020), Rising Voices Workshop report on food systems, Rising Voices Workshop 2020, n2t.net/ark:/85065/d7s75mqf.

Author Information

Mari R. Tye (maritye@ucar.edu) and Laura Landrum, National Science Foundation National Center for Atmospheric Research, Boulder, Colo.; Julie Maldonado, Livelihoods Knowledge Exchange Network, Winchester, Ky.; and Diamond Tachera and James M. Done, National Science Foundation National Center for Atmospheric Research, Boulder, Colo.

Citation: Tye, M. R., L. Landrum, J. Maldonado, D. Tachera, and J. M. Done (2025), Environmental hazard impact metrics that matter, Eos, 106, https://doi.org/10.1029/2025EO250335. Published on 11 September 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.

Source: Community Science

When plastic waste enters waterways, it can endanger aquatic animals, damage habitats, and splinter into tiny pieces that may affect ecosystems for centuries to come.

One tool used to collect and study the trash found in bodies of water is the trash trap—an anchored floating device that funnels trash toward an enclosed collection area. Between 2021 and 2024, seven North Carolina Waterkeepers organizations installed 21 trash traps in streams around the state, periodically cleaning them out and collecting the contents. Lauer et al. analyzed the products of these cleanouts.

Staff and volunteers retrieved 150,750 pieces of litter from 368 cleanouts of the traps during the study period. They then organized the collected trash into different categories. Different organizations used different protocols, but the most common was developed by the Haw River Assembly (HRA) and the Duke University Environmental Law and Policy Clinic. The Duke/HRA protocol divided trash into six major groups (plastic film, hard plastic, foamed plastic, metal, glass, and “other”) and 33 subcategories, such as plastic bags, food wrappers, drink bottles, and polystyrene foam fragments (Styrofoam).

About 96% of trash categorized with the Duke/HRA protocol was plastic. Of this, 72.6%, or nearly 83,000 pieces, was Styrofoam fragments. This material was particularly tricky to catalog, the researchers noted, because it breaks down into tiny pieces that are difficult to retrieve.

More litter tended to accumulate in regions with higher populations and more development. Increased rainfall drove greater trash collection in about half the traps, because rain helps carry trash into rivers and streams. Similarly, traps located in areas with more impervious surfaces, such as streets and pavement, tended to accumulate more trash because these surfaces channel litter through storm drains and into nearby waterways.

The researchers note that trash traps do not collect all trash, and that cleanouts can be labor intensive, but they also highlight benefits of this type of data collection: It can help scientists understand local sources of litter, engage the public in community science, and provide a basis for targeted policies aimed at reducing plastic pollution. (Community Science, https://doi.org/10.1029/2024CSJ000122, 2025)

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

Citation: Owen, R. (2025), How North Carolina trash traps could help inform policy, Eos, 106, https://doi.org/10.1029/2025EO250283. Published on 11 September 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.