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

Most auroras appear in the “auroral oval” at high latitudes surrounding the magnetic poles. However, some can appear as a detached auroral arc from the auroral oval, at lower latitudes in mid-afternoon and connected to the oval only at a tip or two. Such a detached arc is believed to be linked to the “plasmaspheric plume,” the tongue-shaped extension of the plasmasphere during the recovery phase of a geomagnetic storm. (The plasmasphere is the torus-shaped region of cold, dense plasma above the low- and mid-latitude ionosphere.) The surface waves at the plume boundary cause it to ripple and modulate the various plasma waves in the plume.

Based on observations from multiple satellites and ground stations, Feng et al. [2026] find sawtooth-like undulations along the equatorward boundary of a detached auroral arc in the ultraviolet that was produced by energetic (>keV) electrons and accompanied by energetic (>10 keV) ions. The authors attribute the undulations to Electromagnetic Ion Cyclotron (EMIC) waves that are modulated by the surface waves and resonating with the energetic ions. The study unravels the fine-scale structures of detached auroral arcs and sheds important light on the dynamics underlying their formation.

Schematic illustration of the formation mechanism for the sawtooth-like undulations of a detached auroral arc. The surface waves modulate the Electromagnetic Ion Cyclotron (EMIC) waves in the plasmaspheric plume, causing the energetic ions to precipitate into the ionosphere and resulting in the formation of an afternoon detached auroral arc with sawtooth-like undulations. Credit: Feng et al. [2026], Figure 4

Citation: Feng, H., Wang, D., Hao, Y., Miyoshi, Y., Fu, H., Jun, C.-W., et al. (2026). First observation of sawtooth-like undulations in afternoon detached auroral arcs modulated by surface waves at the plasmaspheric plume boundary. AGU Advances, 7, e2025AV002234. https://doi.org/10.1029/2025AV002234

—Andrew Yau, Editor, AGU Advances

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Forecasts for the 2026 South Asia monsoon are for below average rainfall, but some of the most landslide prone areas of India may receive totals that are above average.

As usual, we are now starting to see the number of reported global fatal landslides increase as the northern hemisphere rainy season commences. In recent days, there have been fatal floods and landslides across several provinces of mainland China as well as landslides on the pilgrimage route to Kederath in northern India.

The global pattern is dominated by the South Asia (southwest / summer) monsoon, so it is interesting at this point to to consider the prospects for this year. The monsoon itself is expected to start in SW India next week, timing that is normal. It will then build over the following month or so.

The current forecast for the monsoon itself is that the total rainfall is likely to be below average. This is the WMO forecast:-

The WMO 2026 South Asia monsoon forecast from the WMO.

The map shows below average precipitation for much of South Asia. The IMD also forecasts below average rainfall.

Of course, in landslide terms we are interested mainly in SW India (Kerala), which has a below average forecast, and the mountainous areas of Pakistan, India, Nepal, Bhutan and Bangladesh. Much of this is also forecast to receive below average precipitation, but note the above average forecast for parts of northern India (Jammu and Kashmir, Himachal Pradesh) and NE India (Sikkim, Arunachal Pradesh). These are some of the most landslide-prone areas of India, suggesting that we may well see substantial landslide challenges in these areas.

The caveat of course is that monsoon-triggered landslides are sensitive to rainfall intensity as well as rainfall magnitude. A below average monsoon can bring intense rainfall events that trigged catastrophic landslides. Unfortunately, the forecasts cannot resolve this issue.

As an aside, the next few days in the European Alps will be interesting. We are about to see a few days of unusually high temperatures, which are likely to drive a wave of snowmelt and permafrost thawing. Given the time of year, this could well trigger extensive rockfall activity.

Unfortunately, by the time I get to Switzerland in nine days the weather is forecast to have reverted to cool drizzle!

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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.

Human-driven climate change is driving the rise of sea levels, worsening flood conditions and threatening coastal communities around the world. Not only is sea level rising, but it’s rising faster every year. Understanding the degree to which different processes contribute to sea level, known as the sea level budget, can help scientists better predict where and how quickly sea level will rise under potential climate futures.

 
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•  Read the paper: Improved closure of the global mean sea level budget from observational advances since 1960
•  The Global Impact of Losing U.S. Sea Level Science
 

But for several decades there has been a “budget gap” between measurements of sea level change and the total estimated contributions from glaciers, polar ice, land storage, and oceans expanding as they heat up (thermospheric expansion). Research published today in Science Advances has helped close that budget gap by incorporating more recent sea level observations, reconciling measurements taken by different instruments, and including recent community estimates of sea level rise and its components.

The new analysis breaks down the drivers of sea level rise from 1960 to 2023. The team found that the largest contributor is heat-driven expansion of seawater, responsible for 43% of sea level rise since 1960. Melting ice contributed the next largest amount of sea level rise: 27% came from mountain glaciers, while 15% came from the Greenland Ice Sheet and 12% from the Antarctic Ice Sheet. Lastly, sea level rose 3% as land reduced its capacity to store water.

Since 1960, 43% of global sea level rise can be attributed to thermal expansion of water, just 3% to a reduction in land water storage, and the remainder from melting ice and glaciers. Credit: Zheng et al., Science Advances (2026)

“For years, there has been a frustrating gap between how much the oceans were observed to be rising and how much we could explain from the individual causes,” John Abraham, an engineer at the University of St. Thomas in St Paul, Minn., and a coauthor on the new research, said in a press release. “This work shows that, with better instruments, processes, and smarter analysis, this knowledge gap can be closed. We can explain sea level rise with greater confidence.”

The researchers also calculated the rate at which sea level has risen since 1960 and how each component factored in. They found that the rate of sea level rise has recently doubled: It was 2 millimeters per year averaged over 1960­–2023 and 4 millimeters per year averaged over just 2005–2023. The strongest driver of that doubling is ocean warming, responsible for 41% of the accelerating rate of sea level rise, followed by reduced land water storage (21%).

In the past, glacial melt was the largest contributor to sea level rise before it was overtaken by thermospheric ocean expansion overtook (left). The rate of sea level rise has been speeding up since about 1980, also driven by thermospheric ocean expansion (right). Credit: Zheng et al., Science Advances (2026)

This research demonstrates the importance of maintaining detailed records of sea level rise, collecting new measurements, and not backing away from global change research. With better data on which processes contribute to sea level rise and its acceleration, policymakers and local communities can create informed mitigation strategies that account for future rise.

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

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Roughly the size of Texas, the Karoo Basin of central western South Africa is brutally dry, sparsely populated, and known in part for its potentially “massive” hydrocarbon deposits.

South Africa, which consumes more energy than any other country in sub-Saharan Africa, has shown a growing interest in commercial fracking for shale gas and oil across the Karoo hinterland, with the country moving in late 2025 to lift a 13-year ban on shale gas exploration in the area.

However, a recent study from the University of Cape Town, published in Seismological Research Letters, cautioned that the Karoo might not be as seismologically calm as it appears, meaning fracking efforts could have the potential to induce earthquakes in the region.

A Swarm of Earthquakes

The researchers observed 66 earthquakes in this cluster between 2007 and 2022, ranging from 0.7 to 4.8 in magnitude.

The researchers investigated what they call a sudden swarm of earthquakes that occurred in the Leeu Gamka cluster, a region of the Karoo that was previously considered seismically stable. They observed 66 earthquakes in this cluster between 2007 and 2022, ranging from 0.7 to 4.8 in magnitude.

“The individual earthquakes here are very small,” said Alastair Sloan, a tectonics and structural geologist at the University of Cape Town.

Using ambient noise tomography, previous geophysical surveys, and information about the locations of past earthquakes, the researchers identified a critically stressed fault underlying the region. The fault appears to extend for at least 30 kilometers roughly west-northwest to east-northeast.

Looking at South Africa more generally, there are other places where there have been “fairly large” earthquakes with a similar orientation, Sloan said. He cited a series of large earthquakes in the early 20th century in a place called Koffiefontein, north of the study area, and the disastrous 1969 Tulbagh earthquake, west of the team’s study area.

Both of those earthquakes occurred in regions that are geologically similar to the Karoo, though they’re outside of the area being considered for shale gas exploration, Sloan said.

Fracking Risks?

In other parts of the globe, such as Oklahoma in the United States, processes related to oil and gas extraction have led to “induced earthquakes.” Most of these earthquakes have been triggered by wastewater disposal associated with oil production, not by fracking directly.

Researchers are unsure if industrial fluid injection in the Karoo, as is applied in shale gas fracking processes, could trigger significant seismic action in the region’s existing faults.

“Some locations which undergo shale gas development don’t see very much seismicity, and there is a catalog of things which need to be present for [seismicity] to be something that you would particularly worry about,” Sloan said.

For instance, if faults are only within the crystalline basement and therefore separated from the sedimentary layers where the fracking occurs, then it’s not likely they’ll be reactivated, because there’s no way for the fracking fluid to get down to the fault zone itself. Another factor, Sloan added, is that for significant earthquakes to occur, large faults that are already critically stressed need to be present in the region undergoing fracking.

The new study showed that both of these conditions may be met in the Karoo: Microseismicity does extend to the depths at which the carbonaceous shale is present. And this microseismicity is occurring on a reasonably extensive structure with a similar orientation to larger earthquakes that have already occurred in the region.

However, Sloan stressed, this isn’t a cause for immediate panic.

“I don’t want to be too alarmist; the size of the structure revealed by the microseismicity is not huge, and so we do not have evidence to expect an earthquake much larger than the damaging historical earthquakes that we have already seen in the wider region,” he said. “Globally, large earthquakes triggered by fracking (rather than associated deep wastewater exposure) are very rare, but the study suggests the necessary preconditions are present. And so the possibility needs to be considered and monitored carefully.”

Not Unique

Raymond Durrheim, a geoscientist and the South African Research Chair in Exploration, Earthquake and Mining Seismology at the University of the Witwatersrand, and who also examined the Ph.D. thesis on which the new study is based, said no area is perfectly seismically quiet.

“We know the way seismicity works in this whole area of southern Africa is that swarms occur,” he said. “They’ll last for years or even decades, and then they’ll die away. This is not a unique occurrence.”

This study was “useful,” though, Durrheim added, especially with the possibility of shale gas development in the Karoo. “It’s very important that we understand this because we know that when you inject fluid under high pressure, there’s always a chance you could trigger an earthquake,” he said, noting examples of fluid injection triggering earthquakes in places such as Canada. “It’s always a risk.”

To mitigate risks, Sloan suggested it would be useful to have a much denser network of seismometers within this region of South Africa.

—Ray Mwareya (@RMwareya), Science Writer

Citation: Mwareya, R. (2026), A swarm of earthquakes in South Africa’s Karoo Basin poses questions for oil and gas development, Eos, 107, https://doi.org/10.1029/2026EO260159. Published on 20 May 2026. Text © 2026. 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: Water Resources Research

Evapotranspiration is a critical link between water, energy, and carbon. Scientists need to understand it well to accurately predict weather, droughts, streamflows, and even carbon emissions.

Eddy covariance towers, which measure changes in the atmosphere, are one of the primary ways that scientists measure evapotranspiration in an ecosystem. But these measurements often have a problem with energy imbalance, in which the measured fluxes of sensible heat and latent heat add up to less than they should. (Sensible heat refers to measurable temperature changes occurring via conduction or convection, whereas latent heat refers to water in the atmosphere changing phases.) There’s something missing—up to 30% of the system’s energy—in the math, and that can cause problems for later uses of the measurements, from forecasts to climate policies.

Scientists can adjust evapotranspiration measurements to try to correct for this problem, but a commonly used method to do so assumes that the Bowen ratio, or the ratio between sensible and latent heat, remains constant. However, this assumption may be flawed.

Raghav and Kumar present a new way of tackling this old problem without making assumptions about the Bowen ratio. It’s based on water use efficiency, which is how effectively plants use water to produce biomass.

The method first uses a suite of data from an eddy covariance tower to estimate evapotranspiration and energy balance through time. Then it derives the underlying water use efficiency potential while accounting for the influence of atmospheric dryness. In general, for a given vegetation type, this potential underlying efficiency is considered to be relatively stable over a growing season. The statistically smoothed potential underlying water use efficiencies is then compared to reference values derived during periods when the energy balance is well constrained. The ratio of the two is then used to correct evapotranspiration.

The new method is more consistent and more tied to the physics of plant physiology than current methods when results from each are compared, the authors found.

The new method is appropriate for use with any eddy covariance tower location or dataset because the authors used data from more than 250 towers around the world, in a range of ecosystem and climate types, to build their approach. However, they add, it may be less reliable in environments where evaporation dominates transpiration, such as wetlands. Nevertheless, the authors say, this work marks an important advance in measuring evapotranspiration, with broad implications for water management, agriculture, and adapting to climate extremes and drought. (Water Resources Research, https://doi.org/10.1029/2025WR042766, 2026)

—Rebecca Dzombak (@rdzombak.bsky.social), Science Writer

Citation: Dzombak, R. (2026), Improving eddy tower evapotranspiration estimates, Eos, 107, https://doi.org/10.1029/2026EO260163. Published on 20 May 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
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Tiny saltwater channels have a big influence on sea ice.

Sea ice typically includes pockets or channels of brine that allow salt water to flow vertically through the ice. When those channels align neatly, they need to make up only about 5% of the ice volume before the water can flow. But in more disordered, granular ice, salt water starts to flow only when the brine channels take up more space—roughly 10% of the ice volume, according to a new study published in Scientific Reports.

“If we’re trying to find predictive models about how these ice cores are responding under climate change, it’s going to be necessary to take into account these structural and microstructural conditions.”

This higher threshold could slow the drainage of surface melt ponds, as well as the transport of nutrients to microbial communities inside the ice.

“If we’re trying to find predictive models about how these ice cores are responding under climate change, it’s going to be necessary to take into account these structural and microstructural conditions,” said Stephen Ackley, a sea ice researcher at the University of Texas at San Antonio who was not involved in the study.

Disorderly Constructs

As seawater freezes, it forms a mixture of ice crystals and brine. In calm conditions, the ice slowly grows into long, parallel crystals separated by orderly brine channels. This columnar sea ice is common in the Arctic, and its properties have been widely used in sea ice models.

But in choppy waves or when the ice’s snow-covered surface floods and refreezes, new ice can’t grow into these ordered columns. Instead, it forms small, randomly oriented grains separated by more complex pores containing brine and gases. Called granular ice, this form is more common in Antarctica but is becoming increasingly prevalent in the Arctic as temperatures rise and ice cover thins.

“It’s the sequel we’ve been waiting decades for.”

In 1998, University of Utah mathematician Kenneth Golden established the first estimate of the point at which the brine channels are connected enough to allow water to flow in columnar ice, called the percolation threshold. The new work, also led by Golden, extends a similar analysis to granular sea ice.

“It’s the sequel we’ve been waiting decades for,” said Don Perovich, a sea ice researcher at Dartmouth who was not involved in the new work.

To quantify the percolation threshold for granular ice, Golden and his colleagues collected sea ice samples during two expeditions off the eastern coast of Antarctica in 2007 and 2012. They measured how quickly water moved through the brine channels in the ice. After the 2012 expedition, they also mapped the arrangement of ice crystals within the ice blocks to correlate those permeability measurements with the microscale structure of the ice.

Most climate models are based on the assumption that the microstructure of sea ice is organized into columns, like those in the image on the left. But new research shows that granular ice, as seen on the right, is growing more common in the Arctic, which could affect climate modeling. Credit: Golden et al., 2026, https://doi.org/10.1038/s41598-026-41706-w, CC BY-NC-ND 4.0

The finding that in granular ice, about twice as much of the ice volume needs to be brine for water to flow compared to columnar ice suggests that brine channels within granular ice are much less interconnected.

With the higher threshold, “you have to reassess all these models, anything that relies on fluid flow through sea ice,” if granular ice is present, said Golden. Granular ice will require warmer or saltier conditions to leave enough brine in the ice structure to meet the percolation threshold and allow water to flow vertically.

Researchers extracted blocks of ice in Antarctica with a chainsaw and poured dyed salt water on top. In this way, they observed how quickly the fluid descended through the ice. Credit: Kenneth Golden

For example, the new value could influence models of how meltwater ponds behave atop an underlying ice sheet. If meltwater ponds form above a base of granular sea ice, those ponds will require warmer temperatures before they start draining than melt ponds on columnar ice will.

If these melt ponds remain on the surface longer waiting for those warmer temperatures, they could lower the albedo, or reflectivity, of the ice sheet. That could cause the ice sheet to absorb more heat, leading to a feedback loop that could accelerate melting.

The higher percolation threshold could also affect algae that lives within the ice. Ice algae make up an important food source for krill and crustaceans, which in turn become food for fish, penguins, and whales. Algae rely on water flowing through the ice to deliver nutrients. Because granular ice requires warmer temperatures for that flow to start, it could affect the depth at which algae can live inside the ice, Golden said.

Percolation Consideration

Still, experts say more data are needed to establish percolation thresholds across both Arctic and Antarctic ice. The size of the grains in granular ice can vary substantially at different temperatures, under different formation conditions, and between the poles. Larger grains could lower the percolation threshold, allowing water to flow even when the ice contains much less than 10% brine by volume, said Sønke Maus, a scientist studying ice microstructure at the Norwegian University of Science and Technology who was not involved in the study.

“The data that we have at the moment for the granular sea ice is sparse,” Maus said. “You need a big campaign to collect such data.”

Golden said that in future work he also plans to develop models to compute the electromagnetic properties of both columnar and granular sea ice. Knowing these properties can help scientists determine the thickness and age of an ice sheet from satellite data.

—Skyler Ware (@skylerdware), Science Writer

Citation: Ware, S. (2026), Changes in sea ice microstructure could affect climate models, Eos, 107, https://doi.org/10.1029/2026EO260164. Published on 20 May 2026. Text © 2026. The authors. CC BY-NC-ND 3.0
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In British Columbia a CAN$115 million project is almost complete to mitigate the risk posed by debris flows to the town of Squamish.

Upstream of the town of Squamish in British Columbia, Canada, an extraordinary project is underway to mitigate the risk of debris flows. Known as the Cheekeye Debris Barrier Project, the scheme involves the construction of a concrete barrier that is 24 metres high across the Cheekeye Fan, designed to catch debris flows with a volume up to 2.4 million cubic metres of debris.

The project is almost complete, with hand-over expected in the summer of this year. There is an excellent article about the project on The Tyee website, which includes some very interesting images of the structure. The estimated cost of the project is around CAN$115 million. The location of the Cheekeye Debris Barrier Project is [49.79417, 1123.10878]. This is a render of the final form of the barrier (but take a look at the images of the almost completed structure too):

A render of the completed Cheekeye Debris Barrier. Image via the District of Squamish.

This is a fascinating project that makes a great case study for teaching, not least because both the detailed design considerations and the regulatory process for approving the programme are available in detail.

In terms of the detailed design considerations, there is an excellent open access paper in the Canadian Geotechnical Journal (Lesueur et al. 2025) that provides a very comprehensive analysis of the estimation of the potential volume and mobility of the debris flows on the Cheekeye Fan, and of the considerations that went into the final deisign of the structure.

In terms of the approval process, the District of Squamish has an online archive of documents and Council minutes that extends back to 2003.

I would highlight the challenges around determining the optimal size of a barrier of this type. The team has been balancing risk against cost, following the principle as outlined in Lesueur et al. (2025):-

“The local government specifies that tolerable debris-flow risks be reduced “as low as reasonably practicable” (ALARP), defined in this project as the point where the cost of additional mitigation measures is grossly disproportionate to the benefits gained.”

Thus, the barrier is not designed to stop the maximum credible debris flow, which is 5.5 million cubic metres (more than double the design event). This is pragmatic engineering at its best, and the Cheekeye Debris Barrier Project provides the level of detail that allows the decision-making process to be fully understood.

Reference

LeSueur, P. et al. 2026. Risk-informed design of debris-flow mitigation at Cheekeye Fan. Canadian Geotechnical Journal. 62: 1-16. https://doi.org/10.1139/cgj-2023-0008

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The Intergovernmental Panel on Climate Change (IPCC), the United Nations body whose mission is to “provide governments at all levels with scientific information that they can use to develop climate policies” will likely update the emissions and land use scenarios used in the models it considers in its bellwether assessment reports.

The IPCC has used these scenarios, known as Shared Socioeconomic Pathways (SSPs) or Representative Concentration Pathways (RCPs), in its two most recent assessment reports (AR), AR5 released in 2014 and AR6 released in 2023. The upcoming AR7 will be informed by a new set of scenarios, as described in a paper published last month in Geoscientific Model Development.

The paper is drawing widespread attention—both within the scientific community and in wider discourse—for its statement regarding one current scenario that has become familiar to anyone following climate science and policy. The scientists said the emissions levels associated with the most extreme, worst-case scenario, SSP5-8.5 (and its predecessor, RCP8.5), “have become implausible.”

 
Related

•  On the death of RCP8.5, from The Climate Brink
•  Read the study: The Scenario Model Intercomparison Project for CMIP7
•  Scientists now say this worst-case climate scenario is ‘implausible.’ Here’s what it means.
 

Even President Donald Trump weighed in with a post on Truth Social on 17 May, where he wrote “GOOD RIDDANCE,” and “the United Nations TOP Climate Committee just admitted that its own projections (RCP8.5) were WRONG! WRONG! WRONG!”

But as scientists have pointed out for years, RCP8.5 was never meant to represent a likely emissions scenario or a forecast of humanity’s future. Some scientists questioned whether it’s even possible for RCP8.5 to play out in real life. 

RCP8.5 is one of four hypothetical emissions scenarios developed in 2011 for climate modeling experiments. When RCP8.5 was created, it was meant to represent a “very high baseline emission scenario” that would warm the world nearly 5°C (9°F) compared with preindustrial temperatures by 2100. Parallel scenarios (SSPs) were presented in 2017. SSP5-8.5 is the worst-case scenario in that framework, representing a world in which fossil fuels are widely exploited and more of the world adopts energy-intensive lifestyles alongside the warming projected by RCP8.5. 

“The scenarios we create today are different than the scenarios we created 15 years ago, because the world is different today than 15 years ago.”

The authors of the new paper wrote that “trends in the costs of renewables, the emergence of climate policy and recent emissions trends” justify the implausibility of the highest-emissions scenarios such as RCP8.5 and SSP5-8.5. 

For scientists, the idea of dropping these scenarios is neither new nor controversial. As three climate scientists (Zeke Hausfather of Berkeley Earth, Glen Peters of the CICERO Center for International Climate Research, and Piers Forster at the University of Leeds) wrote in a blog post: “[RCP8.5] was never a likely outcome even in a world that did not address climate change; rather it was always intended to represent a worst case scenario that pushed fossil fuel expansion to the max.”

The new scenarios presented in Geoscientific Model Development include a high-emissions scenario in which clean energy policy is rolled back, and the world warms about 3.5°C (6.3°F) by 2100—still a level at which humanity can expect very severe impacts, from worsening weather extremes to rapidly rising sea levels.

The IPCC’s likely elimination of RCP8.5, even if it was never a plausible scenario, is a small sign of improvement in global climate change mitigation efforts, Hausfather, Peters, and Forster wrote: “Rapid declines in clean energy costs have bent the curve of future emissions downward, with new scenarios designed to reflect current policies notably lower than most baseline scenarios in the literature.”

“Of course, we still have a long way to go to get emissions down to (net) zero and stabilize global temperatures,” they noted.

The new paper captures the difficult road ahead for climate action: The new scenarios are based on a reduced projection for the increase in emissions, not for the overall amount of emissions—those are still increasing. Unlike before, none of the new emissions scenarios keep the world below 1.5°C (2.7°F) of warming, the limit originally set by the Paris Agreement in 2016. That’s no surprise to scientists, who suggest Earth is already in the 20-year period in which warming will formally surpass this benchmark. 

“The scenarios we create today are different than the scenarios we created 15 years ago, because the world is different today than 15 years ago,” Hausfather told the Washington Post.

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

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Months after wildfires eliminate vegetation that holds hillside sediment together, debris flows—destructive landslides that carry bulky material down once-stable slopes—can devastate infrastructure, taking out roads and buildings in their wake.

Though the U.S. Geological Survey (USGS) creates hazard predictions used to warn communities of the risk of these postfire debris flows, those predictions haven’t fully considered how recovering vegetation reduces risk over time—until now.

A new study published in Geosphere presents a new way to calculate postfire debris flow risk that takes vegetation recovery into account. The USGS will begin using the new method this wildfire season to create more accurate maps of debris flow hazard in the years after a fire.

“I’m so appreciative that the focus on how the debris flow hazard changes over time after fire is being addressed,” said Nancy Calhoun, a geologist and postwildfire debris flow program manager at the Washington Geological Survey who was not involved in the new study. Calhoun said she relies on the USGS hazard assessments for virtually everything her job requires.

“We’re glad to have a way that we can help our partners moderate those situations where the hazard has decreased,” said Andrew Graber, a geologist at the USGS Landslide Hazards Program and lead author of the new study.

Assessing Hazard, Again

After a wildfire, the USGS creates hazard maps that incorporate information about soil type, steepness, and burn severity (how much vegetation has been lost) to show where the risk of a debris flow may be elevated.

Then, the agency distributes this guidance to the National Weather Service, which uses it to set rainfall thresholds: levels of rainfall at which a debris flow becomes likely. State, county, and city agencies use those rainfall thresholds to issue warnings or take action when rainfall is imminent, for example, by closing highways or triggering evacuations.

“That left us with some uncertainty when we started to get further away in time from the fire.”

The methods used to create the USGS maps, however, historically relied on a snapshot of the burned area taken just after the fire, and the maps weren’t updated to reflect conditions as vegetation grew back and began holding soil in place again.

That led to situations where public safety decisions were made on the basis of outdated maps and rainfall thresholds. For example, concern over debris flows after the 2020 Grizzly Creek Fire in Colorado led to several closures of Interstate 70 in 2022, but the debris flows never happened.

“What [the original assessments] didn’t capture is how the vegetation came back,” Graber said. “That left us with some uncertainty when we started to get further away in time from the fire.”

Intense rainfall in July 2025 triggered a debris flow near Dayton, Wyo., in the 2024 Elk Fire burn area. Credit: USGS, Public Domain

To test an improved method for these hazard assessments, Graber and the research team incorporated satellite imagery of 12 burned areas that showed the degree of vegetation recovery right after the fire, 1 year after the fire, and 2 years after the fire. Then, they tested their new method by comparing its predictions to rainfall and debris flow data from the 12 burned areas.

The updated method better reflected what had actually happened after the fires, reducing the number of unnecessary warnings without missing real-world debris flows.

Risk Recalibration

The USGS plans to begin using their new workflow to create hazard maps for some higher-profile fires during the coming wildfire season.

“It’s a really important question: Are we still worried about this burn scar?”

That’s exciting for Calhoun. As part of her job, she’s in constant contact with emergency managers who periodically ask how worried they should be about debris flows in areas that burned years ago. “It’s a really important question: Are we still worried about this burn scar?” she said.

Right now, Calhoun has no data to point to in the years after a fire to give an updated answer to that question. Using the new method from Graber and the research team, she will.

“Because they’re using satellite [imagery] and repeatable quantitative methods to look at these burn scars over time, we’ll actually be able to say something useful and informed about vegetation recovery,” she said.

Having a deeper understanding of how debris flow risk evolves over time is especially important because debris flows themselves are becoming a greater risk to the public as a result of increasingly intense wildfires and rainstorms. In addition, more accurate assessments can reduce warning fatigue, which occurs when too many false alarms lead to people ignoring or opting out of alerts.

Graber hopes he and the USGS will continue to improve their methods for assessing debris flow hazards by collecting more debris flow data across the country and improving the underlying equation for hazard assessments so that it better reflects the unique conditions of different ecosystems in the United States. USGS researchers also published a new study in March presenting a method to generate maps of where debris flows might travel if they do occur.

“It’s a big year for USGS’s useful postfire products,” Calhoun said.

—Grace van Deelen (@gvd.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: van Deelen, G. (2026), A new approach can better predict debris flow hazards years after fires, Eos, 107, https://doi.org/10.1029/2026EO260160. Published on 19 May 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
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Source: Geophysical Research Letters  

Real-time hydrologic forecasting predicts river level and flooding inundation by combining continuously updated rainfall measurements, river gauge readings, and weather forecasts. Most of these flood forecasting systems depend on human interpretation and adjustments, or a “forecasters-in-the-loop” approach, which pairs computer models with a human expert on flood dynamics and local conditions. In contrast, in a “forecasters-over-the-loop” system, humans supervise automated forecasts and intervene only if necessary.

Recently, artificial intelligence (AI) and machine learning (ML) have become more integrated into flood prediction, and many of these systems are faster at processing large datasets and learning complex patterns from historical records than traditional models alone. But these new technologies also come with limitations—AI and ML require extensive data and may struggle to capture extreme, rare events.

Even though ML and AI are often touted as the future of flood forecasting, most studies have tested this technology against models that provide historical simulations, not the real-time operational systems that would be used during a flood. These simplified models may lack local details or are tested at daily rather than hourly resolution. Their effectiveness may be overestimated. 

Tran et al. produced the first study comparing the performance of ML models to an actual flood forecasting system used at the California Nevada River Forecast Center (CNRFC) that uses professional forecasters and traditional hydrologic models. The study suggests that a forecasters-in-the-loop approach outperforms the ML models in several key ways, including streamflow predictions and flood event detection, because forecasters can recognize model errors and account for poor input data—actions models cannot take on their own.

The researchers used data gathered from CNRFC river stage forecasts across 50 California and Nevada locations between 2012 and 2022 and river condition lead times from 1 to 96 hours. Compared to the ML models, the Community Hydrologic Prediction System used at CNRFC generally performed better at predicting stream flow and flood peaks, especially with longer lead times. Though the ML models could perform better at very short lead times, their accuracy declined quickly. Though automated forecasting options may seem promising, they are not yet a suitable replacement for human expertise when it comes to protecting lives and livelihoods from damaging floods, the researchers say. (Geophysical Research Letters, https://doi.org/10.1029/2025GL118317, 2026)

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

Citation: Owen. R. (2026), Keeping humans in the loop improves flood forecasting, Eos, 107, https://doi.org/10.1029/2026EO260161. Published on 19 May 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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

Sediment transport shapes the Earth surface in different ways, by forming desert dunes and by sculpting the topography of rivers, but the physics of sediment transport initiation is still incompletely understood. For decades, models have generally assumed two basic entrainment mechanisms: a grain resting on the sediment bed is either lifted directly by fluid forces, or it is emitted from the soil indirectly, as product of a granular splash caused by the heavy impact of another grain.

However, recent breakthroughs in grain-based simulations and high-speed visualization have been offering a much clearer look at the processes that trigger grain motion. Insights from these recent advances have revealed a rather broad spectrum of indirect particle-particle and particle-fluid interactions driving entrainment, including the rearrangement of surface grains after splash and changes in near‐bed flow structure due to moving grains. These interactions exert non-local influences on transport thresholds, giving rise to a dynamic process known as collective particle entrainment—a mechanism that remains poorly understood at a fundamental level.

In a new study, Chartrand [2026] shows that collective particle entrainment is size-dependent: large grains interact primarily with their peers, while smaller grains are mobilized by both large and similar-sized particles. This distinction leads to divergent transport signatures, with a new stochastic model predicting temporally correlated motion for small grains and uncorrelated, white-noise entrainment statistics for larger particles.

Although theoretical modeling will be required to shed further light on the physics of collective entrainment, the author’s study is a step toward a quantitative model of sediment transport from a probabilistic perspective. Looking ahead, Chartrand’s ideas could now be extended to other environments, potentially transforming our understanding of entrainment in other contexts such as wind-blown transport and extraterrestrial atmospheric processes.

Citation: Chartrand, S. M. (2026). Collective particle entrainment explored with experimental data and coupled transfer functions. Journal of Geophysical Research: Earth Surface, 131, e2025JF008657. https://doi.org/10.1029/2025JF008657

—Eric Parteli, Associate Editor, JGR: Earth Surface

Text © 2026. The authors. CC BY-NC-ND 3.0
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Central Mongolia’s Hangay Mountains have long posed a conundrum. Rising 4 kilometers above sea level, the dome-shaped range plays a key role in shaping the region’s climate. But it couldn’t have formed in the same way as most equally tall mountain ranges.

“These mountains in central Mongolia are very far from any plate boundary, about 5,000 kilometers away from the Pacific margin,” said Pengfei Li, a geologist at the Chinese Academy of Sciences’ Guangzhou Institute of Geochemistry. “It’s very hard to understand why we have such a mountain range so far from the plate boundary.”

Li recently led research finding that geochemical evidence supports a compelling explanation of how these oddball mountains formed. The researchers proposed that at the site of the future mountains, a U-shaped bend in a tectonic plate led to an extra-thick lithosphere. A chunk of that heavy lithosphere eventually broke off and sunk into the mantle. Free of the extra weight, the crust then rebounded upward as the Hangay Mountains.

Bend and Snap

“It’s the first discovery of volcanism for this period.”

Tectonic plates are far from rigid. As they move above, below, and against each other, sections of the plates far from the boundary can develop curves and folds like a scrunched up tablecloth. Curved sections, called oroclines, are common around the world. At about 6,000 kilometers long, the Mongolian orocline is one of the longest, and the Hangay Mountains sit right at the curviest part of the orocline’s U shape.

Li and his colleagues suspected that the Hangays’ location along the orocline is no coincidence. During multiple field expeditions from 2018 through 2026, the researchers collected rock samples from several sites in the Hangay Mountains that showed signs of ancient volcanic activity. Uranium-lead dating of zircons within those samples showed that the area experienced volcanic activity in the early Cretaceous period 124–114 million years ago.

“When I saw the age, I was surprised,” Li said. “120 million years—no one had ever reported volcanoes [in Mongolia] during this period.…It’s the first discovery of volcanism for this period.”

The team also analyzed the samples for major and trace elements to determine the depth at which the rocks formed. Their geochemical analysis revealed that the rocks formed in the lithosphere 80 kilometers below the surface. They published these results in Geology in April.

It’s pretty odd that the rocks originated so deep, Li said, because the modern-day lithosphere is only 70 kilometers thick.

The team proposed that when the continental plate folded and created the Mongolian orocline 200 million years ago, the lithosphere bunched up and became thicker in the curve of the U shape. That thicker section of lithosphere, a root at least 80 kilometers thick, would have been unstable in the long term, Li explained.

The lithospheric root would have been too heavy to remain attached to the crust above for long, and a chunk of it would have eventually snapped off. When it sunk, or foundered, into the deep mantle, it would have melted and generated the volcanic activity recorded in the rocks the team studied. Free from the weight of that lithospheric root, the crust above would have rebounded into the dome-shaped mountain range visible today.

Complicated Yet Compelling

“Their story, though complicated, makes a great deal of sense and in a way provides affirmation of a prediction made some time ago regarding oroclines.”

“The story that [the researchers] have put together to explain the massive Hangay topographic ‘dome’ of central west Mongolia is a compelling one that spans more than the past 200 million years of Earth history,” said Stephen Johnston, a tectonics researcher at the University of Alberta in Canada who was not involved with this research. Past research into the Iberian orocline suggested that oroclines might lead to lithospheric thickening, and this explanation of the Hangay Mountains fits that narrative.

“Their story, though complicated, makes a great deal of sense and in a way provides affirmation of a prediction made some time ago regarding oroclines,” Johnston added.

Johnston said that the new explanation of how the Hangay Mountains formed makes him wonder why it took so long—80 million years—between when the orocline formed and when the lithospheric root sank.

“This seems a long time for a gravitationally unstable mantle root to have remained attached to the overlying crust,” he said. He hopes that future work can help determine whether this process has taken place at other oroclines around the world and has simply been overlooked or whether there is something special about the Mongolian orocline.

Li and his team have turned their attention to how the formation of the Hangay Mountains shaped the region’s ancient climate. Today, the towering mountain range prevents moist air from northern Mongolia from reaching the parched Gobi Desert in the south. They hope to connect how a process deep underground, like lithospheric foundering, affected the paleoclimate and, consequently, the region’s habitability.

“It’s very new to try to understand the Earth’s habitability from a deeper sense,” Li said.

—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. (2026), Mongolian mountains rose when the crust bounced back, Eos, 107, https://doi.org/10.1029/2026EO260153. Published on 15 May 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
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Since the beginning of the 20th century, global sea level has risen by about 20 centimeters (roughly 8 inches) [Fox-Kemper et al., 2021]. As a result, coastal and island communities around the world are experiencing more frequent high-tide flooding, worsening storm surges, and increasing damage to homes and infrastructure. In the United States, for example, human-caused sea level rise alone increased damages from 2012’s Hurricane Sandy by about $8 billion [Strauss et al., 2021].

The United States has long been a key member of the global climate research community. However, that role is now threatened.

Scientific understanding of the magnitudes and rates of sea level rise, of how they vary around the planet, and of why the ocean is rising is based on a body of rigorous research that, for decades, has tracked past and present sea levels and projected future rise.

The United States has long been a key member of the global climate research community, including in producing the wealth of sea level research that has informed countries, states, and communities of what lies ahead for their shorelines. However, that role is now threatened by the Trump administration’s attacks on the country’s scientific research enterprise broadly and on climate research especially.

Analysis of the evolution of sea level rise projection science [Garner et al., 2018] underscores both the country’s prominent past role in the field and how the ongoing attacks may undermine progress in our understanding of sea level change. It also points to the urgency of acting across multiple fronts to preserve scientific knowledge and prevent further harm to the capacity to measure and project how much and how fast rising seas will affect global coastlines.

Four Decades of Advancing Sea Level Science

By the late 1970s, scientists around the world had begun to recognize the growing threat that climate change posed to the Greenland and Antarctic ice sheets and the danger their melting presented to coastal regions [Mercer, 1978]. The first global mean sea level (GMSL) projections were published in 1982 [Gornitz et al., 1982], and the first planning-oriented sea level scenarios were published just a few years later [e.g., National Research Council, 1987].

Since 1982, 103 studies have produced GMSL projections [Garner et al., 2018]. About one third of the studies (33 in total), including the first five, were published by teams led by scientists at U.S. institutions (Figure 1). Thirty-three studies (some, but not all, of which were also led by U.S.-based scientists) have also benefited from U.S. federal funding, sometimes from multiple agencies (Figure 2), including the National Science Foundation (NSF; 16 studies), NASA (10 studies), NOAA (8 studies), the U.S. Department of Energy (DOE; 6 studies), the U.S. Department of Defense (3 studies), the U.S. Geological Survey (2 studies), and the EPA (2 studies).

Fig. 1. This time series shows the total number of sea level rise projection studies published each year from 1982 to 2025 (gray bars) and the number of studies each year that were led by scientists based at U.S. institutions (purple bars). The text at top left tabulates the total number of studies led by authors in each country or region listed. Fig. 2. The total number of sea level rise projection studies published each year from 1982 to 2025 is shown again here (gray bars), this time beside the number of studies each year that were supported by funding from various U.S. federal science agencies (stacked colored bars). Note that some studies were supported by more than one U.S. federal agency.

U.S. scientists have further played critical roles in developing GMSL projections for Intergovernmental Panel on Climate Change (IPCC) assessments. For example, chapters producing sea level projections for the IPCC Fifth Assessment Report [Church et al., 2013], the IPCC Special Report on the Ocean and Cryosphere in a Changing Climate [Oppenheimer et al., 2019], and the IPCC Sixth Assessment Report (AR6) [Fox-Kemper et al., 2021] were all coled by U.S.-based scientists.

Meanwhile, U.S. funding has been essential to the IPCC, constituting more than 25% of the nearly $207 million invested globally in the organization from 1989 to 2024 [IPCC, 2025]. NASA also played a key role in making IPCC AR6 sea level projections more accessible and usable through the NASA/IPCC Sea Level Projection Tool [Kopp et al., 2023; Fox-Kemper et al., 2021; Garner et al., 2021], which supports local assessments of sea level change around the world and has about 400,000 users annually.

U.S. institutions have been vital in developing, hosting, and maintaining critical sea level datasets.

Beyond direct contributions of U.S. scientists and federal funding to the global scientific community’s sea level projection research, U.S. institutions have been vital in developing, hosting, and maintaining critical sea level datasets. For example, the University of Hawai‘i Sea Level Center is a crucial part of the Global Sea Level Observing System, operating a network of more than 90 tide gauge stations and supporting global real-time oceanographic operations and long-term climate studies. NASA satellite missions, including TOPEX/Poseidon and the Gravity Recovery and Climate Experiment (GRACE and GRACE-FO), have been instrumental in helping to measure changes in GMSL and ice sheets, providing new ways to assess the accuracy of global sea level projections [Törnqvist et al., 2025]. And the Sea Level Research Group at the University of Colorado has consistently processed such datasets, providing critical data access for the broader research community.

Pushed to a Precipice

Since January 2025, climate and sea level science in the United States has come under an unprecedented attack. Scientists have seen congressionally approved research funding revoked or frozen. Agencies like NASA, NOAA, and NSF have been stripped of physical resources, talented scientific experts, and independent advisory and governing boards. The Trump administration, in its fiscal year (FY) 2026 budget, sought debilitating funding cuts for federal scientific agencies, including proposed budget reductions of 24% for NASA, 27% for NOAA, 57% for NSF, and 55% for EPA. Although the scale of these cuts was reduced in the enacted FY2026 budget, the administration is pushing for similarly steep cuts in its FY2027 budget request.

In May 2025, NASA’s Goddard Institute for Space Studies, which produced the first global sea level projections [Gornitz et al., 1982], was evicted from its 49-year home, and efforts to undermine the institute have continued into 2026. Since December, the administration has advanced plans to dismantle the National Center for Atmospheric Research, which developed and maintains a host of climate datasets and resources, including the Community Earth System Model that is widely used to help generate GMSL projections. And in January 2026, the government announced it would withdraw from more than 60 international bodies, including the IPCC, as part of a broader move to pull back from international scientific cooperation.

Efforts to apply climate science in U.S. policy have been hindered not only by political polarization and proposed funding cuts but also by deliberate suppression of data and research.

Efforts to apply climate science in U.S. policy have been hindered not only by political polarization and proposed funding cuts but also by deliberate suppression of data and research. Broadly, the current U.S. administration has removed more than 2,000 datasets from federal platforms, and more specifically, it has systematically scrubbed climate-related content from agency websites. Such erasures disrupt public access to critical information and undermine scientific transparency.

Furthermore, the DOE published a report that without conducting any statistical analysis, denied the scientific evidence for sea level acceleration. It similarly claimed, without any analysis of the numerous sea level projection studies documented here, that sea level is “rising at a lower rate than predicted.” The EPA went further, falsely claiming that “aggregate sea level rise has been minimal.” In fact, the most recent IPCC sea level projections are in good agreement with observations [Törnqvist et al., 2025; Dessler and Kopp, 2025].

The U.S. scientific community now stands at a precipice. Efforts to dismantle federal scientific agencies and diminish research are eroding the United States’ foundational contributions to our knowledge of global change and sea level rise.

The Path to Preserving Critical Science

As we plummet toward a loss of data, expertise, and innovation, we face a future that would not only further damage the United States’ reputation for scientific excellence and transparency but also cripple the global sea level research community at a time when the risks from sea level rise are rapidly increasing [Fox-Kemper et al., 2021].

While some U.S.-based sea level scientists could move to countries more committed to climate science, there are not enough positions in the world nor enough mobility for the vast majority to relocate. Grassroots archiving efforts have helped preserve some critical datasets, but this is a temporary and often insufficient stopgap. An urgent need remains for resilient and transparent scientific infrastructure, so that U.S. taxpayer–funded research findings and datasets are, and remain, publicly accessible.

Historically, federally funded scientific initiatives have enjoyed strong support across the political spectrum in the United States.

Historically, federally funded scientific initiatives have enjoyed strong support across the political spectrum in the United States. However, the unprecedented hostility facing science in the country today has revealed that new institutional safeguards and legal protections to prevent political interference are critically needed.

Expanding collaborations between U.S. universities and private foundations and donors provides one potential route to providing some protection and improving long-term stability for sea level science data and initiatives. Climate Central’s Surging Seas project offers one model to emulate. However, philanthropic efforts are far from sufficient to preserve the U.S. scientific enterprise.

Another avenue to protect federally funded science from political pressure is through bipartisan legislation. Bills such as the Scientific Integrity Act (which aims to ensure that scientific findings are not influenced or altered by political pressure) and the Protect America’s Workforce Act (which aims to restore collective bargaining rights for unionized federal employees) represent such opportunities.

Yet the effectiveness of such legislative efforts hinges on the critical caveat that the people holding authority in government recognize and abide by enacted legislation. Under an executive who does not abide by the rule of law, such legislative efforts, even if they are passed successfully, will offer little actual protection. The path to preserving U.S. climate and sea level science, therefore, cannot be separated from the path to restoring the rule of law within the U.S. government.

Progressing on this front requires the scientific community to advocate for its priorities more vocally and to build coalitions that include both academics and the stakeholders who benefit from scientific climate projections. It also requires making use of tools and levers that many scientists are unaccustomed to, such as the court system. AGU and other institutions have modeled this approach over the past year, joining legal efforts to protect federal workers, for example, and speaking up against the dismantling of valued science agencies.

Restoring the rule of law also requires electoral organizing to reestablish Congress as an independent and coequal branch of government that wields, rather than abdicates, lawful oversight of administration officials and federal agencies.

Scientific understanding of sea level processes and projections of future changes inform local, national, and international decisionmaking and provide a pathway to resilience against the risks of rising coastal waters. Safeguarding the long-standing leadership, integrity, and continuity of U.S. climate and sea level science is both a national and global imperative—one that many scientists are already stepping up to support. Now we need the rest of the scientific community—and its allies in academia, philanthropy, industry, and the public—to join in.

Acknowledgments

The authors thank Amy Appollina and Jessica Slotter for their assistance in curating a database of global sea level rise projections.

References

Church, J. A., et al. (2013), Sea level change, in Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, edited by T. F. Stocker et al., pp. 1,137–1,216, Cambridge Univ. Press, Cambridge, U.K., https://doi.org/10.1017/CBO9781107415324.026.

Dessler, A., and R. E. Kopp (2025), Climate experts’ review of the DOE Climate Working Group Report, ESS Open Archive, https://doi.org/10.22541/ESSOAR.175745244.41950365/V2.

Fox-Kemper, B., et al. (2021), Ocean, cryosphere and sea level change, in Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change, edited by V. Masson-Delmotte et al., pp. 1,211–1,362, Cambridge Univ. Press, Cambridge, U.K., https://doi.org/10.1017/9781009157896.011.

Garner, A. J., et al. (2018), Evolution of 21st century sea level rise projections, Earth’s Future, 6, 1,603–1,615, https://doi.org/10.1029/2018EF000991.

Garner, G. G., et al. (2021), IPCC AR6 Sea Level Projection Tool, NASA Sea Level Change Portal, sealevel.nasa.gov/data_tools/17.

Gornitz, V., S. Lebedeff, and J. Hansen (1982), Global sea level trend in the past century, Science, 215(4540), 1,611–1,614, https://doi.org/10.1126/science.215.4540.1611.

Intergovernmental Panel on Climate Change (IPCC) (2025), IPCC Trust Fund Programme and Budget, IPCC-LXII/Doc. 2, rev. 1, IPCC Secr., Geneva, Switzerland, apps.ipcc.ch/eventmanager/documents/88/180220250655-Doc.%202,%20Rev.1%20-%20IPCC%20Programme%20and%20Budget.pdf.

Kopp, R. E., et al. (2023), The Framework for Assessing Changes To Sea-level (FACTS) v1.0: A platform for characterizing parametric and structural uncertainty in future global, relative, and extreme sea-level change, Geosci. Model Dev., 16, 7,461–7,489, https://doi.org/10.5194/gmd-16-7461-2023.

Mercer, J. (1978), West Antarctic ice sheet and CO2 greenhouse effect: A threat of disaster, Nature, 271, 321–325, https://doi.org/10.1038/271321a0.

National Research Council (1987), Responding to Changes in Sea Level: Engineering Implications, Natl. Acad. Press, Washington, D.C.

Oppenheimer, M., et al. (2019), Sea level rise and implications for low-lying islands, coasts and communities, in IPCC Special Report on the Ocean and Cryosphere in a Changing Climate, edited by H.-O. Pörtner et al., pp. 321–445, Cambridge Univ. Press, Cambridge, U.K., https://doi.org/10.1017/9781009157964.006.

Strauss, B. H., et al. (2021), Economic damages from Hurricane Sandy attributable to sea level rise caused by anthropogenic climate change, Nat. Commun., 12, 2720, https://doi.org/10.1038/s41467-021-22838-1.

Törnqvist, T. E., et al. (2025), Evaluating IPCC projections of global sea-level change from the pre-satellite era, Earth’s Future, 13, e2025EF006533, https://doi.org/10.1029/2025EF006533.

Author Information

Andra J. Garner (garnera@rowan.edu), Department of Environmental Science, Rowan University, Glassboro, N.J.; Robert E. Kopp, Department of Earth and Planetary Sciences and Rutgers Climate and Energy Institute, Rutgers University, New Brunswick, N.J.; Gregory G. Garner, Glassboro, N.J.; Aimée B. A. Slangen, Department of Estuarine and Delta Systems, Royal Netherlands Institute for Sea Research, Yerseke; and Benjamin P. Horton, School of Energy and Environment, City University of Hong Kong

Citation: Garner, A. J., R. E. Kopp, G. G. Garner, A. B. A. Slangen, and B. P. Horton (2026), The global impact of losing U.S. sea level science, Eos, 107, https://doi.org/10.1029/2026EO260156. Published on 15 May 2026. 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 © 2026. 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

Across the western United States, wildfires are increasing in size and intensity. As the climate continues to warm, more extreme wildfires will reshape landscapes and pose a growing risk to human health and natural ecosystems throughout the West.

Climate models, used to predict other effects of climate change, are unable to directly simulate wildfires. Instead, researchers link previously burned areas to climate variables such as temperature, precipitation, drought, and evaporation, then apply those relationships to future climate projections.

Many recent studies have connected higher vapor pressure deficit (VPD)—a measure of atmospheric dryness—to more area burned in previous fires. VPD increases as the temperature rises, so models that rely on it generally predict an increase in wildfire activity as the climate warms.

Cheng et al. raise questions about the role VPD plays in modeling wildfire, suggesting that VPD is a poor measure of fuel dryness at larger scales and overestimates potential burned areas under significant warming conditions. Instead, researchers suggest soil moisture could be a more reliable indicator of fuel dryness and lead to more moderate projections of wildfire increases.

The researchers looked at five forested ecoregions in the western states. Using the Western US MTBS-Interagency wildfire dataset from 1984 to 2020 combined with climate data (temperature, VPD, and soil moisture), the researchers analyzed drivers of the area burned from May through October. They connected this information with output from climate models to look at future burn potential.

VPD-based wildfire predictions increase sharply under warming conditions. These predictions showed that under 3°C of average global warming, 16 times as much land would burn by the end of the century, compared to historical levels. Under 4°C of warming, up to 66 times more land would burn by the end of the century. This “truly massive” increase, the authors say, would mean fires consuming vegetation almost as soon as it regrows.

Soil moisture, on the other hand, provides a more moderate, though still concerning, picture. Under the same warming scenarios, soil moisture changes would lead to an increase in burned area of only 2–3 times that of the historical period. The researchers argue that projections relying on VPD severely exaggerate wildfire risk. (AGU Advances, https://doi.org/10.1029/2026AV002350, 2026)

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

Citation: Owen, R. (2026), How much will western wildfires worsen under warming?, Eos, 107, https://doi.org/10.1029/2026EO260147. Published on 15 May 2026. Text © 2026. 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.

On 19 July 2025, intense, long duration rainfall triggered over 550 landslides in Sancheong, South Korea, killing at least 10 people.

On 19 July 2025, extremely heavy rainfall triggered multiple landslides in Sancheong, South Korea. This event has been described by a new paper (Nguyen et al. 2026) just published in the journal Landslides. The paper is behind a paywall, but this link should give you access at the time of writing.

The core of the affected area is at [35.4333, 127.9111] (as usual, Landslides provides the location in degrees minutes and seconds when digital degrees is so much more useful – a pet frustration of mine!). This is a Planet Labs image of a part of the area, captured before the event. The marker is at the coordinate noted above:-

Planet Labs image of a part of the area affected by landslides during heavy rainfall in Sancheong County, South Korea on 19 July 2025. Image copyright Planet Labs, used with permission. Image dated 10 July 2025.

And this is the same area after 19 July 2025:-

Planet Labs image of a part of the area affected by landslides during heavy rainfall in Sancheong County, South Korea on 19 July 2025. Image copyright Planet Labs, used with permission. Image dated 23 July 2025.

And here is a slider to allow a comparison:-

Images by Planet Labs.

Nguyen et al. (2026) have mapped 568 individual landslides triggered by this rainfall event, triggered by rainfall in the range of 498 – 619 mm over a c. 55 hour period. These landslides killed at least 10 people and caused damage to homes and infrastructure. It is estimated that the restoration costs are in the order of US$800 million.

In common with many other events of this type, the landslides are mainly shallow, translational failures in soil or regolith on steeper slopes. As I have frequently noted, such terrain is very susceptible to unusually intense rainfall events, which often trigger a cluster of landslides in close proximity. These often merge to form channelised debris flows. Nguyen et al. (2026) note however that their modelling indicates that it was a combination of the intensity of the rainfall and its duration that led to these failures.

As rainfall intensities increase due to climate change, we are seeing increasing numbers of these landslide clusters. I greatly welcome studies such as Nguyen et al. (2026) , which allow us to build understanding in each case.

Reference and acknowledgement

Nguyen, H.H.D., Song, C.H. & Kim, Y.T. 2026. Physically based data-driven analysis for large-scale investigation of the July 2025 rainfall-induced landslide in Sancheong, South Korea. Landslides. https://doi.org/10.1007/s10346-026-02778-x

Planet Team 20246. Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/

Return to The Landslide Blog homepage Text © 2026. The authors. CC BY-NC-ND 3.0
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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 National Science Foundation (NSF) has eliminated its postdoctoral fellowship funding for Earth scientists.

On the NSF website, the opportunity is listed as “archived.” This first came to the attention of Eos this week, although a Redditor had posted about the opportunity being archived as far back as March.

 Related

•  Earth Sciences Postdoctoral Fellowships (Archived)
•  NSF announces organizational realignment
•  Get Involved: AGU Science Policy Action Center
 

“What do you do when the most powerful people in the country just decide that your field shouldn’t exist anymore?” asked one Earth scientist on Bluesky.

“So, what are we doing now that we’re just not going to have new grants in GEO?” asked another.

According to the last program solicitation, posted in October 2024, the program generally awarded about $2.78 million each year, funding 8 to 10 postdoctoral fellowships. Proposals could be related to any of the disciplines within the scope of NSF’s Division of Earth Sciences (EAR), part of the NSF Directorate for Geosciences (NSF GEO).

The NSF announced an “organizational realignment” in December 2025. As part of the agencywide reorganization, GEO gained new leadership in February 2026. Joydip Kundu, the new NSF GEO Directorate Head, first joined NSF GEO in July 2025 as the agency’s deputy assistance director, coming from the NSF Directorate for Computer and Information Science and Engineering. He previously worked for the White House Office of Management and Budget (under President Obama) and the University of Maryland. Like Kundu, NSF’s new deputy directorate heads also came from within the agency.

When contacted about the archived opportunity, an NSF spokesperson confirmed to Eos that “The EAR postdoc fellowship solicitation has been archived and will not have a competition this fall. NSF regularly evaluates its portfolio of funding opportunities and will continue to explore funding opportunities for early career geoscientists.”

NSF continues to offer fellowship opportunities to postdoctoral researchers in the fields of engineering, entrepreneurial research, mathematics and physical sciences. Fellowships to postdocs in biology are available only if they involve the use of artificial intelligence.

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

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 © 2026. AGU. CC BY-NC-ND 3.0
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The retreat of glaciers and ice sheets is expected to have widespread impacts on communities around the world because of its effect on sea levels. Already, the global average sea level is more than 10 centimeters higher than it was just 3 decades ago; and the rate of rise is increasing, contributing to increased storm surges and flooding, lost infrastructure and community lands, and more.

Recent reports on the instability of Antarctica’s Thwaites Glacier, for example, have focused attention on how accelerating ice flow can lead to ice sheet collapse and rising sea levels.

Recent reports on the instability of Antarctica’s Thwaites Glacier, for example, have focused attention on how accelerating ice flow can lead to ice sheet collapse and rising sea levels. Yet there is still substantial uncertainty about how quickly Thwaites and other glaciers will lose ice, in part because we don’t fully understand the myriad processes that contribute to their mass balance.

Earth’s ice sheets accumulate ice through snowfall and lose mass through a mix of surface ablation, iceberg calving, and melting at their interface with the ocean. Glacial ice flows under its own weight, and the rate at which it flows to coastal areas is a primary control on ice sheet mass loss.

Flow rates depend on how much resistance an ice sheet encounters at its interface with the ground (e.g., whether it is frozen to its substrate) and on its effective viscosity, a measure of how strongly it resists deformation. The viscosity of ice, in turn, varies based on properties including temperature, crystal size and orientation, and impurity content.

Some properties within and beneath ice sheets that affect how they flow are anisotropic, meaning they vary by direction. For example, roughness in some directions at the ice bed can facilitate ice sliding more effectively than roughness in other directions, similar to the way a properly oriented corrugated metal roof allows snow to slide off. Several forms of anisotropy within ice also affect how ice flows from land to ocean (Figure 1).

Fig. 1. Anisotropy in glaciers and ice sheets has various sources, including from ice fabric and other properties within the ice (englacial) or at the ice-bed interface. Many forms of anisotropy in glacial ice can be measured with radar. Credit: Adapted from Hills et al., 2025, https://doi.org/10.1029/2024RG000842, CC BY 4.0

Measuring anisotropic properties is key to better understanding how quickly changes at the edges of the Greenland and Antarctic ice sheets will lead to sea level rise. Recent advances in ice-penetrating radar technology and in processing radar data are revolutionizing how we observe directionally varying ice sheet properties, paving the way for projections of mass changes that account for previously neglected processes.

Crystal Fabric: Memory and Modulator of Ice Flow

Fabric, the orientation of crystals composing ice, is the best studied and arguably most important of anisotropic ice sheet properties. As ice deforms, for example, by stretching horizontally as it flows toward the coast, its millimeter-scale crystals are reoriented (Figure 1).

Fabric thus contains a memory of past flow. Simultaneously, fabric influences flow because ice crystals are about 3 orders of magnitude easier to shear in some directions than others—similar to how stacked playing cards slide easily against each other when held along their edges but resist motion when pinched top to bottom.

Over the past 20 years, radar polarimetry has matured into a quicker and easier alternative means for inferring fabric.

The potential importance of fabric on large-scale ice flow has long been recognized, but a shortage of observations has made it difficult to quantify and validate its effect in ice sheet models. Until recently, fabric could be measured only directly in ice cores or inferred through seismic soundings. These methods provide highly detailed information about how fabric develops but are expensive, logistically taxing, and provide information only about sparse point locations.

Over the past 20 years, though, radar polarimetry has matured into a quicker and easier alternative means for inferring fabric, enabling observations at the scale of entire glaciers and providing new constraints on how fabric influences ice sheet flow.

How Radar Reveals Fabric

Ice-penetrating radar instruments emit electromagnetic energy as radio frequency waves. These waves reflect off interfaces within and beneath glacial ice, including transitions in ice chemistry and the contact surface between the ice sheet and the ground or water below. The properties of the reflected waves are then measured when they return to the radar. Just as fabric leads to anisotropic ice deformation, it also introduces directional dependence in the measured electrical properties.

The speed of a radar wave through an ice crystal is approximately 1% faster if the wave is polarized across the crystal’s principal (c) axis rather than aligned with it. Though small, this difference can compound enough that it causes measurable changes in returned radar signals.

In a typical radar survey over anisotropic ice, waves with different polarizations travel at slightly different speeds (Figure 2). The times that return signals arrive back at the receiver thus vary directionally, a difference that can be identified using polarimetric radars that transmit and receive radio waves at multiple orientations.

Fig. 2. Propagation of polarized radio waves through anisotropic ice reveals structural variations with depth because waves aligned across the prevailing ice fabric (represented by the ball, in which darker shading indicates a greater concentration of c axes) travel faster than waves aligned with the fabric. The phase delay increases as the effect of the anisotropy accumulates with depth. Credit: Adapted from Hills et al., 2025, https://doi.org/10.1029/2024RG000842, CC BY 4.0

Fabric’s effect on radar signal travel times accumulates through an ice column, so it is more prominent in thicker ice with stronger horizontal fabric (i.e., the ice crystals are more consistently aligned). In such cases, differences in travel times between polarizations can be measured even by standard radars.

When fabric is weaker or ice is thinner, the offset is smaller and detectable only by systems that can identify the phases of radar returns—that is, the exact positions of the returned waves in their oscillation cycle. Even small wave speed differences from weak fabrics accumulate into measurable phase shifts between polarizations, which can be used to determine the consistency of crystal alignment and the predominant crystal orientation.

Small differences in fabric through an ice column can also change the strength, or amplitude, of returned signals. This amplitude difference offers an independent way to identify fabric orientation and its depth variation.

Polarimetric radar has been widely applied in cryospheric science in recent years largely due to the advent of low-cost systems that can measure signal phases. For example, the popular Autonomous phase-sensitive Radio Echo Sounder (ApRES) is a lightweight, ground-based system that can be used to infer ice fabric at single points down to 2 kilometers deep. In the past decade, polarimetric ApRES systems have revealed ice flow histories, including changes in flow directions, of key glaciers over the past few millennia. These measurements offer windows into how ice sheets responded to previous climate variations.

A mobile, quad-polarimetric radar is dragged by snowmobile over the surface of Müller Ice Cap on Axel Heiberg Island in Nunavut, Canada, in May 2023. Credit: David Lilien

The next generation of polarimetric radars go beyond one-point-at-a-time stationary soundings, offering full polarimetry capabilities on moving platforms. These systems may soon allow scientists to map directional ice properties at the scale of entire ice sheets.

Insights into Fast-Flowing Ice Fabric

The growing number of radar studies conducted near sites where ice cores have been collected, which allow fabric to be investigated up close, has provided validation and bolstered confidence that fabric can be inferred accurately from its effects on radar. Researchers now infer fabric from radar in more dynamic areas, such as Thwaites Glacier, Whillans Ice Stream, and the Northeast Greenland Ice Stream (NEGIS), where ice fabrics change over short spatial scales and where drilling ice cores is logistically difficult. Airborne radar surveys are particularly effective in these settings because they can efficiently map fabric variations across large, fast-moving areas.

Observations of strong fabrics in fast-flowing regions suggest that fabric is an important control on ice viscosity, although its implications for ice flow are just beginning to be explored. For example, at Rutford Ice Stream in Antarctica, ApRES data indicate that fabric causes sharp changes in viscosity in different directions with depth, a complexity not captured by current ice flow models.

A combination of airborne and ground-based radar shows that the fabric of the NEGIS varies substantially across the ice stream, which facilitates horizontal shear that allows faster and more cohesive flow in the middle of the ice stream while simultaneously stiffening this ice against along-flow stretching. These viscosity variations may alter how quickly coastal changes, such as increased melt due to climate warming, influence inland ice flow.

Scientists have studied ice sheet mass balance at glacier-mounted stations along the renowned “K-transect” near Kangerlussuaq in southwestern Greenland since the early 1990s. This image shows a view up the transect in April 2025. Polarimetric radar offers another tool with which to study ice flow here and at other locations on the ice sheets. Credit: Tamara Gerber

The emerging consensus from radar observations and recent progress in fabric modeling is that ice fabric can soften ice stream shear margins by a factor of 10. In other words, the fabric tends to develop in a way that greatly reduces the ice’s effective viscosity at lateral boundaries between fast-flowing and slower-flowing ice, which enables the ice to deform more easily at the margins. The agreement between observations and process-scale modeling highlights fabric as a major, but largely ignored, control on ice flow that may affect estimates of how ice dynamics will contribute to future sea level rise.

Beyond Fabric

Most polarimetric radar studies so far have focused on fabric, but other ice characteristics can cause directional effects too. For instance, bubbles trapped in ice have dramatically different properties than ice itself. Ice deformation can bring bubbles into alignment, such that they affect radar waves differently in different directions.

Likewise, ice at its melting point can contain liquid water along boundaries between crystals, and if those pockets of water are aligned in one direction, they can also affect radar returns. Each of these properties has important influences on ice flow, but their implications are yet to be explored.

Another source of anisotropy is the bottom boundary of the ice sheet. This interface can be rougher in some directions than others, though the roughness is typically aligned with the prevailing ice flow direction or the direction of meltwater trapped within the ice.

Polarimetric radar can measure directionally dependent properties of ice sheet bases at a finer scale than radar profiling can. Such work is leading to new insights into glacier geomorphology, interactions of ice shelf bottoms with the underlying ocean, and how ice slides over substrate surfaces. Rates and extents of sub-ice-shelf melt and basal sliding are widely recognized as key controls on the future of the ice sheets.

Expanding Horizons: Large-Scale and Planetary Applications

Radar polarimetry has already transformed our understanding of ice fabric, revealing much about how crystal alignment modulates the flow of Earth’s ice sheets and filling critical gaps between the handful of direct measurements from ice cores. As polarimetric techniques mature, their applications are expanding.

Researchers are moving from studying isolated profiles of ice fabric to mapping it across whole basins, a key shift for validating bespoke models of fabric and its effects on flow. These models are also rapidly developing to include additional physical processes (e.g., migration recrystallization) and key simplifications (e.g., reducing directionally varying viscosity to a single number) that allow them to interface more easily with—and be incorporated into—large-scale models used for projecting sea level rise.

Techniques pioneered for measuring ice on Earth may also prove useful elsewhere in the solar system.

Techniques pioneered for measuring ice on Earth may also prove useful elsewhere in the solar system. Orbital radar sounders have already probed Mars’s ice masses, and the icy shell of Jupiter’s moon Europa will soon be surveyed by single-polarization radars aboard NASA’s Europa Clipper and the European Space Agency’s Jupiter Icy Moons Explorer (JUICE). These radars might be useful for polarimetry at some locations on Europa, which could reveal past and present motion of ice features and answer fundamental questions about the moon. Whether Europa’s shell flows, for example, may be key to whether its subsurface ocean can harbor life.

As polarimetric radar systems become routine tools for glaciologists and as similar instruments begin operating on spacecraft exploring icy worlds, a technique once limited to a few isolated core sites on Earth could be poised to transform our understanding of ice across the solar system.

Author Information

David Lilien (dlilien@iu.edu), Indiana University Bloomington; T. J. Young, University of St Andrews, Fife, Scotland; Benjamin Hills, Colorado School of Mines, Golden; Tamara Gerber, Université de Lausanne, Lausanne, Switzerland; and Matthew Siegfried, Colorado School of Mines, Golden

Citation: Lilien, D., T. J. Young, B. Hills, T. Gerber, and M. Siegfried (2026), New directions in mapping ice sheet fabrics and flow, Eos, 107, https://doi.org/10.1029/2026EO260154. Published on 14 May 2026. Text © 2026. 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.

When it comes to thriving at high elevation, diminutive plants are always a safe bet. And low-lying vegetation is in fact colonizing higher and higher reaches as the climate changes, new results reveal. Researchers analyzed more than 2 decades’ worth of satellite data and showed that the vegetation line in the Himalayas is moving upward, in some cases by up to several meters per year. These changes have implications for the hydrology of the region and therefore for water resources for the population centers located downstream, the team reported last month in Ecography.

Mountains and People

“If you’re going to understand climate change across the Himalayas, you can’t just look at one location.”

The Himalayas, with their massive stores of frozen water, are part of a region known as the planet’s “Third Pole.” Nearly a billion people rely on water sourced from this area, but the Himalayas aren’t immune to climate change—shifts in temperature and precipitation patterns are causing glaciers to melt and permafrost to thaw, among other effects. “The Himalayan mountains are experiencing a lot of ecosystem changes,” said Ruolin Leng, an Earth scientist who led this new research while at the University of Exeter in the United Kingdom. She currently works at H2Tab, a wellness company.

And while the macroscopic effects of climate change in mountainous regions—the melting of the aforementioned glaciers, for example—have been readily studied, shifts in vegetation are often overlooked, said Leng. That’s a problem because plant cover affects everything from soil moisture levels to water runoff to the albedo of the planet’s surface, all of which have consequences for how water moves through the larger system, she said. “It’s a very important factor in the hydrological system.”

Leng and her colleagues focused on six sites, each roughly 40,000 square kilometers in size, in Bhutan, Nepal, and politically disputed areas farther west. Altogether the locales spanned roughly 15° in longitude (about the width of a U.S. time zone). The choice to analyze several locations along an east-west gradient was deliberate, said Stephan Harrison, a climate scientist also at the University of Exeter and a member of the research team. “The western Himalayas are very different from the eastern Himalayas in terms of climate. If you’re going to understand climate change across the Himalayas, you can’t just look at one location.”

Spotting Vegetation from Space

For each of those sites, the researchers mined satellite observations collected from 1999 to 2022 by the NASA/U.S. Geological Survey Landsat program. The researchers focused on visible and near-infrared observations to calculate a metric known as the normalized difference vegetation index (NDVI). Vegetation tends to reflect relatively little visible light while reflecting much more near-infrared light, and that fact can be exploited to infer the presence of vegetation in remote sensing data, said Karen Anderson, a remote sensing scientist at the Environment and Sustainability Institute at the University of Exeter and a member of the research team.

After masking out pixels too obscured by clouds or snow to correctly analyze, Leng and her colleagues calculated the NDVI for each 30- × 30-meter Landsat pixel within their study regions. The team retained pixels with NDVI levels above a minimum threshold and used those data, combined with topography information, to estimate the maximum elevation that was reliably vegetated each year. All six sites exhibited upward trends in the elevations of their vegetation lines over time, the researchers found. A site in central Nepal straddling the country’s northern border recorded the largest changes: From 1999 to 2022, the elevation of its vegetation line rose from roughly 5,520 meters to 5,670 meters, an increase of just under 7 meters per year on average. The five remaining sites all recorded annual upward shifts ranging from about 1 to 6 meters per year on average.

“Broadly speaking, plants are moving up mountains,” said Anderson. But different regions are responding differently, she added. (And while similar results have been previously noted in the Himalayas, not all plant life everywhere is moving up—recent research has shown that some tree lines are in fact moving downslope.)

A Climatic Culprit?

“People neglect the little plants.”

To investigate the potential drivers behind these changes, the team studied correlations with three climatic parameters: temperature, total precipitation, and snow depth. These data came from the European Centre for Medium-Range Weather Forecasts reanalysis dataset, which has a spatial resolution of roughly 30 kilometers.

Leng and her collaborators found that their site with the fastest-changing vegetation line also recorded the most rapid increase in snow depth over time. These two changes might therefore be linked, but more work is needed, Anderson admitted. “We haven’t addressed the causal link here. We’ve simply looked for patterns.”

There’s also a significant mismatch in the spatial resolution of the team’s meteorological data and their Landsat data, said Trevor Keenan, an ecosystem scientist at the University of California, Berkeley not involved in the research. Such a discrepancy can be particularly problematic in complex landscapes like mountain ranges because the coarse meteorological data might not be capturing the true microclimates that are bound to persist in such places, he said. “With heterogenous terrain and large elevational gradients, you really need that microclimate information.”

Sagarmatha National Park in Nepal, home to Mount Everest, is also host to rhododendron forests like this one. Credit: Peter Prokosch, CC BY-NC-SA 2.0

Anderson knows the geographical complexity of the Himalayas firsthand—in 2017 and 2022, she and other scientists conducted fieldwork in Nepal that informed this research. Those trips were a special opportunity to see plants like dwarf rhododendron thriving in tough conditions, she said. And it was a good lesson in appreciating some of the most diminutive members of the plant kingdom, Anderson added. “People neglect the little plants.”

—Katherine Kornei (@KatherineKornei), Science Writer

Citation: Kornei, K. (2026), Vegetation moves upslope across the Himalayas, Eos, 107, https://doi.org/10.1029/2026EO260149. Published on 14 May 2026. Text © 2026. 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’ Vox is a blog from AGU’s Publications Department.

Often times when we think “scientist,” we picture a white lab coat, a pipette. Or, a marine biologist covered in seaweed samples. A geologist with dusty knees and hands full of rock fragments. Endless blue gloves. What we may not always picture is our favorite professors, colleagues, or even students advocating for science to policy makers.

Federal policy decisions have a direct impact on science funding, research priorities, and the role of science in society.

Federal policy decisions have a direct impact on science funding, research priorities, and the role of science in society, and the AGU community has a critical role to play in those conversations. Each year, AGU’s Science Policy and Government Relations (SPGR) team organizes and hosts Congressional Visit Days to connect Earth and space scientists to their elected officials. As a member of AGU’s scientific publications team, I joined the April 21-22 Days of Action to learn about the bills currently impacting our workforce and research, how to craft messages that both speak to our personal experiences, and to ask our elected officials to advocate with and for us.

As a D.C. native, I grew up in close proximity to the power of science, the alphabet agencies, NOAA, NASA, NIH, and USDA. Institutions where the best and brightest were given the resources and support to learn, record, and disseminate knowledge on behalf of our country. In my current role with AGU as a non-profit publisher, I took to the Hill to share my experiences on the publishing and academic peer-review landscape. My role allows me to see first-hand how budget cuts and shifting attitudes have impacted critical programs at the agencies named above. This Days of Action event brought together 58 participants with one goal: to share personal stories that related to four bills:

1. The RESEARCHER Act (H.R. 3054, S.1664)- addresses graduate student financial instability.
2. KEEP STEM Talent Act (H.R. 2627, S.1233)- strengthens the U.S. scientific workforce by making it easier for skilled international STEM graduates from U.S. universities to stay in the U.S.
3. Protect America’s Workforce Act (H.R.2550 passed House, S.2837)- seeks to protect the U.S. federal scientific workforce by restoring collective bargaining (union) rights.
4. Scientific Integrity Act (H.R.1106)- protects the rights of U.S. federal scientists and researchers by safeguarding scientific integrity in federal research and decision-making.

Two participants spoke on their experiences meeting with elected representatives and uniquely captured just how closely the Earth and spaces sciences touch all of our lives.

Sheila Baber, an early career scientist with The University of Maryland, felt compelled to join due to “the uncertain future for myself, my peers, and the American scientific enterprise.” She noted, “It has been especially difficult to witness the deteriorating relationship between scientists, decision makers, and the public. This past year, with its rapidly changing federal landscape, has been a wakeup call to re-engage and remind the public of how science research gives back to the community.”

Ryan Haupt, long-time AGU member and the Executive Director at National Youth Science Academy, with a 10-year track record of geoscience advocacy, emphasized the importance of building relationships with elected officials. “Regardless of party affiliation, I want those staffers to know that when they meet with me or any other AGU member, they will get honest and informed feedback from folks who are truly passionate about our fields,” Ryan told me. “[Experts who can speak to how current bills] impact issues like improved financial support for graduate students, helping international students stay in the US to join the STEM workforce, and protecting funding for federal science agencies and the folks who work for them.”

As a participant myself, I joined the Maryland group to meet with Senator Chris Van Hollen’s office. Van Hollen and I met briefly at the Stand Up for Science March in 2025. His voting track record indicates a long-standing commitment to the scientific community, and he champions bills that support funding federal agencies like NOAA.

(left to right) The Maryland group, McKay Porter, Andrew Inglis, Nour Rawafi, Stephen Jascourt, and Emille Beller met with Senator Chris Van Hollen’s staffer, Leo Confalone. Credit: Beth Bagley, AGU

Finding and discovering the best and the brightest means funding, protecting, and supporting the best and the brightest.

Working in scientific publishing has allowed me to peer behind lab doors, into research vessels sailing through the Arctic, and into the entire ecosystem that is peer-reviewed research. A system that relies on incoming eager students, federal grant funding, consortium agreements between the biggest institutional libraries and the biggest publishing houses in the country, scientific integrity, and future, stable career opportunities. Finding and discovering the best and the brightest means funding, protecting, and supporting the best and the brightest.

Open, accessible science builds and supports both public trust and future scientific advancements. As the world widens and we are all met with increased access to studies, content, and news, scientific storytelling and literacy have never been more important for ensuring public trust. Transparency from the lab and from the field to published output allows for data to be discussed, fact-checked, and reused to support future scientific discovery. Days of Action demonstrates that we have a unique role to play in supporting the health, safety, and future of our country. If you feel called to get involved, please see resources available from SPGR.

Ryan reminds us, “There are lots of ways to participate in our democracy… find where you can best serve as a leader…don’t try to do it all, but try to do something.”

—Emille Beller (ebeller@agu.org, 0009-0009-7274-0706), Senior Program Coordinator, AGU Publications

Citation: Beller, E. (2026), The impact of advocacy: American Geophysical Union’s Days of Action, Eos, 107, https://doi.org/10.1029/2026EO265020. Published on 14 May 2026. 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 © 2026. 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.

New evidence from the Natural Hazards Commission – Toka Tū Ake (NHC) shows that landslides are now New Zealand’s most costly natural hazard.

New Zealand is a country that is prone to a range of natural hazards. Located on a series of major fault systems, earthquakes cause high levels of loss. The country is also volcanically active, with occasional tragedies. Heavy rainfall brings floods.

To share the cost of these perils, following the 1942 Wairarapa earthquakes, the New Zealand government established the Earthquake Commission (EQC) in 1945, initially focusing on earthquakes and war damage, but subsquently expanded to cover other natural hazards.

In the subsequent years, the EQC has evolved into the Natural Hazards Commission – Toka Tū Ake (NHC), with a purpose “to reduce the impact of natural hazards on people, property, and the community”. Essentially it operates as a financial pool, with home owners paying a levy on top of their insurance to generate the fund. In the event of a loss, the fund pays for the rebuild costs up to a cap (currently NZ$300,000); the remainder is then covered by the property’s insurance. Claims are funded directly from the pool, with reinsurance cover and ultimately a government guarantee in place to ensure that there are sufficient funds.

In reality, NHC does much more than this, acting to manage and settle claims, and to understand the range of hazards to which New Zealand is prone.

In the last few days, a range of media outlets in New Zealand have been reporting new data from NHC about losses from natural hazards in New Zealand. This is the headline from 1News:

“Landslides are New Zealand’s most expensive natural hazard – and new data reveals a sharp rise in damage claims and growing risks to homes, infrastructure and communities.”

In total, since 2021 NHC has received 13,000 landslide claims and has paid out NZ$322 million (US$191 million). New Zealand is seeing an abrupt increase in landslide losses, driven primarily by increasingly frequent high magnitude rainfall events. NHC is urging property owners to undertake preventative maintenance and to be aware of the limitations of EQC cover.

Here be landslides – typical landslide-prone terrain in New Zealand.

In common with many other places, these landslide hazards represent a major challenge to New Zealand. The landscape has many dormant landslides that are being reactivated by these increased rainfall events, and many new failures are also occurring. But, generating reliable risk maps for landslides remains a major challenge. This needs to be a major research focus in the coming years. It will require better understanding of triggering events (rainfall and earthquakes primarily); of the initiation processes within the slope; of runout / debris mobility; and of vulnerability and consequent losses. It is probably true to say that in all of these areas, landslide research lags behind that of earthquakes and floods, primarily because of a lack of long term investment.

In many countries, landslides are not an insured risk for this reason. On its own, this will be a major challenge that must be addressed. For those countries in which landslides are insured, we need quickly to get up to speed.

Return to The Landslide Blog homepage Text © 2026. The authors. CC BY-NC-ND 3.0
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