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As hot, dry and disastrous as the last few years have been, it appears that the chaos caused by a warming planet is just getting started.

A new study led by University of Wisconsin-Oshkosh geologist Timothy Paulsen and University of Colorado Boulder thermochronologist Jeff Benowitz advances the understanding of the geologic history of Transantarctic Mountains bedrock, with implications for understanding the evolution of landscapes lying beneath the ice sheets covering Antarctica.

Seasonal fluctuations to the climate are the dominant influence globally in shaping the changes to the size of lake surfaces, according to a new study.

A study led by Prof. Tao Hui from the Xinjiang Institute of Ecology and Geography of the Chinese Academy of Sciences has revealed that natural environmental factors are the predominant drivers of desertification across Central Asia. This study was published in Catena.

The National Oceanic and Atmospheric Administration is predicting an above-average Atlantic hurricane season from June 1 through Nov. 30.

The textbook explanation of how hailstones grow goes something like this: Nuclei collect frozen layers as they are repeatedly lofted up and fall through clouds. But scientists have had hints that this up-down cycle doesn’t always reflect real hailstones’ journeys. Now researchers have revived an old technique to track dozens of hailstones. The new results suggest that many hailstones take simpler paths.

The idea that hailstones grow as they repeatedly rise and fall on repeat arose as a way to explain stones’ alternating layers of different transparencies, said Xiangyu Lin, an atmospheric scientist at Peking University in Beijing and an author on the new study. But scientists don’t have any direct observations of individual hailstones’ paths in clouds because the severe storms that produce hail are difficult, even dangerous, to observe.

“The vast majority of our understanding of how hail grows has come from numerical modeling,” said Matthew Kumjian, an atmospheric scientist at Pennsylvania State University who wasn’t part of the study. The new research is “a nice piece of experimental evidence” to validate those models, he said.

“Over the past 8 years, we have collected more than 3,000 hailstones.”

At a seminar at Peking University in 2018, Kumjian showed a simple arcing trajectory—rather than a yo-yoing one—for simulated hailstones. Seeing those results, one of Lin’s colleagues at Peking University, atmospheric scientist Qinghong Zhang, wondered whether she could find real hailstones that followed a similar path. That year she started collecting hailstones, using social media to ask the public to save the icy orbs. “Over the past 8 years, we have collected more than 3,000 hailstones,” she said.

To trace the hailstones’ trajectories, the team turned to stable isotopes. At lower altitude, the ice that forms on hailstones tends to have a greater concentration of heavier isotopes of hydrogen and oxygen than the ice that forms higher up. Researchers can measure the ratio of heavy and light isotopes in a layer, providing a postmark of sorts for the altitude at which the ice originated.

The scientists analyzed 27 hailstones from nine different storms spread across eastern China. They sliced each stone in half to reveal its layers. Then they cut the hailstones down layer by layer, so they could melt each layer and measure its isotopes. To find the link between isotope concentrations and height in a storm cloud, the team used temperature, humidity, and pressure data from weather balloons that floated through the atmosphere near each storm.

Hailing from Where?

The isotopes showed that of the hailstones they analyzed, only one had more than one upward flight segment. A few hailstones grew at a relatively constant altitude, and 16 either rose or fell steadily as they grew.

Eight hailstones ascended once before falling to the ground. These eight hailstones were significantly larger than the other stones, Lin said. Hailstones primarily grew between −10°C and −30°C, the team found. With their up-and-down path, these eight stones seem to have spent more time in that zone, causing them to grow larger than others.

Many hailstones are not perfect spheres. Credit: Xiangyu Lin

Scientists used stable isotope analysis on hailstones some 50 years ago, but the technique fell out of favor, Kumjian said. Many of those early studies analyzed a small number of stones from few storms or sometimes a single storm. The new study is “bringing back this old type of analysis with modern methods,” he said.

But the analysis required assumptions that might cloud results. For instance, updrafts can mix air from different altitudes, Kumjian said. That can affect the isotopes in a hailstone’s layers.

Scientists are still exploring questions about hail across a range of scales from stone to storm. Though researchers know what sorts of storms can produce damaging hail, it’s hard to predict which will rain down baseball-sized stones or where exactly hail will fall. Meanwhile, the physics of hailstones’ growth is tricky. Researchers typically model stones as perfect spheres—a far cry from the bumpy lumps that fall from the sky. But those shapes affect how fast hail falls and the damage it can produce, Kumjian said.

“It’s a very exciting time in the hail world. We’re going to learn a lot in the coming years.”

Researchers are using modeling, radar observations, and isotope studies such as this one to improve forecasts. Hail can knock out crops, damage structures, and shatter solar panels. Even 10 minutes of warning is enough for people to move cars and prevent damage, Zhang said.

Kumjian is part of a team that is launching instrumented Styrofoam spheres into clouds that could provide insights on actual paths taken by stones. Zhang’s team is continuing to study isotopes in layers, now looking at larger stones that formed in storms over Italy. “It’s a very exciting time in the hail world,” Kumjian said. “We’re going to learn a lot in the coming years.”

—Carolyn Wilke (@CarolynMWilke), Science Writer

Citation: Wilke, C. (2025), Isotopes map hailstones’ paths through clouds, Eos, 106, https://doi.org/10.1029/2025EO250206. Published on 30 May 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

New research reveals the amount of carbon dioxide released by trees into the atmosphere under a warming climate could be considerably less than currently predicted.

Author(s): S. X. Hu, N. R. Shaffer, B. Arnold, K. A. Nichols, V. V. Karasiev, S. Zhang, and V. N. Goncharov

Recent experimental demonstrations of ignition and target gain in inertial confinement fusion (ICF) have stimulated interest in exploring the fundamental physics of violent deuterium-tritium (DT) burn in high-gain ICF targets. A significant DT-burn fraction is a necessary condition for high energy g…

[Phys. Rev. E 111, L053202] Published Fri May 30, 2025

Seismological research is directly related to the incubation, occurrence, and evolution of earthquakes. Scientists seek to reveal potential earthquake precursors by monitoring the stress state of fault zones, thus providing bases for earthquake prevention and mitigation.

Sixty-seven extreme heat events have occurred since May 2024. All of these events—including a deadly Mediterranean heat wave in July 2024, an unprecedented March 2025 heat wave in central Asia, and extreme heat in South Sudan in February 2025—broke temperature records, caused major harm to people or property, or did both.

According to a new analysis, each of these extreme events was made more likely by climate change. The number of days with extreme heat is now at least double what it would have been without climate change in 195 countries and territories. Climate change added at least an extra month of extreme heat in the past year for 4 billion people—half the world’s population. 

“The numbers are staggering.”

“There’s really no corner of the globe that has been untouched by climate-driven extreme heat,” said Kristina Dahl, a climate researcher at the climate change research and communication nonprofit Climate Central who was part of the report team. “Half the world’s population is experiencing an extra month of extreme heat. The numbers are staggering.”

The authors of the report say it serves as a stark reminder of the dangers of climate change and the urgent need for better early-warning systems, heat action plans, and long-term planning for heat events across the globe. 

The report was created by scientists at Climate Central; World Weather Attribution, a climate research group; and the Red Cross Climate Centre. 

More Frequent Heat

In the new report, scientists calculated the number of days between 1 May 2024 and 1 May 2025 in which temperatures in a country or territory were above 90% of the historical temperatures from 1991 to 2020. Then, they analyzed how many of these extreme heat days were made more likely by climate change using the climate shift index, a methodology developed by Climate Central that compares actual temperatures to a simulated world without human-caused climate change. 

The team found that climate change made extreme heat events more likely in every country.

Over all the countries and territories, climate change added the greatest number of extreme heat days to the Federated States of Micronesia (57 days), and Aruba had the most extreme heat days in total over the past year, 187 days. The report’s authors estimate that in a world without climate change, Aruba would have experienced just 45 days of extreme heat.

Other Caribbean and Oceanic islands were among the countries and territories most strongly affected by climate change. People in the United States experienced 46 days of extreme heat, 24 of which were added by climate change. 

The authors of the report calculated the number of extreme heat days added by climate change in the past year. Credit: World Weather Attribution, Climate Central, and Red Cross Red Crescent Climate Centre

Of the 67 extreme heat events that occurred in the past year, the one most influenced by climate change was a heat wave that struck Pacific islands in May 2024. Researchers estimated the event was made at least 69 times more likely by climate change. 

The findings are not a surprise to Nick Leach, a climate scientist at the University of Oxford who was not involved in the report. “We’ve understood the impact of climate change on temperature and extreme heat for quite some time…[including] how it’s increasing the frequency and intensity of extreme heat,” he said. Research has consistently shown that heat events on Earth are made more likely, more intense, and longer lasting as a result of climate change. 

“Only comprehensive mitigation, through phasing out fossil fuels, will limit the severity of future heat-related harms.”

Leach said the new report gives a good overview of how climate change is influencing heat waves worldwide. However, defining extreme heat as temperatures above the 1991–2020 90th percentile creates a relatively broad analysis, he said. Studies using a more extreme definition of extreme heat may be more relevant to the impacts of extreme heat, and studies estimating those impacts are typically more policy relevant, he said.

The report’s authors chose the 90% threshold because heat-related illness and mortality begin to increase at those temperatures, Dahl said. 

Taking Action on Heat Waves

For rising global temperatures, “the causes are well known,” the report’s authors wrote. Burning of fossil fuels such as coal, oil, and gas has released enough greenhouse gases to warm the planet by 1.3°C (2.34°F; calculated as a 5-year average); 2024 marked the first year with average global temperatures exceeding 1.5°C (2.7°F) above preindustrial temperatures.

“Only comprehensive mitigation, through phasing out fossil fuels, will limit the severity of future heat-related harms,” the authors wrote.

Extreme heat puts strain on the human body as it tries to cool itself. This strain can worsen chronic conditions such as cardiovascular problems, mental health problems, and diabetes and can cause heat exhaustion and heat stroke, which can be deadly. Extreme heat is particularly dangerous for already-vulnerable populations, including those with preexisting health conditions, low-income populations lacking access to cool shelter, and outdoor workers. 

Heat Action Day on 2 June, hosted by the International Federation of Red Cross and Red Crescent Societies, raises awareness of heat risks across the globe. This year, the day of action will focus on how to recognize signs of heat exhaustion and heat stroke. Dahl recommends using the Centers for Disease Control and Prevention tips on heat and health to stay safe. “Most heat-related illness and death is preventable,” she said.

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

Citation: van Deelen, G. (2025), Climate change made extreme heat days more likely, Eos, 106, https://doi.org/10.1029/2025EO250208. Published on 30 May 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

SummaryWe revisit the budget of 20th century true polar wander (∼1°/Myr in the direction of 70°W) using a state-of-the-art adjoint-based reconstruction of mantle convective flow and predictions of ongoing glacial isostatic adjustment that adopt two independent models of Pleistocene ice history. Both calculations are based on a mantle viscosity profile that simultaneously fits a suite of data sets related to glacial isostatic adjustment (Fennoscandian Relaxation Spectrum, post-glacial decay times) and a set of present-day observations associated with mantle convection (long-wavelength gravity-anomalies, plate motions, excess ellipticity of the core-mantle boundary). Our predictions reconcile both the magnitude and direction of the observed true polar wander rate, with convection and glacial isostatic adjustment contributing signals that are 25-30% and ∼75% of the observed rate, respectively. The former assumes that large-scale seismic velocity heterogeneities are purely thermal in origin, and we argue that our estimate of the convection signal likely represents an upper bound due to the neglect of hypothesized compositional variations within the large low shear velocity provinces in the deep mantle.

In the remote and hostile realm of the Amundsen Sea Embayment, West Antarctica, powerful winds known as low-level jets (LLJs) race over its coastal regions, including both the Thwaites and Pine Island ice shelves and the open ocean. These previously unknown atmospheric forces could hold the key to understanding—and predicting—the alarming melt of two critical glaciers: Pine Island and Thwaites, the latter ominously called the "Doomsday Glacier" for its potential to unleash catastrophic sea-level rise.

Several key moments in Earth's history help us humans answer the question "How did we get here?" These moments also shed light on the question "Where are we going?" and offer scientists deeper insight into how organisms adapt to physical and chemical changes in their environment.

During the final week of summer in 2021, Hurricane Ida emerged from the Gulf of Mexico, turned almost directly northeast and swept through the South en route to Pennsylvania, New York, New Jersey and Connecticut.

A new study with ETH Zurich finds that if global warming exceeds the Paris Climate Agreement targets, the non-polar glacier mass will diminish significantly. However, if warming is limited to 1.5°C, at least 54% could be preserved—more than twice as much ice as in a 2.7°C scenario.

The Atlantic Meridional Overturning Circulation (AMOC) serves as the Atlantic Ocean's conveyor belt, transporting warm water north toward the Arctic Circle and returning cold, dense water back to the tropics. Nearshore areas off Greenland are critical sites in AMOC, influencing the redistribution of heat and nutrients around the world.

Earthquakes create ripple effects in Earth's upper atmosphere that can disrupt satellite communications and navigation systems we rely on. Nagoya University scientists and their collaborators have used Japan's extensive network of Global Navigation Satellite System (GNSS) receivers to create the first 3D images of atmospheric disturbances caused by the 2024 Noto Peninsula Earthquake.

The Atlantic meridional overturning circulation, commonly referred to as the "AMOC," is a system of ocean currents confined to the Atlantic basin that plays a crucial role in regulating Earth's climate by transporting heat from the Southern to the Northern Hemisphere. The AMOC also modulates regional weather, from the mild summers in Europe to the monsoon seasons in Africa and India.

Replanting forests can help cool the planet even more than some scientists once believed, especially in the tropics. But even if every tree lost since the mid-19th century is replanted, the total effect won't cancel out human-generated warming. Cutting emissions remains essential.