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SummarySeismic signals generated by near-surface explosions, with sources including industrial accidents and terrorism, are often analysed to assist post-detonation forensic characterisation efforts such as estimating explosive yield. Explosively generated seismic displacements are a function of, amongst other factors: the source-to-receiver distance, the explosive yield, the height-of-burst or depth-of-burial of the source and the geological material at the detonation site. Recent experiments in the United States, focusing on ground motion recordings at distances of <15 km from explosive trials, have resulted in empirical models for predicting P-wave displacements generated by explosions in and above hard rock (granite, limestone), dry alluvium, and water. To extend these models to include sources within and above saturated sediments we conducted eight explosions at Foulness, Essex, UK, where ∼150 m thicknesses of alluvium and clay overlie chalk. These shots, named the Foulness Seismoacoustic Coupling Trials (FSCT), had charge masses of 10 and 100 kg TNT equivalent and were emplaced between 2.3 m below and 1.4 m above the ground surface. Initial P-wave displacements, recorded between 150 and 7000 m from the explosions, exhibit amplitude variations as a function of distance that depart from a single power-law decay relationship. The layered geology at Foulness causes the propagation path that generates the initial P-wave to change as the distance from the source increases, with each path exhibiting different amplitude decay rates as a function of distance. At distances up to 300 m from the source the first arrival is associated with direct propagation through the upper sediments, while beyond 1000 m the initial P-waves are refracted returns from deeper structure. At intermediate distances constructive interference occurs between P-waves propagating through the upper sediments and those returning from velocity-depth gradients at depths between 100 and 300 m. This generates an increase in displacement amplitude, with a maximum at ∼800 m from the source. Numerical waveform modelling indicates that observations of the amplitude variations is in part the consequence of high P- to S-wave velocity ratios within the upper 150 m of saturated sediment, resulting in temporal separation of the P- and S-arrivals. We extend a recently developed empirical model formulation to allow for such distance-dependent amplitude variations. Changes in explosive height-of-burst within and above the saturated sediments at Foulness result in large P-wave amplitude variations. FSCT surface explosions exhibit P-wave displacement amplitudes that are a factor of 22 smaller than coupled explosions at depth, compared to factors of 2.3 and 7.6 reported for dry alluvium and granite respectively.

SummaryIntermittent fluid injection aims at inferring and steering hydraulic transmissivity and has become an integral part of reservoir stimulation techniques. Modeling the poroelastic response of such pumping operations poses new challenges with respect to the hydromechanical coupling. This is because when a fluid pressure perturbation is introduced in the pore space of a deformable porous rock, it will induce a stress perturbation in the solid phase and this is accompanied by pore boundary motion. Within the limits of quasi-static linear poroelasticity, we analyze the macroscopic signatures of pore boundary motion during injection, i.e., when the rock frame is mechanically loaded, and after injection stop, i.e., when pore boundaries tend to relax back into equilibrium. We show that there is a pumping sequence that allows to harness the energy associated with pore boundary motion accumulated during the frame-loading cycle. Our results foster the need to distinguish how pressure diffusion in poroelastic solids proceeds: either fluid transport is of compressible or incompressible nature and the respective diffusion constant depends on undrained or drained poroelastic moduli.

SummaryThermal properties such as thermal conductivity (TC), thermal diffusivity (TD), and specific heat capacity (SHC) are essential for understanding and modelling the subsurface thermal field. In sedimentary basins, these parameters play a key role in characterizing the present-day thermal state and predicting its evolution, for example, in response to future geo-energy utilizations. Given the wide range of potential geo-energy utilizations and the frequent lack of sufficient sample material, many studies have focused on developing accurate prediction approaches. Machine learning (ML) offers promising non-linear statistical methods to enhance the mapping of interrelations between standard geophysical well-log readings and thermal rock properties. In this study, we introduce an open-access tool for computing profiles of thermal rock properties from standard geophysical borehole logging data, building upon and extending previous petrophysical studies. The tool employs various machine-learning approaches trained on large, physically modelled synthetic datasets that account for mineralogical and porosity variability across major sedimentary rock groups (clastic rocks, carbonates, and evaporates). It establishes functional relationships between thermal properties and different combinations of standard well-log data, including sonic velocity, neutron porosity, bulk density, and the gamma-ray index. We trained four different models including linear regression, AdaBoost, Random Forest, and XGBoost using 80 per cent of the synthetic group data for model development, including training and hyperparameter tuning through cross-validation. The remaining 20 per cent was held out as an independent test set for statistical validation, feature recognition, and input variable importance analysis. A total of 15 input log combinations (including all one, two, three, and four well-log configurations) were evaluated across four machine learning models (linear regression, AdaBoost, Random Forest, and XGBoost), resulting in 180 trained models. The model's predictive accuracy and reliability were further evaluated against independent laboratory drill-core measurements reported in recent studies. Our results indicate that the best-performing predictive models vary depending on the available log-combinations. However, XGBoost frequently outperforms other models in sedimentary rocks. When at least two well logs are provided as input variables, the best-performing models predict thermal conductivity with an uncertainty below 10 per cent relative to borehole validation data (with laboratory-measured thermal conductivity). In most tested model cases and for most input log combinations, predictive errors for thermal conductivity range between 10 and 30 per cent at the (point measurement) sample scale (cm to half a meter). However, when averaged over geological formations or borehole intervals (tens to thousands of meters), the accuracy of thermal-conductivity predictions improves significantly, with uncertainties of the interval mean conductivity dropping below 5 per cent for large intervals. For specific heat capacity, prediction accuracy for the best-performing models at the measurement scale is typically better than 5 per cent. Thermal diffusivity reflects a larger variation, accumulating the uncertainties from conductivity and heat capacity. The presented log-based Python prediction tool provides an automated means to compute thermal parameters using the most suitable ML model for given well-log inputs, facilitating enhanced thermal characterization in sedimentary settings. This has practical relevance for geothermal or hydrocarbon exploration, or subsurface storage projects.

The Southwest United States is currently facing its worst megadrought of the past 1,200 years. According to a recent study by the University of Texas at Austin, the drought could continue at least until the end of the century, if not longer.

Between July 3 and 6, Texas Hill Country experienced catastrophic flash flooding along the Guadalupe River system. The floods claimed at least 130 lives, with over 96 fatalities in Kerr County alone. More than 160 people were missing as of July 12, including children attending camps along the river.

Industrial whaling was historically a grisly affair enacted with brutal efficiency. With an eye to harpooning as many whales as possible, whalers created detailed records intended to inform and improve future expeditions.

Those records, stretching back more than a century, provide rich datasets that scientists have used to answer questions about our planet’s past, including how sea ice surrounding Antarctica ebbed and flowed in the decades before satellites enabled continuous monitoring.

“I find it a paradox. We decimated them; now, they’re helping us to do a better job for our future projections.”

In a study published earlier this year in Environmental Research: Climate, a team of cetologists, oceanographers, and climate scientists dug deep into those records and used them to show that contemporary climate models overestimate the historic extent of sea ice in the Southern Ocean.

The group relied specifically on data from humpback whaling expeditions because that species tends to skirt along the ice edge in summer, skimming krill fed in turn by algal mats that form along the underside of the ice as it thins and retreats. This behavior makes the locations of humpback harvests a useful proxy for how far north sea ice could have reached.

“I find it a paradox,” said oceanographer Marcello Vichi of the University of Cape Town in South Africa. “We decimated them; now, they’re helping us to do a better job for our future projections.” Vichi is the first author of the new study.

Icy Estimation

Accurately estimating the extent of sea ice is important for modeling because ice reflects sunlight, said Marilyn Raphael, a physical geographer at the University of California, Los Angeles, who often focuses her research on Antarctic sea ice but was not involved with the new study.

“If it doesn’t do that reflection, the large-scale [latitudinal] temperature gradient changes,” Raphael explained, “and when the temperature gradient changes, the wind changes. And when the wind changes, the climate changes.”

Sea ice also insulates parts of the Southern Ocean, limiting how much heat the water absorbs from the atmosphere.

How climate models input the historical extent of sea ice shapes how they account for Earth’s energy balance prior to the onset of climate change. More accurate historic inputs also have implications for modeled predictions about the extent of sea ice in the future.

“If you can’t get it right when you know what happened,” Raphael said, “then you’ve got to worry about if you’ll get it right when you don’t know what will happen.”

Using Catch Data to Constrain Sea Ice

Vichi and his colleagues used data acquired from the International Whaling Commission, which recorded the locations of more than 215,000 humpback catches over the first half of the 20th century, with latitude and longitude logged to the nearest degree.

They focused their study on the 1930s, a period during which whalers logged consistently high catch counts for each month of the Antarctic summer (November through February), when humpbacks feed as ice retreats. This narrowed scope left the researchers with around 13,500 records to work with, of which more than 97% had trustworthy location data.

The team compared the catch locations with the climate models that are best tuned to match today’s satellite observation data.

All the models, they found, consistently overestimate the historic extent of sea ice by an average of about 4° latitude. In some places, Vichi added, they overshoot the ice edge suggested by the whaling records by 10°.

“It’s really great to examine historical data to find ways of understanding a complex system better, especially a complex system that we don’t have a lot of observations on.”

Vichi and his colleagues don’t yet know for certain what drives the discrepancy they found. One possible explanation may be that the nature of how ice forms and behaves in the Southern Ocean has shifted, potentially entering a new regime around the 1960s.

Scientists are working with fewer than 50 years of satellite observations when it comes to sea ice, “so if there are large cycles that happen, we don’t know if that 50 year period is representative of the whole,” said climatologist Ryan Fogt of Ohio University in Athens, who wasn’t involved in the study.

Given the dearth of direct observations, this gap can be filled only with proxies like catch data. Using indirect data is an approach both Raphael and Vichi acknowledge has limitations but is crucial for better understanding the nuances of climate change.

“I think using the whaling records is a good idea,” Raphael said. “It’s important to use all the information we have to see how it matches.”

“It’s really great to examine historical data to find ways of understanding a complex system better, especially a complex system that we don’t have a lot of observations on,” said Fogt, who has also worked with historical records (though not whale catch data) to reconstruct historic sea ice extent around Antarctica. “So even though they’re imperfect, these historical sources, they have value.”

—Syris Valentine (@shapersyris.bsky.social), Science Writer

Citation: Valentine, S. (2025), Whaling records can help improve estimates of sea ice extent, Eos, 106, https://doi.org/10.1029/2025EO250251. Published on 15 July 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.

A strange planet orbiting a distant star may be even weirder than we realized. Already thought to have “iron rain” and an unusual polar orbit, this ultrahot Jupiter might also have begun life far away from its star before diving into a tight 30-hour orbit.

The planet, WASP-121b, or Tylos, is about 850 light-years from Earth and was discovered in 2015. Observing the planet in October 2022 with the James Webb Space Telescope (JSWT), researchers found it hosted a surprising amount of methane and silicon monoxide. Their observations mark the first time silicon monoxide has been conclusively found on another world.

“Something weird happened dynamically in its past.”

The presence of methane and silicon monoxide, researchers say, might mean WASP-121b initially formed much farther from its star—as far away as 30 astronomical units, about the same distance Neptune lies from our Sun. (One astronomical unit is the average distance between the Sun and Earth.) The findings were published in Nature Astronomy and The Astronomical Journal.

“Something weird happened dynamically in its past,” said Tom Evans-Soma, an astronomer at the University of Newcastle in Australia and lead author of the Nature paper. “And it may be a big factor in how it moved from far out to close in.”

Iron Rain

Hot Jupiters are a class of gas giant planets that orbit extremely close to their stars and have temperatures exceeding 1,500 K (2,200°F). Ultrahot Jupiters are even closer and hotter, sometimes reaching temperatures above 2,000 K (3,100°F).

WASP-121b is one such ultrahot world, orbiting its star (WASP 121) within 2 times the star’s radius. At this proximity, the planet is tidally locked to the star, the way the Moon is to Earth, so the same face always points to the star. Atmospheric temperatures on WASP-121b can reach more than 3,000 K (4,900°F) on the dayside and 1,100 K (1,500°F) on the nightside.

This discrepancy in temperature may help explain the concept of iron rain on WASP-121b. Metals are likely to vaporize on the fiery dayside, and as these particles blow to the nightside, the drop in temperature creates conditions for droplets of liquid metal to form and fall from the planet’s atmosphere. “The nightside temperatures drop low enough for a whole bunch of these materials to condense,” possibly within seconds, said Evans-Soma.

The planet’s proximity to its star has also stretched the world into an oblong shape, and it orbits its star in a strange 90° orientation, almost pole to pole above and below the star. The planets of our solar system, by comparison, orbit in a flat plane.

A Distant Origin

These characteristics alone had already painted WASP-121b as an unusual world, but the latest observations further add to its mystery.

The researchers used JWST to observe the planet for 40 hours and pick apart its light, revealing the presence of water, carbon monoxide, and silicon monoxide on the dayside. These compounds may have been pulled from the nightside by a powerful equatorial jet with wind speeds of up to 10 kilometers (6 miles) per second.

The team detected methane in the planet’s nightside—a surprising result because methane shouldn’t survive WASP-121b’s high temperatures.

The team also detected methane in the planet’s nightside—a surprising result because methane shouldn’t survive WASP-121b’s high temperatures at all. “People have been looking for methane in exoplanets, but generally focusing on much cooler planets,” said Evans-Soma.

The presence of methane suggests the planet has a source of the compound replenishing its atmospheric supply. The team thinks the source might be trapped methane pulled up from the planet’s interior by strong convection currents.

The presence of methane might also point to WASP-121b forming much farther from its star. At a greater distance, icy pebbles of the methane were more abundant. Here, too, the gas giant may have consumed 21 Earths’ worth of rocky material during its formation, which would explain the presence of silicon.

A Starward Migration

Richard Booth, a planet formation expert at the University of Leeds in the United Kingdom who was not involved in the research, said that in general, scientists think hot Jupiters migrate inward over time. It is unlikely the planets formed close to their stars, he explained, because the stars’ gravity would have been too strong for planets to coalesce.

“Hot Jupiters definitely don’t form in situ,” said Booth.

But finding “evidence for migration is hard,” he continued, because migration can happen quickly (at least on planetary timescales)—in just millions or even thousands of years.

The WASP-121 system is thought to have formed about 1.1 billion years ago, with its migration possibly happening as a result of a gravitational nudge from a passing star or other planets in the system. Such a nudge might also explain the planet’s odd orbit.

Future work could tell us how this seemingly strange exoplanet compares with other ultrahot Jupiters. “It’s not clear that it is particularly unusual,” said Evans-Soma. “It just happens to be one of the planets we can study in really exquisite detail.”

—Jonathan O’Callaghan, Science Writer

Citation: O’Callaghan, J. (2025), This exoplanet may have grown stranger as it journeyed starward, Eos, 106, https://doi.org/10.1029/2025EO250250. Published on 15 July 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.

From more frequent wildfires to rising sea levels, climate change is disrupting ecosystems and upending once-stable weather patterns. One particularly alarming consequence of rising global temperatures is the potential collapse of the Atlantic Meridional Overturning Circulation (AMOC), a conveyor-belt-like system of ocean currents driven by the sinking of cold, salty waters in the North Atlantic.

Author(s): Zekun Xu, Fuyuan Wu, Zhuang Zhao, Shigeo Kawata, and Jie Zhang

Magnetized fusion has been used in various inertial confinement fusion concepts to relax ignition requirements. Strong magnetic fields would induce burning asymmetry, which may be usually harmful to the central ignition schemes. However, it could be utilized in some intrinsically asymmetric ignition…

[Phys. Rev. E 112, 015206] Published Tue Jul 15, 2025

A new paper (Kharismalatri, Gomi & Sidle 2025) in the journal Natural Hazards uses the concepts of the inflow angle and the channel gradient to examine the behaviour of large landslides after failure.

Large landslides in areas with steep terrain that either block the valley or turn into a long runout debris flows are an increasing problem globally as the impacts of climate change accelerate. A key question for any large, potentially unstable slope is whether it will block the valley or transition into a long runout flow. Neither is good, clearly, but the risks and management approaches differ.

There is a very interesting paper (Kharismalatri, Gomi & Sidle 2025) in the journal Natural Hazards that uses a database of 188 large landslides from around the world to examine this issue. The paper has been published open access and using a creative commons licence (hurrah!), so please do take a look.

This diagram, from the paper, explains a key and very interesting metric in the study – the inflow angle:-

Key concepts, including the inflow angle, in the study of large landslides by Kharismalatri, Gomi & Sidle (2025).

There are two key ideas here – one is the inflow angle, which is the angle between the main axis of the landslide and the main axis of the channel, and the other is the channel gradient – the gradient of the river valley into which the landslide is moving, measured using a consistent distance scaled to the landslide length.

The most important diagram in the paper is this one, which shows the inflow angle plotted against channel gradient:-

The relationship between the inflow angle, and the channel gradient , from the study of large landslides by Kharismalatri, Gomi & Sidle (2025).

This is quite remarkable. The inflow angle plays a key controlling role in what happens when the landslide reaches the valley. If that angle is greater than about 60o, the landslide nearly always blocks the valley. If it is less, then it generally turns into a debris flow.

Similarly, if the channel gradient is less than about 10o, the landslide almost always blocks the valley. If it is less, it generally turns into a debris flow.

There are some overlaps, but the number of these cases is remarkably low.

It is also very interesting that there are no cases of landslides with both a high inflow angle and a high channel gradient (i.e. where inflow angle is >60o and channel gradient is >15o). I am not sure why this is the case.

This will be a very useful finding for those who are having to manage developing failures in large slopes. It allows a first order prediction of likely behaviour of the slope upon failure. So, for example, I wrote yesterday about a study of the potential failure of the large landslide at Joshimath in India. It would be interesting to see where on the graph that slope plots – it appears to me that the inflow angle is c.90o?

Reference

Kharismalatri, H.S., Gomi, T. & Sidle, R.C. 2025. Geomorphic thresholds for cascading hazards of debris flows and natural dam formation caused by large landslides. Natural Hazards. https://doi.org/10.1007/s11069-025-07402-0

Return to The Landslide Blog homepage Text © 2023. The authors. CC BY-NC-ND 3.0
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Over the last 3,800 years, agro-pastoral activities have accelerated alpine soil erosion at a pace four to 10 times faster than their natural formation. The history of this erosion has just been revealed for the first time by a research team led by a CNRS scientist.

In the first and only reconstruction of ocean pH ever carried out, new research from the University of St Andrews and the University of Birmingham has discovered that a rapid acidification of oceans, due to a massive and sudden rise in atmospheric CO2, caused a mass extinction event 201 million years ago.

Whether from a forest on fire or gasoline powering a car, organic matter rarely combusts completely: Remnants such as char and soot can persist in the environment for decades. Over time, as physical and biological processes break down the scorched leftovers, some of the carbon they contain leaches into groundwater, lakes, and rivers, eventually making its way to the ocean.

At the dawn of the millennium, a group of eminent scientists began compiling a list of the threats they felt were most likely to impact the world's rocky shorelines over the coming quarter of a century.

A new study published in Proceedings of the National Academy of Sciences solves a long-standing climate mystery: Why don't the records of oxygen isotopes (δ18O) in cave formations like stalagmites—known as speleothems—from central southern China reflect the well-known 100,000-year cycles of ice ages seen in other global climate records? These speleothem δ18O records have long been considered a key indicator of the strength of the Asian summer monsoon, so their failure to show these major climate shifts has puzzled scientists for decades.

Climate change is coming… but what on Earth can we do about it? Scientist Dr. Kimberley Miner has written a guide to riding out the oncoming almighty storm.

A new study from UNC-Chapel Hill reveals that repetitive flooding in North Carolina is far more common and more widespread than previously recognized, with over 20,000 buildings flooding multiple times between 1996 and 2020.

Source: Journal of Geophysical Research: Biogeosciences

When sunlight hits clouds or other atmospheric particles, it scatters and becomes diffuse light. Unlike direct sunlight, diffuse light can reach deeper into shaded plant canopies, where plants have dense, layered leaves. The diffuse-light fertilization effect theory suggests that diffuse light in such environments can promote carbon uptake and influence canopy temperature and evapotranspiration. Prior research suggests that some diffuse light can also boost photosynthesis, but after an optimal point, the overall reduction in total radiation will decrease photosynthesis.

However, diffuse light is not typically measured at ground-based sites. Previous studies used indirect methods to infer its effects on plants, including running computer models and measuring atmospheric properties such as clearness. So questions remained about the optimal amount of this filtered sunlight for vegetation.

Since 2017, the National Ecological Observatory Network (NEON) has collected data on diffuse sunlight, evapotranspiration, and other ecological variables across 32 sites in the continental United States, including forests, grasslands, shrubs, and cultivated crops. Schwartz et al. used the NEON dataset combined with satellite records from the Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) to determine how diffuse sunlight connects to evapotranspiration and net ecosystem exchange, or the carbon exchange between ecosystems and the atmosphere.

Their findings suggested that across NEON sites between 2018 and 2022, evapotranspiration decreased as diffuse radiation increased, and no optimal point was observed, contrary to what previous modeling suggested. Evapotranspiration, the researchers found, may be more strongly affected by available moisture than by either direct or diffuse light.

However, diffuse sunlight did enhance net ecosystem exchange in some locations, including forests and areas with shrub or scrub vegetation. Nineteen of the 32 sites showed a positive net ecosystem exchange response to diffuse light, meaning that more carbon can be absorbed when sunlight is scattered. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2025JG008757, 2025)

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

Citation: Owen, R. (2025), How plants respond to scattered sunlight, Eos, 106, https://doi.org/10.1029/2025EO250249. Published on 14 July 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.

Shoppers may use a plastic bag for only a few minutes before tossing it in the trash. Inefficient waste disposal, however, may allow that bag to find its way into streams and, ultimately, coastal ecosystems. There, plastic pollution can imperil marine plants and animals as well as the economic value of beachfront businesses.

“Plastic bags are designed to be single use. They’re designed to be lightweight. Even if we’re trying to properly manage them, they just get into the environment more easily than other plastics,” said Erin Murphy, ocean plastics science and research manager at the Ocean Conservancy.

“These [plastic bag bans] are effective policies, regardless of the scale of governance in which you implement them.”

While many states and municipalities have plastic bag bans or require fees for customers who want a bag, there is no national policy that aims to reduce the number of plastic bags used in the United States.

But a study published last month in Science shows some promising results: In places with bag bans and fees, the number of plastic bags found on local beaches and shorelines has dropped significantly.

“A lot of the time, communities don’t feel like they can implement policy that will directly impact their communities and directly benefit their communities. This study showed that whether it’s a town or state, these [plastic bag bans] are effective policies, regardless of the scale of governance in which you implement them,” said Murphy, who was not involved in the research.

Analyzing the Trash

Study authors Anna Papp and Kimberly Oremus examined data collected from 45,067 shoreline cleanup events between 2016 and 2023. During these events, organized by the Ocean Conservancy, participants collected trash along a beach and logged their findings into the Trash Information and Data for Education and Solutions (TIDES) database.

Plastic bags are the fifth most common item found during these shoreline cleanups, making up 4.5% of all cataloged trash. (Some of the more unusual items logged include golf balls, Mardi Gras beads, and fake nails.)

Papp and Oremus cross-checked the cleanup data with 182 plastic bag policies around the United States that were enacted between 2017 and 2023. The discrepancy between the dates of the cleanup data (starting in 2016) and the policy data (starting a year later) allowed the researchers to use the 2016 data as a control to evaluate how trends in plastic bag litter may have changed in response to local or state-level regulation.

“Comprehensive data on plastics in the environment can be challenging to find, so the cleanup data offered a new way of measuring plastic bag litter in the environment. This, combined with the wide reach of bag policies in the U.S. in recent years, made our study possible,” said Papp, an environmental economist at the Massachusetts Institute of Technology.

A Broad Spectrum of Bans

Across the country, a hodgepodge of legislation exists to manage plastic bag waste, from strict bans (like the ones implemented in New Jersey, where single-use paper bags are also limited), to partial bans (like the ones in California, targeted at large retailers), to required fees (as in Oregon, where retailers must charge at least 5 cents for a thick, presumably reusable plastic bag). In addition to statewide legislation, hundreds of municipalities have their own plastic bag policies.

“During our data collection phase, I was initially surprised by the reach of plastic bag policies. We estimate that now one in every three Americans lives in an area with some bag policy,” said Papp.

Papp and Oremus were able to document the effectiveness of such policies, regardless of their reach. In places where some form of plastic bag legislation exists, data showed a 25%–47% decrease in the proportion of plastic bags recovered in coastline cleanups. Although all policies aimed at reducing plastic bag litter were effective, researchers found that those implemented at the state level correlated most strongly to reducing the amount of plastic bag waste found during beach cleanups.

“In some ways it’s like, well, of course, if you use fewer plastic bags, you’re going to find fewer plastic bags on the beach, but it’s good that [researchers] documented that in a quantitative way,” said Susanne Brander, an ecotoxicologist at Oregon State University who was not involved in the study. “We need those data in order to convince additional lawmakers and agencies to take this seriously and to think not just about plastic bags, but about other single-use items as well.”

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

Citation: Owen, R. (2025), Policy success: Fees and bans on plastic bags reduce beach trash, Eos, 106, https://doi.org/10.1029/2025EO250247. Published on 14 July 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.

Tropical cyclones hundreds of kilometers away from the Philippines are often more responsible for heavy rainfall than those that hit the country directly during the annual "Habagat" or southwest monsoon season from July to September, according to new research published in Atmospheric Research.