It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Tuesday, January 21, 2025
After millennia as carbon dioxide sink, more than one-third of Arctic-boreal region is now a source
Credit: Greg Fiske / Woodwell Climate Research Center
After millennia as a carbon deep-freezer for the planet, regional hotspots and increasingly frequent wildfires in the northern latitudes have nearly canceled out that critical storage capacity in the permafrost region, according to a new study published in Nature Climate Change.
An international team led by Woodwell Climate Research Center found that a third (34 percent) of the Arctic-boreal zone (ABZ)—the treeless tundra, boreal forests, and wetlands that make up Earth’s northern latitudes—is now a source of carbon to the atmosphere. That balance sheet is made up of carbon dioxide (CO₂) uptake from plant photosynthesis and CO₂ released to the atmosphere through microbial and plant respiration.
When emissions from fire were added, the percentage grew to 40 percent.
The findings represent the most current and comprehensive assessment of carbon fluxes in the ABZ to date. Drawing on a library of CO₂ data four times as large as earlier upscaling efforts gathered from 200 study sites from 1990-2020, the analysis captures both year-round dynamics and important recent shifts in climate and northern fire regimes that have altered the carbon balance in the north.
“We wanted to develop the most current and comprehensive picture of carbon in the north, and to do that, we knew we needed to account for fire’s growing carbon footprint in this region,” said Dr. Anna Virkkala, a research scientist at the Permafrost Pathways initiative at Woodwell Climate and lead author of the study. “While we found many northern ecosystems are still acting as carbon dioxide sinks, source regions and fires are now canceling out much of that net uptake and reversing long-standing trends.”
The study is a robust record of how land in the northern latitudes is breathing—measuring the gasses it releases and pulls down from the atmosphere. Data are gathered at carbon flux monitoring towers and chambers, which track gas exchange between the land and the atmosphere.
These data are stored and analyzed in a comprehensive and growing library dubbed “ABC Flux,” which Virkkala helms. ‘Upscaling’ refers to the process by which these individual site-level readings are knitted together with climate, soil, and vegetation records to produce living maps of Earth’s otherwise invisible exhalations and inhalations.
By tracking monthly records over three decades, the Nature Climate Change study helps illustrate the “why” behind the trends: for instance, carbon uptake in the summers has increased over the 30 years, but more carbon emissions are being released from the tundra during the non-growing season months.
Another advantage this study offers is relatively high resolution—1km x 1km for 2001-2020—allowing the researchers to map the “where” shaping these trendlines.
“The high resolution of these data means that we can now see how variable the Arctic is when it comes to carbon,” said Dr. Sue Natali, a co-author on the study and lead of Permafrost Pathways at Woodwell Climate. “That variability isn’t surprising because the Arctic isn’t one single place—it’s a massive area with diverse ecosystems and climatic conditions. And now we have the capability to track and map carbon processes at a spatial resolution that can reveal what’s happening on the ground.”
“We are seeing that longer growing seasons and more microbial activity in winter are gradually shifting carbon trajectories,” said Dr. Marguerite Mauritz, assistant professor at the University of Texas-El Paso and co-author of the study. “Highly collaborative efforts like this are critical for understanding how shifting seasonal dynamics and disturbance patterns can have regional and even global impacts.”
The latest findings add to a growing ensemble of recent studies that show how carbon budgets in the North are changing after the region’s historical role as a sink. While this study focused on CO₂ fluxes on land, other recent results that count CO₂ and methane (CH₄) emissions from lakes, rivers, and wetlands also found the permafrost region to be a carbon source.
But the recent cache of upscaling results tells similar stories: namely, that trendlines in the northern latitudes are beginning to turn, and a warmer, greener Arctic does not reliably translate to more carbon storage there—in part because warmer has meant emissions from permafrost thaw and greener, more carbon to combust.
For example, the Nature Climate Change study found that while 49 percent of the ABZ region experienced “greening”—in which longer growing seasons and more vegetation means that more carbon can be photosynthesized and stored—only 12 percent of those greening pixels on the map showed an annual increasing net uptake of CO₂.
“Carbon cycling in the permafrost region is really starting to change,” Virkkala said. “Our study may act as a warning sign of bigger changes ahead, and offers a map of places we’ll need to better monitor in the coming decades.”
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This work was funded by the Gordon and Betty Moore Foundation and funding catalyzed through the TED Audacious Project for Permafrost Pathways: Connecting Science, People, and Policy for Arctic Justice and Global Climate.
Map of Arctic-boreal zone study area depicting boreal forests, tundra, and permafrost region.
Average terrestrial CO2 balance from 2001-2020 based on a synthesis of field measurements and machine learning models.
Credit
Greg Fiske / Woodwell Climate Research Center
Terrestrial CO2 balance in the Arctic-boreal zone, 2001-2020 (VIDEO)
X BlueskyMessageWhatsEmailA new study provides compelling new evidence that a colossal ‘megaflood’ refilled the Mediterranean Sea, ending a period during which the Med was a vast expanse of salt flats.
The study suggests the Zanclean Megaflood ended the Messinian Salinity Crisis, which lasted between 5.97 and 5.33 million years ago.
An international team of scientists, including the University of Southampton, have identified a series of geological features around South East Sicily that point to a massive flood taking place across the region.
“The Zanclean megaflood was an awe-inspiring natural phenomenon, with discharge rates and flow velocities dwarfing any other known floods in Earth’s history,” said Dr. Aaron Micallef, lead author of the study and researcher at the Monterey Bay Aquarium Research Institute in California. “Our research provides the most compelling evidence yet of this extraordinary event.”
During the Messinian Salinity Crisis, the Mediterranean Sea became isolated from the Atlantic Ocean and evaporated, leading to vast salt deposits which reshaped the region’s landscape.
For years, scientists had thought that this dry period ended gradually, with the Mediterranean refilling over a period of 10,000 years. But this idea was challenged by the discovery of an erosion channel stretching from the Gulf of Cadiz to the Alboran Sea in 2009. The finding pointed to a single, massive flooding event, lasting between two and 16 years, which became known as the Zanclean megaflood.
Estimates suggest the megaflood had a discharge from 68 to 100 Sverdrups (Sv), with one Sv equal to one million cubic metres per second.
The researchers investigated over 300 asymmetric, streamlined ridges in a corridor across the Sicily Sill - a submerged land bridge that once separated the western and eastern Mediterranean basins.
"The morphology of these ridges is compatible with erosion by large-scale, turbulent water flow with a predominantly north easterly direction,” says Professor Paul Carling, an Emeritus professor in the School of Geography and Environmental Science at the University of Southampton and a coauthor of the study.
“They reveal the immense power of the Zanclean Megaflood and how it reshaped the landscape, leaving lasting imprints on the geological record.”
By sampling the ridges, the team found they were topped with a layer of rocky debris containing material eroded from the ridge flanks and the surrounding region, indicating it was deposited there quickly and with immense force.
This layer is right at the boundary between the Messinian and Zanclean periods when the megaflood is believed to have occurred.
Using seismic reflection data - a kind of geological ultrasound allowing scientists to see layers of rock and sediment beneath the surface, the researchers discovered a ‘W-shaped channel’ on the continental shelf east of the Sicily Sill.
This channel, carved into the seabed, connects the ridges to the Noto Canyon - a deep underwater valley located in the eastern Mediterranean.
The shape and location of the channel suggest that it acted like a massive funnel. When the megaflood waters poured over the Sicily Sill, this channel likely carried the water toward the Noto Canyon and into the eastern Mediterranean.
The team developed computer models of the megaflood to simulate how the water might have behaved. The model suggests that the flood would have changed direction and grown in intensity as time went on, reaching speeds of up to 32 meters per second (72 miles per hour), carving deeper channels, eroding more material, and transporting it over longer distances.
“These findings not only shed light on a critical moment in Earth’s geological history but also demonstrate the persistence of landforms over five million years,” Dr Micallef added. “It opens the door to further research along the Mediterranean margins.”
The research was supported by the National Geographic Society, Deutsche Forschungsgemeinschaft, and the David and Lucile Packard Foundation.
The University of Southampton drives original thinking, turns knowledge into action and impact, and creates solutions to the world’s challenges. We are among the top 100 institutions globally (QS World University Rankings 2025). Our academics are leaders in their fields, forging links with high-profile international businesses and organisations, and inspiring a 22,000-strong community of exceptional students, from over 135 countries worldwide. Through our high-quality education, the University helps students on a journey of discovery to realise their potential and join our global network of over 200,000 alumni. www.southampton.ac.uk
EUGENE, Ore. — Jan. 21, 2025 — Increased exposure to glyphosate, one of the most widely used herbicides in the United States and much of the world, harms infant health in U.S. agricultural counties, according to a new study by two University of Oregon economists.
They note that because pre-term births, on average, cost an estimated $82,000 in additional medical, educational and other expenses compared to a full-term birth, the national economic impact of the infant health effects translates to between $750 million and $1.1 billion in annual expenses. It does not include other potential health costs.
Reynier is a doctoral candidate in economics whose work is supported by a research fellowship with the U.S. Environmental Protection Agency. Rubin is an environmental economist and assistant professor in the Department of Economics.
The EPA first approved glyphosate for use as an herbicide in the United States in 1974. Federal law requires such decisions to be reviewed every 15 years. In 2020, the agency determined that, if used according to label directions, glyphosate poses no risks to human health. The EPA also found that the herbicide is unlikely to cause cancer in humans.
In 2022, those findings were challenged in court and voided by the U.S. Court of Appeals for the 9th Circuit. They are still under review.
Glyphosate kills plants that are not genetically modified to withstand the herbicide. Farmers can use it to kill weeds in fields planted with crops such as genetically modified corn, soybeans and cotton, which were first permitted for agricultural use in 1996. Since the introduction of genetically modified crops, annual glyphosate use in the U.S. has increased about 750 percent, according to a report from the U.S. Geological Survey.
Reynier and Rubin jointly planned their study to establish a more rigorous basis for understanding the effects of glyphosate on human health.
“We had heard some pretty broad claims about the effects of pesticides on health that seemed to be based more on correlations than on causal effects,” Reynier said. “We know people are concerned, and we wanted to make sure we were looking at this rigorously.”
In their study, the researchers evaluated human health effects using three types of existing data for rural U.S. counties: genetically modified crop suitability, historical pesticide applications and birth records.
From the United Nations’ Food and Agricultural Organization, they gathered data on crop suitability as determined by soils and climate. They used that data to rate agricultural counties on their suitability for raising genetically modified corn, cotton and soybeans. Counties highly suited to such crops, largely places where non-genetically modified versions of these crops were already grown, saw significantly larger increases in glyphosate use after 1996.
Data on births came from the U.S. Department of Health and Human Services. Rubin and Reynier selected a set of more than 9 million birth records in rural counties from 1990 to 2013. All the data were anonymous. Identifying information, such as the precise locations of crop fields and birth parents’ homes, was not included.
“By using the mother’s county, we matched the infant to the glyphosate exposure estimate. And then we asked how much birthweight changed in the higher-suitability counties versus lower-suitability counties,” said Rubin.
Prior to 1996, the data show that trends in two birth outcomes, birthweight and gestation, remained quite similar in counties less and more suitable for genetically modified crops. However, after 1996 infant health deteriorated sharply in counties more suitable for those crops relative to less suitable counties. Rubin and Reynier attribute that relative deterioration to the change in glyphosate use caused by the introduction of genetically modified seeds.
The researchers controlled for any unobserved factors that might have affected health before and after birth from year to year or across counties.
The results imply that at average levels of glyphosate exposure, average gestation was reduced by one day and average birthweight was reduced by 23-32 grams, about 1 ounce.
However, they also found that the changes did not affect all births equally. By considering how shorter gestation and reduced birthweight were spread out across all births, they found that glyphosate’s effects were largest among babies with the lowest expected birthweight.
“What this means is that, for whatever reason, if an infant is expected to be at the very low birthweight end of the scale, then glyphosate exposure could affect you more,” Rubin said. “It’s like being sick and then getting hit with another illness. You’re more vulnerable.”
Combined with other recent work, the findings challenge the prevailing regulatory position that genetically engineered crops and their associated agricultural practices are safe — and even beneficial — for health, Rubin and Reynier wrote.
“I think something has to change,” Rubin said. “Regulators could admit that glyphosate exposure presents some concerns for human health. There’s mounting evidence that it could be detrimental.”
In addition, he said, there could be greater monitoring of glyphosate use and exposure as well as human health.
“We’re still not tracking it in water. We’re not tracking it when it’s applied,” he said. “It does seem like, even if we’re not ready to regulate it in a serious way, we could monitor it.”
— By Nick Houtman, for University Communications
This project was supported in part by an appointment to the Research Participation Program at the Water Economics Center, U.S. Environmental Protection Agency, administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the U.S. Department of Energy and EPA.
About the University of Oregon College of Arts and Sciences The University of Oregon College of Arts and Sciences supports the UO’s mission and shapes its identity as a comprehensive research university. With disciplines in humanities and social and natural sciences, the College of Arts and Sciences serves approximately two-thirds of all UO students. The College of Arts and Sciences faculty includes some of the world’s most accomplished researchers, and the more than $75 million in sponsored research activity of the faculty underpins the UO’s status as a Carnegie Research I institution and its membership in the Association of American Universities.
Journal
Proceedings of the National Academy of Sciences
Article Title
Glyphosate exposure and GM seed rollout unequally reduced perinatal health
Alcohol sales spike after a public mass shooting, according to a study. The increase in alcohol consumption could further increase firearm-related violence in affected communities.
Nicholas R. Buttrick and colleagues analyzed data from 35,000 alcohol retailers, covering more than half of all American grocery and drug-store purchases from 2006–2019, and found that a public mass shooting in a community predicts a 3.5%–5.5% increase in weekly alcohol sales for at least two years. The effect is found for public shootings; mass shootings in private homes did not affect alcohol sales. The authors attribute the increase in alcohol consumption to the trauma or dislocation felt by members of the public in communities where shootings occurred. According to the authors, the result may underestimate the effects of shooting-related trauma on alcohol sales because the data do not include bodegas, independent liquor stores and wineshops, bars, or restaurants. Ironically, high levels of alcohol use are associated with firearm violence, which could in turn produce yet more trauma, in what the authors term “negative spirals of violence.” The authors call for whole-community approaches to addressing the trauma of mass shootings.
Journal
PNAS Nexus
Article Title
Mass shootings durably increase the sale of alcohol in American communities
Article Publication Date
21-Jan-2025
Surveys reveal zone of possible agreement for Israeli–Palestinian peace agreement
A 2022 survey of Palestinians and Israelis identifies a set of peace deals that would be preferable to the status quo for majorities on both sides of the conflict.
Between March and May of 2022, Elisa Cavatorta and colleagues asked nationally representative samples of 1,197 Palestinians and 679 Israelis to rank hypothetical peace agreements. Each agreement consisted of eight components, varied in a controlled manner. This methodology enabled the calculation of the strength of preference for each component and the overall acceptability of 256 potential agreements compared to the then-status quo. The study identified 55 peace agreements as mutually preferable to the status quo, forming a Zone of Possible Agreements (ZOPA). As expected, Palestinians and Israelis demonstrated divergent priorities, reflected in both different preferences for the status quo, different rankings and often, though not always, opposing preferences for the eight components. The status quo was ranked last among the options for 17% of Israelis and 41% of Palestinians. Israelis prioritized recognition of Israel as a nation-state for the Jewish people, while Palestinians emphasized halting settlement expansions. Mutually supported agreements did not necessarily include the highest priorities for both parties, but highlighted areas of potential agreement. These agreements focused on practical improvements to daily life, including the recognition of Israel, freedom of movement, mutual access to holy sites, and mutual prisoner release. Women and older respondents displayed a greater willingness to compromise than men and younger respondents. The study provides a snapshot of preferences as of 2022. Additional findings suggest that exposure to violence reduces willingness to compromise, particularly among Israelis. According to the authors, these results emphasize the critical need for an immediate cessation of hostilities and release of all hostages to facilitate progress.
Journal
PNAS Nexus
Article Title
Revealing the zone of possible agreement between parties in conflict: An application to Israeli-Palestinian peace agreements
