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    A ruinous hailstorm in Spain may have been supercharged by warming seas

    A torrent of giant hailstones in northeast Spain may have been fueled by climate change.

    On August 31, 2022, a brutal hailstorm struck the small Spanish city of La Bisbal d’Empordà. The storm unleashed balls of ice up to 12 centimeters wide, causing widespread damage to property and crops, injuring dozens of people and killing a 20-month-old toddler. Computer simulations now suggest that in a preindustrial climate, the storm could not have generated hailstones this big, researchers report in the March 28 Geophysical Research Letters.   More

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    Three reasons why the ocean’s record-breaking hot streak is devastating

    Earth’s largest ecosystem is broiling. Every day for the last 12 months, the average temperature of most of the sea’s surface has been the highest ever recorded on that calendar date, preliminary data from the National Oceanic and Atmospheric Administration show.

    “And we’re currently outpacing last year,” says Robert West, a NOAA meteorologist in Miami. “We’re continuing to set records, even now over last year’s records.”

    One of the primary reasons that global sea surface temperatures are so high is El Niño, a natural climate phenomenon that involves warm surface waters spreading across the tropical Pacific Ocean. El Niño is a recurring event, and this one emerged late last spring (SN: 7/13/23). More

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    ‘On the Move’ examines how climate change will alter where people live

    On the MoveAbrahm LustgartenFarrar, Straus and Giroux, $30

    Ellen Herdell’s nerves were nearing a breaking point. The fortysomething, lifelong Californian had noticed her home was increasingly threatened by wildfires. After relatives lost their house to a blaze and the constant threat traumatized her 9-year-old daughter, Herdell found herself up at 3 a.m. one night in 2020 searching Zillow for homes in Vermont.

    She’s not alone. Across the United States, people facing extreme fires, storms, floods and heat are looking for the escape hatch. In On the Move, Abrahm Lustgarten examines who these people are, where they live, where climate change may cause them to move and how this reshuffling will impact the country (SN: 5/12/20). More

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    Cold, dry snaps accompanied three plagues that struck the Roman Empire

    For those who enjoy pondering the Roman Empire’s rise and fall — you know who you are — consider the close link between ancient climate change and infectious disease outbreaks. 

    Periods of increasingly cooler temperatures and rainfall declines coincided with three pandemics that struck the Roman Empire, historian Kyle Harper and colleagues report January 26 in Science Advances. Reasons for strong associations between cold, dry phases and those disease outbreaks are poorly understood. But the findings, based on climate reconstructions from around 200 B.C. to A.D. 600, help “us see that climate stress probably contributed to the spread and severity of [disease] mortality,” says Harper, of the University of Oklahoma in Norman.   More

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    Numbats are built to hold heat, making climate change extra risky for the marsupials

    Numbats are curious creatures. The only marsupials that are active solely during the day, when they scratch at soil and rotting logs for termites, these squirrel-sized animals are built to hoard body heat. But that same energy-saving trait may put the already endangered animals at risk as the climate warms, a new study suggests.

    Already, even brief sun exposure on days over 23° Celsius (73° Fahrenheit) can severely limit the time the Australian marsupials can spend foraging, researchers report January 11 in the Journal of Experimental Biology. Numbats might rapidly overheat in the sun, even at relatively reasonable temperatures, the team finds. More

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    3 Antarctic glaciers show rapidly accelerated ice loss from ocean warming

    SAN FRANCISCO — Several Antarctic glaciers are undergoing dramatic acceleration and ice loss. Hektoria Glacier, the worst affected, has quadrupled its sliding speed and lost 25 kilometers of ice off its front in just 16 months, scientists say.

    The rapid retreat “is really unheard of,” says Mathieu Morlighem, a glaciologist at Dartmouth College who was not part of the team reporting these findings.

    The collapse was triggered by unusually warm ocean temperatures, which caused sea ice to retreat. This allowed a series of large waves to hit a section of coastline that is normally shielded from them. “What we’re seeing here is an indication of what could happen elsewhere” in Antarctica, says Naomi Ochwat, a glaciologist at the University of Colorado Boulder who presented the findings December 11 at the American Geophysical Union meeting.

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    Hektoria Glacier, Green Glacier, and Crane Glacier sit near the tip of the Antarctic Peninsula, which reaches up toward South America. The crescent moon–shaped bay, called the Larsen B Embayment, once seemed stable. As these glaciers oozed off the coastline, their ice used to merge into a floating slab around 200 meters thick. This slab, called the Larsen B Ice Shelf, was about the size of Rhode Island and filled the entire bay.

    Having existed for over 10,000 years, this ice shelf buttressed and stabilized the glaciers flowing into it. But during a warm summer in 2002, it suddenly fragmented into thousands of skinny icebergs (SN: 3/27/02).

    Hektoria, Green, and Crane glaciers — no longer contained by the ice shelf —  began to flow into the ocean several times faster than they had before, shedding billions of tons of ice over the next decade.

    Then starting in 2011, the hemorrhaging slowed down. The thin veneer of sea ice that forms over the bay each winter began to persist year round, preserved by a series of cold summers. This “landfast ice,” attached firmly to the coastline, grew five to 10 meters thick, stabilizing the glaciers. Their floating tongues gradually advanced back into the bay. But things changed abruptly in early 2022. On January 19 and 20, the landfast ice disintegrated into fragments, which drifted away.

    Satellite images taken just 10 days apart reveal the dramatic breakup of sea ice in Antarctica’s Larsen B Embayment. On January 16, 2022, sea ice filled the bay (left). By January 26 (right), the ice had fractured and was drifting away following a series of powerful waves that struck the bay several days earlier. Left: Joshua Stevens, MODIS/LANCE/EOSDIS/NASA, WORLDVIEW/GIBS/NASARight: Joshua Stevens, MODIS/LANCE/EOSDIS/NASA, WORLDVIEW/GIBS/NASA

    Using data from ocean buoys farther north, Ochwat and colleagues determined that a series of powerful waves, higher than 1.5 meters, had swept in from the northeast — cracking apart the landfast ice. Those waves were highly unusual for this area.

    The Southern Ocean, which encircles Antarctica, holds some of the world’s roughest waters. The Antarctic Peninsula extends up into this turbulent region, but its east side, where the Larsen B Embayment sits, rarely feels the waves. It is normally protected by several hundred kilometers of pack ice — floes of sea ice, pressed together by ocean currents — that dampen the waves, leaving the waters near Larsen as flat as a mirror.

    In 2022, water temperatures near the surface of the Southern Ocean rose several tenths of a degree Celsius higher than normal, causing pack ice to shrink and peel away from the peninsula. This exposed the area to waves, which then broke up the landfast sea ice.

    The glaciers accelerated as their floating tongues, no longer held in place, fragmented into bergs. Crane Glacier lost 11 kilometers of ice, nearly erasing its floating tongue; Green Glacier lost 18 kilometers, encompassing all of its floating ice.

    Hektoria lost all 15 kilometers of its floating ice — followed by another 10 kilometers of ice that is normally more stable, because it rests on the seafloor. That “is faster than any tidewater glacier retreat that we know of,” Ochwat says.

    The previous standout, Alaska’s Columbia Glacier, had lost 20 kilometers of ice in 30 years, records show. But Hektoria lost its 10 kilometers of nonfloating ice in just five months — including 2.5 kilometers that crumbled in a 3-day period.

    All of this suggests that people trying to predict sea level rise need to consider sea ice, Morlighem says. Up until now, “its role in [glacier] dynamics has been completely ignored.”

    Ochwat is waiting to see what will happen as the current Antarctic summer heats up between December and March. Hektoria and the other glaciers have been retreating only during summer months, when sea ice is absent; they pause during winter, when the surface of the bay freezes for a few months.

    If Antarctic sea ice continues to shrink, as it has since 2022, it could spell trouble, says study coauthor Ted Scambos, a glaciologist also at UC Boulder. “You’re going to have a longer section of coastline where wave action can act on the front of ice shelves and glaciers,” potentially accelerating glacial retreat. More

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    COP28 nations agreed to ‘transition’ from fossil fuels. That’s too slow, experts say

    Days of contentious wrangling in Dubai at the United Nations’ 28th annual climate summit ended December 13 with a historic agreement to “transition away” from fossil fuels and accelerate climate action over the next decade. The organization touted the agreement as a moment of global solidarity, marking “the beginning of the end” of the fossil fuel era.

    But the final agreement reached at COP28, signed by nearly 200 nations, did not include language that explicitly mandated phasing out fossil fuel energy, deeply frustrating many nations as well as climate scientists and activists.

    The agreement is considered the world’s first “global stocktake,” an inventory of climate actions and progress made since the 2015 Paris Agreement to limit global warming to “well below” 2 degrees Celsius above the preindustrial average (SN: 12/12/15).

    It acknowledges the conclusions of scientific research that greenhouse gas emissions will need to be cut by 43 percent by 2030 compared with 2019 levels, in order to limit global warming to 1.5 degrees Celsius by the end of the century. It then calls on nations to speed up climate actions before 2030 so as to reach global net zero by 2050 — in which greenhouse gases entering the atmosphere are balanced by their removal from the atmosphere. Among the actions called for are increasing global renewable energy generation, phasing down coal power and phasing out fossil fuel subsidies.

    But among many scientists gathered in San Francisco at the American Geophysical Union’s annual meeting to discuss climate change’s impacts to Earth’s atmosphere, polar regions, oceans and biosphere, the reaction to the language in the agreement was more frustrated than celebratory.

    “The beginning of the end? I wish it was the middle of the end,” says climate scientist Luke Parsons of the Nature Conservancy, who is based in Durham, N.C. “But you have to start somewhere, I guess.”

    It is a step forward, says Ted Scambos, a glaciologist at the University of Colorado Boulder. “Saying it out loud, that we are aiming to phase out fossil fuels, is huge.”

    It’s not a moment too soon: The globe is already experiencing many climate change–linked extreme weather events, including the hottest 12 months ever recorded (SN: 11/9/23). Still, Scambos says, “it’s a tribute to the science and the negotiators that we can take this step now, before the disastrous global impacts truly get underway.” But, he added, “I fear that the pace [of future climate action] will … still be driven by impacts arriving at our collective doors.”

    Other researchers had a grimmer take.

    “It was weak sauce,” says climate scientist Michael Mann of the University of Pennsylvania. “What we really need is a commitment to phase out fossil fuels, on a very specific timeline: We’re going to reduce carbon emissions by 50 percent this decade, bring them down to zero mid-century. Instead, they agreed to transition away from fossil fuels — the analogy that I use is, you’re diagnosed with diabetes, and you tell your doctor you’re going to transition away from doughnuts. That’s not going to cut it. It didn’t meet the moment.”

    Eric Rignot, a glaciologist at the University of California, Irvine, called the agreement “deeply disappointing and misleading,” noting that it didn’t include any language specifically calling for phasing out fossil fuels. Furthermore, he says, “COP28 keeps entertaining the idea that 1.5 degrees Celsius may be achievable, but everyone is offtrack to meet that goal. [And] for ice sheets and glaciers, even 1.5 degrees is not sustainable.”  There already are fears, for instance, that the melting of Greenland’s ice sheet can’t be stopped (SN: 8/9/21).

    Even if the world stays close to that average temperature, “the ice sheets are going to be retreating,” says Rob DeConto, a glaciologist at the University of Massachusetts at Amherst. “But you start getting out toward the end of the century, and all hell is going to break loose if we go much above 1.5. You’re talking about actually exceeding the limits of adaptation around so much of our coastlines.”  

    On December 12, the eighth anniversary of the signing of the Paris Agreement, the European Union’s Copernicus Climate Change Service noted that the world has, in effect, “lost” 19 years by delaying action to reduce fossil fuel emissions. Back in 2015, climate projections suggested that Earth’s average temperature would reach the 1.5 degrees C threshold by the year 2045 — then 30 years away. Now, projections show that the planet may reach that benchmark by 2034, just 11 years in the future.

    “We’ve got a shrinking window of opportunity,” Mann says. “And that window of opportunity will close if we don’t make dramatic and immediate reductions to our carbon emissions.” More

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    COP28 is making headlines. Here’s why the focus on methane matters

    This year’s United Nations’ annual climate summit, dubbed COP28, is making a lot of headlines — not something I would have found myself writing a few years ago.

    One reason for COP’s higher profile is a growing sense of urgency to take stronger action to reduce humans’ fossil fuel emissions and mitigate the looming climate crisis. The world is nowhere near on track to meet the goals of the 2015 Paris Agreement — that is, reducing greenhouse gas emissions sufficiently to limit global warming to “well below” 2 degrees Celsius of preindustrial averages by the year 2100 (SN: 12/12/15). Meanwhile, 2023 has been the hottest year on record, people have been suffering through a barrage of extreme weather events, including heat waves, droughts and floods, and 2024 is likely to break more temperature records (SN: 12/6/23; SN: 7/19/23).

    The headlines emerging from COP28 have been a mix of pleasing, frustrating and bewildering. For example: It’s good news that 198 nations have ratified the Loss and Damage Fund, a formal acknowledgment by wealthy, high-polluting nations that they should help mitigate the rising costs of climate change faced by developing nations. But it’s frustrating that the pledges by the wealthy nations so far amount to just about $725 million, less than 0.2 percent of the annual climate change–linked losses faced by developing nations.

    For me, one of the biggest questions related to those headlines pertains to methane. It feels unclear whether, on balance, there’s more good or bad news when it comes to emissions of that second most important human-caused greenhouse gas.

    Methane is a powerhouse climate-warming gas, with about 80 times the atmosphere-warming potential of carbon dioxide. However, methane has a saving grace: It mercifully lingers for only about a decade in the atmosphere (SN: 4/22/20). Carbon dioxide can stick around for up to 1,000 years. Cutting methane emissions can mean its atmospheric concentration drops relatively rapidly.

    The Global Methane Pledge, launched two years ago at COP26, may be gaining some momentum, but it still lacks the sign-on of key big-emitting nations. Then there’s the December 1 announcement by 49 oil and gas companies that they would reduce methane leaks from their infrastructure to “near zero” by 2030, which seems like a good thing on the face of it but has also been called greenwashing (SN: 11/24/21).

    And all of this policy wrangling is happening against a bizarre backdrop: a startling, puzzling, worrisome sharp increase in methane emissions over the last decade — not from humans, but from natural sources, particularly wetlands.

    To help me sift through the headlines and better understand all the news that’s seeping out, I talked with Euan Nisbet, a geochemist at Royal Holloway, University of London in Egham.

    Methane “is rising very fast,” Nisbet says. “So fast it looks like the Paris Agreement is going to fail.”

    Countries are promising to cut methane emissions

    While the rise in natural methane emissions is worrisome, about 60 percent of current methane emissions into the atmosphere still comes from human activities. Methane doesn’t just seep out of leaky oil and gas pipelines or get pumped into the air during coal combustion. Agriculture, including ruminant animals, are a big source (SN: 5/5/22). Landfills are another (SN: 11/14/19).

    That’s where the Global Methane Pledge comes in, promising a 30 percent cut in humans’ emissions by 2030. The pledge was spearheaded in 2021 by the United States and the European Union, and so far, 150 nations have signed on. Most recently, Turkmenistan, which has sizable methane emissions, joined. So there’s hope: If everyone were to follow suit, it really is possible to cut global methane emissions deeply, bringing us much closer to meeting the Paris Agreement’s goals, Nisbet argues in a Dec. 8 editorial in Science.

    Still, many of the world’s biggest methane emitters, including China, India, Russia, Iran and South Africa, have not signed on to the pledge. China’s methane comes in large part from its coal combustion; India’s, from coal as well as waste heaps and biomass fires. And China alone currently releases an estimated 65 million metric tons of methane per year, more than double that of the United States or India, the next two biggest emitters.

    With only seven years left before the 2030 deadline, meeting the global pledge’s methane reduction goals would be steep — but, Nisbet says, not impossible.

    There’s precedent for successfully making such steep cuts to methane in such a short time, he adds. During the 2000s, “there was a seven-year period where [the U.K. government] brought methane emissions down by 30 percent,” in large part by reducing emissions from landfills and gas leaks.

    China has just released its own Methane Emissions Control Action Plan in November, alongside a joint commitment between China and the United States to take action on methane. That news sounds potentially promising, if not wholly reassuring, as the plan does not include a lot of concrete numbers, Nisbet says.

    So, what about the oil and gas industry’s recent promise to address its leaky infrastructure? Such a promise also sounds positive on the face of it — leaky infrastructure is definitely the low-hanging fruit when it comes to reducing humans’ methane emissions to the atmosphere (SN: 2/3/22).

    On the other hand, hundreds of scientific and environmental organizations have signed an open letter in response. The letter suggests that the oil and gas industry’ promise is just greenwashing, “a smokescreen to hide the reality that we need to phase out oil, gas and coal,” the letter states. Furthermore, many oil and gas companies may routinely abandon old, still-leaking wells — effectively eliminating those leaks from their company’s emissions roster without actually stopping them.

    That said, addressing the leaks does have to be done, Nisbet says. “I’d love to shut down the coal industry quickly, but I’m aware of the enormous social problems that brings. It’s a very difficult thing to nuance. You can’t go cold turkey. We’ve got to wind it down in an intelligent and collaborative way. The best thing to do is to stop the crazy leaks and venting.”

    Natural methane emission has been surging

    Plugging the leaks as soon as possible has taken on an increasing urgency, Nisbet says, because of a stark rise in natural methane being emitted to the atmosphere. Why this rise is happening isn’t clear, but it seems to be some sort of climate change–related feedback, perhaps linked to changes in both temperature and precipitation.

    That natural methane emissions bump was also not something that the architects of the Paris Agreement saw coming. Most of that rise has happened since the agreement was signed. From 1999 to 2006, atmospheric methane had spent several years in near-equilibrium — elevated due to human activities, but relatively stable. Then, in 2007, atmospheric methane concentrations began to increase. In 2013, there was a particularly sharp rise, and then again in 2020.

    Much of that increase seems to have come from tropical wetlands. Over the past decade, researchers have tracked shifts in methane sources by measuring carbon-12 and carbon-13 in the gas. The ratio of those two forms of carbon in the methane varies significantly depending on the source of the gas. Fossil fuel-derived methane tends to have higher concentrations of carbon-13 relative to carbon-12; methane from wetlands or agriculture tends to be more enriched in carbon-12.

    The recent spikes in natural methane are eerily reminiscent of ice core records of “glacial termination” events, times in Earth’s deep past when the world abruptly shifted from a glacial period to a period of rapid warming, Nisbet and others reported in June in Global Biogeochemical Cycles. Such glacial termination events are large-scale reorganizations of the ocean-atmosphere system, involving dramatic changes to the circulation of the global ocean, as well as to large climate patterns like the Indian Ocean Dipole (SN: 1/9/20).

    “Is this comparable to the start of a termination event? It looks horribly like that,” Nisbet says. But “it may not be. It might be totally innocent.”

    Right now, scientists are racing to understand what’s happening with the natural methane bump, and how exactly the increased emissions might be linked to climate change. But as we search for those answers, there is something that humans can and must do in the meantime, he says: Cut human emissions of the gas as much as possible, as fast as possible. “It’s very simple. When you’re in a hole, stop digging.” More