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    As the Arctic tundra warms, soil microbes likely will ramp up CO2 production

    Climate change is warming the Arctic tundra about four times faster than the rest of the planet. Now, a study suggests that rising temperatures will spur underground microbes there to produce more carbon dioxide — potentially creating a feedback loop that worsens climate change.The tundra is “a sleepy biome,” says Sybryn Maes, an environmental scientist at Umeå University in Sweden. This ecosystem is populated by small shrubs, grasses and lichen growing in cold soils rich with stored organic carbon. Scientists have long suspected that warming will wake this sleeping giant, prompting soil microbes to release more of the greenhouse gas CO2 (SN: 8/11/22). But it’s been difficult to demonstrate in field studies.

    Maes’ team included about 70 scientists performing measurements in 28 tundra regions across the planet’s Arctic and alpine zones. During the summer growing season, the researchers placed clear, open-topped plastic chambers, each about a meter in diameter, over patches of tundra. These chambers let in light and precipitation but blocked the wind, warming the air inside by an average of 1.4 degrees Celsius. The researchers monitored how much CO2 microbes in the soil released into the air, a process called respiration, and compared that data with measurements from nearby exposed patches. More

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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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    Ximena Velez-Liendo is saving Andean bears with honey

    In 1998, at the age of 22, conservation biologist Ximena Velez-Liendo came face-to-face with South America’s largest carnivore on her first day of field research in Bolivia. Her life changed forever when she turned around to see “this beautiful, amazing bear coming out of the forest,” Velez-Liendo says. “It was like love at first sight.” She thought in that moment: “If I can do anything for you, I’ll do it.”

    Also known as spectacled bears, Andean bears are easily recognized by the ring of pale fur that often encircles one or both eyes. Bolivia is home to about 3,000 adult bears, or roughly one-third of the world’s total Andean bears, whose range arcs through five countries along the western edge of South America. Listed as vulnerable by the International Union for Conservation of Nature, or IUCN, the species (Tremarctos ornatus) suffers mainly from habitat loss and conflicts with humans, who sometimes kill the bears in retaliation when bears raid crops or hunt livestock. 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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    Polar forests may have just solved a solar storm mystery

    The strongest solar flare in recorded history burst into Earth’s atmosphere in 1859, bathing both hemispheres in brilliantly colorful aurorae as it wreaked worldwide havoc on telegraph systems. The celestial chaos was broadly witnessed, but lingering physical evidence of that storm, dubbed the Carrington event, has proven stubbornly elusive — until now, researchers report in the March 16 Geophysical Research Letters.

    Ecologist Joonas Uusitalo of the University of Helsinki and his colleagues have identified the first known traces of the Carrington event: atoms of carbon-14 preserved in tree rings in Finland’s far north. Scientists previously hadn’t detected tree ring evidence of this event, although other trees have recorded more powerful solar flares that occurred before modern recordkeeping began, such as in 774 and 993. More

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    Heat waves cause more illness and death in U.S. cities with fewer trees

    In the United States, urban neighborhoods with primarily white residents tend to have more trees than neighborhoods whose residents are predominantly people of color. A new analysis has now linked this inequity to a disparity in heat-related illness and death, researchers report April 8 in npj Urban Sustainability. 

    Neighborhoods with predominantly people of color have 11 percent less tree cover on average than majority white neighborhoods, and air temperatures are about 0.2 degrees Celsius higher during summer, urban ecologist Rob McDonald of The Nature Conservancy and colleagues found. Trees already prevent 442 excess deaths and about 85,000 doctor visits annually in these neighborhoods. In majority white neighborhoods, trees save around 200 more lives and prevent 30,000 more doctor visits. 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