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    Earth’s landmasses lost trillions of tons of water this century

    Earth’s landmasses are holding onto a lot less water than they used to — and this loss is not just due to melting ice sheets. Terrestrial water storage, which includes water in underground aquifers, lakes, rivers and the tiny pore spaces within soil, declined by trillions of metric tons in the early 21st century, researchers report in the March 28 Science.

    This sharp decrease in freshwater stores is driven by rising temperatures on land and in the oceans, which in turn are linked to an increased global incidence of drought. And given the projected warming of the planet, this trend isn’t likely to change any time soon, say geophysicist Ki-Weon Seo of Seoul National University and colleagues. More

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    Hidden Antarctic lakes could supercharge sea level rise

    Beneath the great, white expanse of the Antarctic Ice Sheet, a mysterious realm of streams and lakes lies out of sight. Much about this hidden water world remains poorly understood. But a new study suggests that if scientists continue to overlook it, they might greatly underestimate global sea level rise.

    Factoring this subglacial water into computer simulations could boost projections of sea level rise over the next two centuries by about two meters, researchers report April 7 in Nature Communications. For context, scientists estimate that climate warming has raised sea levels by about 0.2 meters over the last century. More

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    Fires in the Amazon forest may melt sea ice in Antarctica

    Soot from forest fires in the Amazon might play a role in the melting of faraway ice in Antarctica.

    For decades, scientists have known that black carbon from burning fossil fuels or forests accelerates ice melt in different parts of the world. According to remote sensing researcher Sudip Chakraborty, the slash-and-burn practices encouraged by Brazil’s former president Jair Bolsonaro, who held office from 2019 to 2023, inspired his team to investigate whether black carbon from the Amazon affected ice melt in Antarctica. More

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    Spotting climate misinformation with AI requires expertly trained models

    Conversational AI chatbots are making climate misinformation sound more credible, making it harder to distinguish falsehoods from real science. In response, climate experts are using some of the same tools to detect fake information online.

    But when it comes to classifying false or misleading climate claims, general-purpose large language models, or LLMs­ — such as Meta’s Llama and OpenAI’s GPT-4­ — lag behind models specifically trained on expert-curated climate data, scientists reported in March at the AAAI Conference on Artificial Intelligence in Philadelphia. Climate groups wishing to use commonly available LLMs in chatbots and content moderation tools to check climate misinformation need to carefully consider the models they use and bring in relevant experts to guide the training process, the findings show. More

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    A lush, green Arabian Desert may have once linked Africa and Asia

    The Arabian Desert, today the largest expanse of windswept sand dunes on Earth, experienced recurring periods of humidity millions of years ago, researchers report April 9 in Nature. The study may explain how mammals at that time survived the trek across what is now a vast and barren landscape.

    The findings come from mineral formations deep inside caves beneath the Arabian Peninsula. These speleothems — stalagmites and stalactites, formed by dripping rainwater — provide evidence that the region underwent repeated humid periods stretching back nearly 8 million years. The scientists used uranium dating to precisely determine the ages of speleothem samples, offering one of the oldest climate records for the region. More

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    Solar geoengineering moves into the spotlight as climate concerns grow

    Earth’s average temperature is continuing to tick inexorably upward as the world’s nations stall at reducing their atmosphere-warming emissions. In the face of that grim future, strategies to try to turn down the planet’s thermostat are gaining traction. One strategy in particular — solar geoengineering, which aims to cool the planet by reflecting solar radiation back into space — may be having a moment in the sun.

    Depending on whom you ask, it’s potentially highly dangerous, highly promising or highly uncertain. There aren’t any real guidelines. But, with the future of emissions restrictions also highly uncertain, some researchers say solar geoengineering needs to be on the table. More

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    The ozone layer shields life on Earth. We’ll soon lose a key way to monitor its health

    Humankind will soon lose a great deal of vigilance over the ozone layer, which shields life on Earth from harmful solar radiation.

    The impending loss of NASA’s Aura and the Canadian Space Agency’s SCISAT satellites threatens scientists’ ability to closely monitor compounds that destroy ozone and alter stratospheric circulation. With no planned missions to replace either satellite, a data desert in the stratosphere appears imminent, researchers warn in the March Bulletin of the American Meteorological Society. More

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    Splitting seawater offers a path to sustainable cement production

    A new cement-making process could shift production from being a carbon source to a carbon sink, creating a carbon-negative version of the building material, researchers report March 18 in Advanced Sustainable Systems. This process might also be adaptable to producing a variety of carbon-stashing products such as paint, plaster and concrete.

    Cement production is a huge contributor to global carbon dioxide emissions, responsible for about 8 percent of total CO2 emissions, making it the fourth-largest emitter in the world. Much of that carbon comes from mining for the raw materials for concrete in mountains, riverbeds and the ocean floor. More