Ancient hunters who stalked the world’s last woolly mammoths likely helped warm the Earth’s far northern latitudes thousands of years before humans began burning fossil fuels, according to a study of prehistoric climate change.
The demise of the leaf-chomping woolly mammoths contributed to a proliferation of dwarf birch trees in and around the Arctic, darkening a largely barren, reflective landscape and accelerating a rise in temperatures across the polar north, researchers at the Carnegie Institution for Science concluded.
The northward march of vegetation affected the climate because of the “albedo effect,” in which replacement of white snow and ice with darker land surfaces absorbs more sunlight and creates a self-repeating warming cycle, the study found.
The end of the last Ice Age, marked by a rise in temperatures worldwide and the dramatic retreat of glaciers that once covered much of the Northern Hemisphere, was already under way when the extinction of woolly mammoths began.
But the latest findings, scheduled to be published in the Geophysical Research Letters journal, suggest human activity played a role in altering Earth’s climate long before mankind began burning coal and oil for energy, though the effects of prehistoric hunting were minute by comparison.
If mammoth hunters helped hasten Arctic warming, that would potentially be the first such human impact on climate, preceding that caused by ancient farmers, Chris Field, director of the Carnegie Institution’s Department of Global Ecology and a coauthor of the study, said on Tuesday.
With the advent of agriculture about 7,000 years ago at more southern latitudes, humans are believed to have modified the climate through deforestation and cultivation of new plants, he said.
The research attributes about a fourth of the Arctic’s vegetation-driven warming to the decline of the woolly mammoth.
If human hunters helped kill off the large mammals, they bear some responsibility for warming the climate, the scientists said.
“We’re not saying this was a big effect,” Field said. “The point of the paper isn’t that this is a big effect. But it’s a human effect.”
On the Chinese microblogging platform Sina Weibo, enthusiastic slackers share their tips: Fill up a thermos with whiskey, do planks or stretches in the work pantry at regular intervals, drink liters of water to prompt lots of trips to the toilet on work time, and, once there, spend time on social media or playing games on your phone. “Not working hard is everyone’s basic right,” one commenter wrote. “With or without legal protection, everyone has the right to not work hard.” Young Chinese people are pushing back against an engrained culture of overwork, and embracing a philosophy of laziness known as “touching
‘STUNNED’: With help from an official at the US Department of Justice, Donald Trump reportedly planned to oust the acting attorney general in a bid to overturn the election Former US president Donald Trump was at his Florida resort on Saturday, beginning post-presidency life while US President Joe Biden settled into the White House, but in Washington and beyond, the chaos of the 45th president’s final days in office continued to throw out damaging aftershocks. In yet another earth-shaking report, the New York Times said that Trump plotted with an official at the US Department of Justice to fire the acting attorney general, then force Georgia Republicans to overturn his defeat in that state. Meanwhile, former acting US secretary of defense Christopher Miller made an extraordinary admission, telling Vanity Fair that
The Palauan president-elect has vowed to stand up to Chinese “bullying” in the Pacific, saying that the archipelago nation is set to stand by its alliances with “true friends,” Taiwan and the US. Surangel Whipps Jr, 52, a supermarket owner and two-time senator from a prominent Palauan family, is to be sworn in as the new president tomorrow, succeeding his brother-in-law, Tommy Remengesau Jr. In a forthright interview, Whipps said that the US had demonstrated over the years that it was a reliable friend of Palau, most recently shown by its delivery of 6,000 doses of the Moderna COVID-19 vaccine. “It’s important for
Boeing set a target of designing and certifying its jetliners to fly on 100 percent sustainable fuels by 2030, amid rising pressure on planemakers to take climate change seriously. Regulators allow a 50-50 blend of sustainable and conventional fuels, and Boeing on Friday said it would work with authorities to raise the limit. Rival Airbus is considering another tack: a futuristic lineup of hydrogen-powered aircraft that would reach the skies by 2035. The aircraft manufacturers face growing public clamor to cut emissions in the aviation industry, which added more than 1 billion tonnes of carbon dioxide to the atmosphere in 2019, according to
RSS