Climate change models have dramatically underestimated the extent to which global warming will raise temperatures, scientists warned on Monday.
The flaw means existing predictions for temperature rises are inaccurate and will have to be revised upwards by as much as 2oC, suggesting the world could experience a hike of up to 7.7oC by the year 3000.
British efforts to combat climate change have focused on preventing carbon dioxide levels rising above 450 parts per million, equivalent to a rise of 2oC. If the world warms by more than this, many climate experts believe fragile ecosystems will be pushed beyond their "tipping point," triggering runaway global warming.
The flaw came to light during a study of the effects of global surface temperatures on atmospheric carbon dioxide levels. Scientists have long known that greenhouse gases raise temperatures by insulating the planet. But a less well known mechanism is that the warmer the planet gets, the more carbon dioxide is released naturally by soil and oceans. The result is a mechanism where atmospheric carbon dioxide creates warming that causes even more carbon dioxide to be released.
Peter Cox, scientific director for climate change at the Center for Ecology and Hydrology in Dorset, southwest England, with researchers from the US and the Netherlands, used ice cores from the Antarctic to study carbon dioxide levels trapped during a period called the Little Ice Age, from 1550 to 1850. They found carbon dioxide increased rapidly with warming, as soils decomposed faster and oceans lost more of the gas.
Because scientists have been unable to quantify the effect before, it has not been included in many climate models. But when it is taken into account, it lead to carbon dioxide levels that boosted temperatures by between 15 percent and 78 percent.
A recent report published by the Intergovernmental Committee on Climate Change found that carbon dioxide levels were likely to double pre-industrial levels by 2050. The latest research pushes those estimates to between 1.6oC and 6oC, Geophysical Research Letters reports.
Lead author Margaret Torn, of the Lawrence Berkeley National Lab, said: "To predict the future you have to guess how much carbon dioxide levels will go up. That depends on the biggest uncertainty of all, what humans do."
Nearly half of China’s major cities are suffering “moderate to severe” levels of subsidence, putting millions of people at risk of flooding, especially as sea levels rise, according to a study of nationwide satellite data released yesterday. The authors of the paper, published by the journal Science, found that 45 percent of China’s urban land was sinking faster than 3mm per year, with 16 percent at more than 10mm per year, driven not only by declining water tables, but also the sheer weight of the built environment. With China’s urban population already in excess of 900 million people, “even a small portion
‘IN A DIFFERENT PLACE’: The envoy first visited Shanghai, where he attended a Chinese basketball playoff match, and is to meet top officials in Beijing tomorrow US Secretary of State Antony Blinken yesterday arrived in China on his second visit in a year as the US ramps up pressure on its rival over its support for Russia while also seeking to manage tensions with Beijing. The US diplomat tomorrow is to meet China’s top brass in Beijing, where he is also expected to plead for restraint as Taiwan inaugurates president-elect William Lai (賴清德), and to raise US concerns on Chinese trade practices. However, Blinken is also seeking to stabilize ties, with tensions between the world’s two largest economies easing since his previous visit in June last year. At the
UNSETTLING IMAGES: The scene took place in front of TV crews covering the Trump trial, with a CNN anchor calling it an ‘emotional and unbelievably disturbing moment’ A man who doused himself in an accelerant and set himself on fire outside the courthouse where former US president Donald Trump is on trial has died, police said yesterday. The New York City Police Department (NYPD) said the man was declared dead by staff at an area hospital. The man was in Collect Pond Park at about 1:30pm on Friday when he took out pamphlets espousing conspiracy theories, tossed them around, then doused himself in an accelerant and set himself on fire, officials and witnesses said. A large number of police officers were nearby when it happened. Some officers and bystanders rushed
Beijing is continuing to commit genocide and crimes against humanity against Uyghurs and other Muslim minorities in its western Xinjiang province, U.S. Secretary of State Antony Blinken said in a report published on Monday, ahead of his planned visit to China this week. The State Department’s annual human rights report, which documents abuses recorded all over the world during the previous calendar year, repeated language from previous years on the treatment of Muslims in Xinjiang, but the publication raises the issue ahead of delicate talks, including on the war in Ukraine and global trade, between the top U.S. diplomat and Chinese