Rising Temperatures Bringing Bigger Floods

摘要

In October and November 2000, floods soaked large swaths of England and Wales, causing losses estimated to exceed $2 billion. Now new research suggests that human-caused climate change, brought about by past emissions of carbon dioxide, almost certainly boosted the risk of these floods. Pardeep Pall of the University of Oxford in the United Kingdom and his colleagues ran thousands of climate simulations. In roughly half of them, they reduced atmospheric concentrations of carbon dioxide to levels measured in 1900, and they adjusted ocean temperatures and the amount of Arctic sea ice-which affects high-latitude weather patterns-accordingly. In the other simulations, they modeled modern conditions. Then they compared the rainfall amounts generated in both types of simulations. Finally, they fed the rainfall values into a model that assesses the potential for flooding.