IPCC Report: Global Warming and Changing Population Will Worsen the Toll of Extreme Weather
Maybe we should retire the term “global warming,” which makes climate change sound like a nice, pleasant bath. It’s true that climate change—caused chiefly by the rapid increase in manmade carbon emissions—will result in warmer temperatures, fewer cold days and longer and more intense heat waves. But the real damage, both economically and in human lives, is likely to be inflicted by an increase or amplification of extreme weather events—floods, storms, droughts.
The trouble is that attributing extreme events to climate change has always been challenging, which makes it that much more difficult to predict how weather will respond to warming. But scientists are getting better, and a new report (PDF) out today from the Intergovernmental Panel on Climate Change has a clear message: more carbon emissions will mean more dangerous extreme weather events. “We need to be worried,” said Maarten van Aalst, the director of the International Red Cross/Red Crescent Climate Centre and a lead author on the IPCC study, at a news conference in Kampala, Uganda. “Risk has already increased dramatically.”
Like the IPCC’s broad assessments of climate science—the most recent of which was released in 2007—this report gauges the degree of confidence scientists have in the different effects of a changing climate. That confidence varies: scientists are very sure that we are experiencing an increase in the number of hot days and nights on a global scale, and are certain that we’ll see rising temperatures in the decades to come. They’re sure that economic losses from weather- and climate-related disasters has increased as well, with annual losses reaching as high as $200 billion. They’re fairly sure that the frequency of heavy storms will increase in the 21st century, and certain that sea levels will rise, impacting extreme coastal water levels.
But the researchers who put together the IPCC report are also honest about the areas where climate science is less confident—such as with tropical storms. They note that it is likely the “global frequency of tropical cyclones will either decrease or remain essentially unchanged,” though there is some confidence that existing storms will become stronger. On the whole the new report—perhaps in response to criticisms of the last IPCC climate assessments, which contained a few embarassing mistake—is a more measured take on the state of climate science and extreme weather events, though that has some critics on the other side fuming that the threat has been watered down.