Extreme Heat the New Norm
The hottest summer day you remember from childhood could be the norm in a few decades; in fact it looks like the heat has already been cranked up.
"When scientists talk about global warming causing more heat waves, people often ask if that means that the hottest temperatures will become 'the new normal,'" said Noah Diffenbaugh, an assistant professor of environmental Earth system science at Stanford, in a press release.
"That got us thinking —- at what point can we expect the coolest seasonal temperatures to always be hotter than the historically highest temperatures for that season?" wondered Diffenbaugh.
Diffenbaugh is lead author of a study to be published later this month in the journal Climate Change. Stanford research assistant Martin Scherer co-authored the study.
"According to our projections, large areas of the globe are likely to warm up so quickly that, by the middle of this century, even the coolest summers will be hotter than the hottest summers of the past 50 years," said Diffenbaugh.
Within the next 20 to 60 years, if greenhouse gas levels continue to rise, summer temperatures are likely to rise irreversibly around the globe, with the tropics feeling the heat first, and parts of Africa, Asia and the Americas suffering unprecedented summer heat within the next two decades, according to Diffenbaugh's study. The middle latitudes, including Europe, China and the United States, will feel the heat within 60 years, they report.