Hundreds of thousands of East Coasters suffered through hot and sticky climates for much of July, as temperatures reached record highs in some places. Although these types of extreme heat waves are unusual, they will become more frequent and severe across the globe in the next 30 years, and there's nothing that can be done about it, according to a new study from a team of international researchers.
Most environmental and climate researchers believe that extreme heat waves are the result of global warming and high levels of carbon dioxide being released into the atmosphere. But no matter what actions are taken to reduce carbon dioxide emissions, intense summer heat waves are expected to double by 2020 and quadruple by 2040, according to a study to be published Thursday in the journal "Environmental Research Letters."
"We find that up until 2040, the frequency of monthly heat extremes will increase several fold, independent of the emission scenario we choose to take," said lead author Dim Coumou, of the Potsdam Institute for Climate Impact Research, in a statement. "Mitigation can, however, strongly reduce the number of extremes in the second half of the 21st century."
Coumou, along with Alexander Robinson of the Universidad Complutense de Madrid, used a computerized climate model to predict how many extreme heat waves will occur over the next few decades. Dubbed "3-sigma" events, these heat waves have unusually high temperatures that are three standard deviations from the historical average, and are expected to become the norm over the course of the 21st century.
In 2010, a 3-sigma heat wave in Russia, for example, brought temperatures as high as 104 degrees Fahrenheit. In Australia, an extreme heat wave during the summer months of January and February in 2009 caused temperatures to spike above 110 degrees in some places.
And the more intense "5-sigma" heat waves, which are virtually non-existent today, are expected to occur in about 3 percent of the world by 2040.
But even past the year 2040, if carbon dioxide emissions are high, 3-sigma heat waves will be common in 85 percent of the world, and 5-sigma heat waves will be present in about 60 percent of the world by the year 2100.
Coumou said extreme heat can bring serious environmental and health-related consequences, often causing heat-related deaths, forest fires and damage to agriculture.
The Natural Resources Defense Council estimates that more than 150,000 people in the United States could die by the end of the century due to excessive heat, for example.
"An increase in frequency is likely to pose serious challenges to society and some regions will have to adapt to more frequent and more severe heat waves already in the near-term," Coumou said.