A new study by German scientists suggests that several episodes of extreme weather in recent years can be directly contributed to what are described as "planetary waves" of warm air flows caused by increased heat on the planet driven by human industrialization and carbon emissions.
In a paper published in the US Proceedings of the National Academy of Sciences on Monday, researchers from the Potsdam Institute for Climate Impact Research (PIK) found that traditional air flow patterns that oscillate between the north pole and the tropics have slowed in the last three decades causing shifts in climate patterns that contributed to devastating heatwaves across Europe in 2003, historic floods in Pakistan in 2010, and other extreme events in Russia, the U.S., and elsewhere.
"During several recent extreme weather events these planetary waves almost freeze in their tracks for weeks," wrote Vladimir Petoukhov, lead author of the study. "So instead of bringing in cool air after having brought warm air in before, the heat just stays."
In a review of the study, Agence France-Presse adds:
In an ecosystem ill-adapted to long periods of extreme heat, the stress can be disastrous, with high death tolls, forest fires, and agricultural losses.
For instance, during Russia's 2010 heat wave -- the worst in its recorded history -- wildfires spread out of control, killing dozens of people, burning down thousands of houses and threatening military and nuclear installations.
Global warming, despite its name, is not uniform across the planet. At the poles the bump in temperatures -- amplified by shrinking snow cover and ice -- is greater than in the swathes between, the scientists explained.
This reduces the temperature differences between the Arctic and the middle latitudes, which affects the flow of air around the globe.
In addition, continents heat and cool more rapidly than large bodies of water, the scientists said.
Though the scientists say that the period of study was too short to make accurate predictions about the future climate, they called the evidence "quite a breakthrough" and promised to build of this work in future research.