Extreme Weather Boosted By Half-Degree Warming

Half a degree Celsius is all it took to increase the occurrence of heat waves and heavy rainfalls worldwide, according to researchers. Image credit: cjohnson7 / CC BY 2.0Half a degree Celsius is all it took to increase the occurrence of heat waves and heavy rainfalls worldwide, according to researchers.

Publishing their findings in the journal Nature Climate Change, researchers compared two 20-year periods (1960-1979 and 1991-2010) between which average global temperatures increased 0.5 degrees C (0.9 degrees F) and determined that the different types of extreme weather increased in both duration and intensity.

Additionally, researchers found that the hottest summer temperatures increased by more than 1 degree C (1.8 degrees F) across one quarter of the Earth’s land masses and the colder winter temperatures warmed by over 2.5 degrees C (4.5 degrees F).

Likewise, extreme precipitation intensity increased by almost 10 percent (across one quarter of the Earth’s land masses) while the length of hot spells increased by a week in half of the Earth’s land masses.

"We have to rely on climate models to predict the future," said lead author Carl-Friedrich Schleussner, a researcher at the Potsdam Institute of Climate Impact Research.

"But given that we now have observational evidence of around 1 C warming, we can also look at the real-life impacts this warming has brought," he said in a statement.

"With the warming the world has already experienced, we can see very clearly that a difference of 0.5 C really does matter," said co-author Erich Fischer, a scientist at ETH Zurich in Switzerland.