Half a degree Celsius of global warming has been enough to increase heat waves and heavy rains in many regions of the planet, researchers reported on Friday.
Comparing two 20-year periods — 1960-79 and 1991-2010 — between which average global temperatures jumped 0.5 degrees Celsius (0.9 degrees F), scientists found that several kinds of extreme weather gained in duration and intensity.
The hottest summer temperatures increased by more than 1 degree C across a quarter of the Earth’s land areas, while the coldest winter temperatures warmed by more then 2.5 C.
Outside the bounds
The intensity of extreme precipitation grew nearly 10% across a quarter of all land masses, and the duration of hot spells — which can fuel devastating forest fires — lengthened by a week in half of land areas. These changes were well outside the bounds of natural variability, according to the study, published in the journal Nature Climate Change .