Human influence on climate dates back to 1930s, new research finds
|Humans have triggered the last 16 record-breaking hot years experienced on |
Earth (up to 2014), with our impact on the global climate going as far back as 1937,
a new study finds. Shown here a dust storm in Texas, 1935
"Everywhere we look, the climate change signal for extreme heat events is becoming stronger," said Andrew King, a climate extremes research fellow at the University of Melbourne, Australia and lead author of the study. "Recent record-breaking hot years globally were so much outside natural variability that they were almost impossible without global warming."
The researchers examined weather events that exceeded the range of natural variability and used climate modelling to compare those events to a world without human-induced greenhouse gases. The study was accepted for publication yesterday in Geophysical Research Letters, a journal of the American Geophysical Union.
According to the new study, record-breaking hot years attributable to climate change globally are 1937, 1940, 1941, 1943-44, 1980-1981, 1987-1988, 1990, 1995, 1997-98, 2010 and 2014.
|This animation shows the warming trend from the 1950s to 2013, where higher than|
normal temperatures are in red, and lower than normal temperatures in blue
Aerosols in high concentrations reflect more heat into space, thereby cooling temperatures. However, when those aerosols are removed from the atmosphere, warming returns rapidly. The researchers observed this impact when they looked at five different regions: Central England, Central Europe, the central United States, East Asia and Australia.
There were cooling periods, likely caused by aerosols, in Central England, the central United States, Central Europe and East Asia during the 1970s before accelerated warming returned, and aerosol concentrations also delayed the emergence of a clear human-caused climate change signal in all regions studied except Australia, according to the study.
"In regards to a human-induced climate change signal, Australia was the canary in the coal mine for the rest of the world," King said.
Source: American Geophysical Union [March 08, 2016]