A new analysis of observed temperatures shows the Arctic is heating up more than four times faster than the rate of global warming. The trend has stepped upward steeply twice in the last 50 years, a finding missed by all but four of 39 climate models.
“Thirty years is considered the minimum to represent climate change,” said Petr Chylek, a physicist and climate researcher at Los Alamos National Laboratory and lead author of the study in Geophysical Research Letters. “We decreased the time interval to 21 years. At that smaller time scale and, contrary to previous investigations that found the Arctic amplification index increases in a smooth way, we observed two distinct steps, one in 1986 and a second one in 1999.”