New climate modeling shows the transition could happen earlier than scientists had previously projected. Michelle McCrystall, the lead author of the study and climate researcher at the University of Manitoba in Winnipeg, told CNN that earlier modeling suggested it wouldn’t occur until between 2090 and 2100.
“But with the new set of models, this actually has been pushed forward to about between 2060 and 2070, so there’s quite a jump there by 20 years with this early transition,” she said.
The study notes that the increase in rainfall is due in large part to the loss of sea ice. More open water and warmer air temperatures mean more evaporation, which primes the atmosphere for a wetter Arctic. The researchers say a rainfall-dominated Arctic has the potential to destabilize Greenland’s ice sheet mass balance, triggering a global rise in sea levels.
“Things that happen in the Arctic don’t specifically stay in the Arctic,” McCrystall said. “The fact that there could be an increase in emissions from permafrost thaw or an increase in global sea level rise, it is a global problem, and it needs a global answer.”
“If we did stay within this 1.5-degree world, the Arctic could remain snow-dominant by the end of the century, but some parts probably still will transition,” and some of them are already transitioning, McCrystall said. “But we are still on the trajectory of a 3-degree world.”
Though scientists not involved with the study overwhelmingly agreed that the Arctic is undergoing rapid change amid the climate crisis, some expressed caution about the study’s results and specifically pointed to the critical need for more observations and more research.
Tim Palmer, a climate physicist at the University of Oxford, said future Arctic precipitation trends need “more careful quantification.”
“All this points to the need for high-quality observations of precipitation for regions such as the Arctic and the development of a new class of high-resolution climate model, with smaller biases and more realistic estimates of natural variability on the regional scale,” Palmer said in a statement. “Together these will give us more confidence in the impact of carbon emissions on precipitation in places like the Arctic. We need these urgently if they are to impact on mitigation policy.”
Bob Spicer, a professor emeritus at the Open University who spent years studying past climates of the Arctic, said “this research is entirely in line with what the fossil record tells us the Arctic was like during previous episodes of global warmth.”
7 billion tons of water
“While it’s inevitable that Arctic rainfall will increase as the climate warms, rains are also likely to become more intense,” Mark Serreze, co-author of the study and director of NSIDC, told CNN. “It’s a nasty one-two punch to an ecosystem already reeling in the face if rapid environmental change.”
While the projections aren’t definitive, McCrystall said more rain events in Greenland — and the Arctic region as a whole — are expected to occur the more humans continue to pump more greenhouse gases into the atmosphere.
“With the oceans getting warmer and [the Greenland] rainfall event that has happened, there are some indications that maybe things are even more extreme or changing much more rapidly than even our models are projecting, potentially,” she said.
But “the fact that everything is shifting to show that there’s greater extremes in precipitation, that in itself is an indication of human-induced climate change for sure,” McCrystall said.