When rain—not snow—fell on the highest point of Greenland’s ice sheet this August for the first time in recorded history, it was considered a worrying anomaly related to the regions’ changing climate. Now, a new study led by Canada’s University of Manitoba and co-authored by scientists at the U.S.-based National Snow and Ice Data Center (NSIDC) shows that it’s not an outlier but a harbinger of things to come. More rain than snow will start falling in the Arctic, according to the report which was published in the journal Nature Communications on Nov. 30, and the transition is likely to occur decades earlier than previously thought. Projections from the latest models show an anticipated steep increase in Arctic precipitation—mostly rain—starting as early as 2050, instead of 2070 as the original modeling showed. The shift is occurring due to rapid warming, sea ice loss, and changes in weather patterns caused by increasing global temperatures.
Some of the ramifications of increased rainfall are more obvious than others: in the Arctic, there will be a reduction in snow cover, increased permafrost melt and higher incidences of flooding in river basins. Long term, reduced snow cover contributes to the albedo effect, in which dark terrain absorbs more of the sun’s heat, further increasing warming via an ongoing feedback loop. Thawing permafrost releases methane, a potent greenhouse gas that also contributes to continued global warming in another feedback loop.
“The fact that we’re getting rainfall on the summit of Greenland right now, and that we’re maybe going to get more rainfall into the future—it kind of staggers me,” says lead researcher Michelle McCrystall, a postdoctoral fellow in University of Manitoba’s Centre for Earth Observation Science. “If we continue the trajectory, a lot of issues might happen even faster than what we’ve projected.”
Read more: Why a Warming Arctic Has the U.S. Coast Guard Worried About the Rest of the Country
Meanwhile, the report notes, increased rainfall affects soil moisture and groundwater, upsetting the underground fungal networks that support arctic flora as well as the animals, like wild caribou, reindeer, and muskoxen, that depend upon it for survival in harsh winter conditions. Lichen, for example, can feed grazing animals all winter long when grasses are hard to find, but it depends on a delicate ecosystem easily disrupted by excess moisture. Rain in cold conditions could be equally devastating if it freezes into layers of ice and prevents animals from foraging for food. “The issue facing us today is that the Arctic is changing so fast that Arctic wildlife might not be able to adapt,” said Mark Serreze, co-author of the study and director of the NSIDC. “It’s not just a problem for the reindeer, caribou and musk ox, but for the people of the north that depend on them as well.”
Of course, there is an alternative to the nightmare scenario of a North Pole without reindeer. The paper’s research team notes that if we can keep the planet from warming more than 1.5°C since pre-industrial levels, we have a chance of keeping the rain at bay. But current policies presently in place around the world are projected to result in about 2.7 degrees of warming, according to the Carbon Action Tracker. “The new models couldn’t be clearer,” says co-author professor James Screen of the department of mathematics and Global Systems Institute at the University of Exeter. “Unless global warming is stopped, the future Arctic will be wetter; once-frozen seas will be open water, rain will replace snow.” And the Arctic as we know it will never be the same again.
