In the Arctic, where summer sea-ice levels are crashing, a little extra snow doesn’t sound like it would be a bad thing. But in at least one corner of the Arctic, a new study shows that extreme snowfall was catastrophic, leading to breeding failures in all levels of the ecosystem in the summer of 2018.
For more than 20 years, researchers have carefully monitored the Arctic ecosystem around the research station at Zackenberg in northeast Greenland for over 20 years, according to a press release. When the snow melts away in June, the Arctic erupts into a riot of life, with plants poking out of the soil primed to bloom, insects emerging and hordes of shorebirds migrating long distances to the area to nest. While the success rate of each breeding season varies, life marches on—even in bad years.
But the summer of 2018 was different. By late July, snow still covered 45 percent of the landscape. At that point in the year, snow coverage should be closer to 4 percent on average, reports Jonathan Lambert at Science News.
“There were no birds singing, even the river was still frozen,” says Jeroen Reneerkens, avian ecologist at the University of Groningen and co-author of the new study in the journal PLOS Biology. “I was shocked.”
The snow stifled the normal rhythms of the Arctic. Many plants and animals were buried by the persistent snow. While some plants did manage to emerge and bloom, they did not have enough time to set seed before the cold returned.
Migratory birds—specifically little seaside birds called sanderlings—did not have enough insects to eat during the breeding season. Only a quarter of the average sanderling populations were accounted for, and those individuals were in bad shape. Most of them were very skinny birds, begging for scraps at the research station. The team only found one nest, which hatched extremely late, meaning its unlikely the chicks could grow strong enough for the journey back south. The team also failed to find any Arctic fox cubs or musk oxen calves.
“I try not to be sentimental, but it was scary,” co-author Niels Martin Schmidt, an arctic ecosystem ecologist at Aarhus University, tells Lambert. “In nearly 25 years of monitoring, we’ve never seen anything like this.”
Michael Le Page at New Scientist reports that it wasn’t just Zackenberg that received heavy snow. Extreme snowfall was widespread across the Arctic in 2018, though not many areas receive the same type of ecosystem monitoring as Zackenberg.
While ecosystems can typically bounce back from one bad year, two bad breeding seasons back-to-back is tougher to recover from. In 2019, the Arctic suffered from too little snow, rather than too much the year before. Without snowmelt, plants and animals had limited water to rely on. Researchers have not yet released an assessment of that breeding season.
As the global temperature continues to rise, prediction models show that more years of extreme conditions are likely to occur. While most species can survive a year or two of extremes, continued bouts of weird weather that animals aren’t adapted to could lead to some species extinctions.
“One non-breeding year is hardly that bad for high-arctic species,” Schmidt says in a statement. “The worrying perspective is that 2018 may offer a peep into the future, where increased climatic variability may push the arctic species to—and potentially beyond—their limits. Our study shows that climate change is more than ‘just’ warming, and that ecosystems may be hard hit by currently still rare but extreme events.”