The Arctic’s summer of discontent is reaching a fever pitch this week. The heat wave that broke records in Europe is coming to Greenland and could melt enough ice to measurably raise global sea levels; wildfires are blazing on every continent, pumping carbon dioxide into the atmosphere; and sea ice is at record-low levels.
Whether the region is at a tipping point or threshold is up for debate scientifically, but it’s undeniable that we are staring at big, bad changes right now. And whether we cross the tipping point this year or 10 years from now, it’s what on the other side that’s even more unnerving: the unknown.
For decades, the Arctic has been galloping toward a more perturbed state. Carbon pollution has warmed the entire planet but cranked up the heat twice as fast in the Arctic. That’s led to a whole spate of menacing impacts, and the summer of 2019 has brought them all to the forefront.
“I cannot help but be heartbroken at how quickly these changes are taking place...and to watch helplessly as the most magical place on Earth burns.”
For starters on our apocalyptic tour of the Arctic, let’s talk about the fires that have engulfed much of the region. That includes Alaska, Canada, Russia, and even Greenland. The former three locations all have fires blazing in the boreal forest, a ring of dense forest around the northern reaches of the world just south of the Arctic tundra ecosystem. Merritt Turetsky, a fire ecologist at the University of Guelph, told Earther that it’s an ecosystem that relies on fire, but climate change has altered that relationship, with this year’s fire season a prime example of that.
“This fire season is unusual,” she said. “All around the world in multiple continents, the north is being shaped by fire. What’s more important is this is part of the long-term decadal trend of large fires happening more frequently than they did 50 years ago. We’re seeing a regime shift before our eyes.”
While there are 50 years of Arctic fire measurements, research using lake sediments can offer an even longer look at the region. By looking for charcoal and using various forms of isotope-based dating, scientists can stretch the fire record back thousands of years. Research published a few years ago found the fires in the boreal forest are burning at rates unprecedented in at least 10,000 years.
“Although my job as a scientist is to examine my data critically and in an unbiased way, I cannot help but be heartbroken at how quickly these changes are taking place... and to watch helplessly as the most magical place on Earth burns,” Melissa Chipman, a Syracuse researcher who worked on that paper, told Earther in an email.
When asked if we’re looking at a tipping point, she said “yes” while noting we’re seeing “there is a threshold of temperature and moisture conditions that dramatically exacerbate burning (i.e., a ‘tipping point’). The fires that are occurring in Alaska, Siberia, and even Greenland (!) are examples of recent weather conditions being dry enough and hot enough for fires to ignite and have biomass that is dry enough to burn.”
Thomas Smith, a fire expert at the London School of Economics, suggested that rather than a tipping point, this year’s fires represent more of a “threshold.”
“A tipping point would suggest that the situation is irreversible, which is not the case,” he told Earther. “Once the fuel moisture increases again, the chances of a fire will go down. These fires will certainly contribute to a positive feedback cycle, whereby the greenhouse gas emissions from peat fires (which cannot be sequestered by regrowth) can only exacerbate climate change and make future peat fires more likely.”
Indeed, the peat fires are perhaps the most worrying aspect of the fires, which released more carbon in June alone than Sweden does in an entire year. Boreal forests tend to do a great job sucking carbon out of the atmosphere and storing it in peat-rich soil. But rising temperatures are making those peat soils more susceptible to burning, including some that could smolder and last over the winter as so-called zombie fires (this is the actual term for them in Alaska).
“This is carbon that takes thousands of years to accumulate and... poof... it is gone,” Chipman said.
A wildfire in the Northwest Territories as seen on July 27. Image: Pierre Markuse (Flickr)
No matter how you slice it, the fires are indicative of what the future in Arctic looks like. Hotter, drier weather will allow more fires to burn. Turetsky said boreal forests – particularly the ones in North America that are home to coniferous trees – are “not going to look the same 50 years for now.” That could in turn reshape the relationship of fire to the forest and the forest to the climate as deciduous trees or grasslands show up to take their place. And while palaeoclimate research can provide some insights into what comes next, there really is no precedent for how fast the forest transformation in the Arctic is happening right now. If the fires of today feel scary, the fact that we don’t really know what fires of the future will be like is downright terrifying. It’s like trying to land a plane blind, with no pilot training.
The fires are only part of this summer’s story in the Arctic, though. Greenland is on its way to experiencing one of the most widespread surface melts on record since 1950, on the back of a massive heat wave. A weather balloon launch in northeast Greenland measured a high-temperature record for the lower atmosphere on Tuesday, with the heat expected to crank up over the island into the weekend. Forecasts for the ice sheet indicate that 60 percent of its surface could melt this week. That would be the second-largest melt, trailing only a July 2012 event when basically the entire ice sheet turned into a slushy mess.
According to Xavier Fettweis, a University of Liege polar researcher, the island could shed 40 million tons of ice this week, enough to raise every ocean on Earth 0.65 millimetres. Rivers running off the ice sheet are already roaring and could pose a particular danger in the coming days to communities downstream as the heat wave intensifies runoff. Fettweis noted this is what a “normal” summer will look like by 2050.
The Naujatkuat River in West Greenland running high in end of July, my gauging station is perched on the bedrock. With the exceptional heat wave coming I have my fingers crossed for it not being washed away. pic.twitter.com/JPofxDIELN
— Irina Overeem (@IrinaOvereem) July 30, 2019
The melt is driven by a weather event, but that fits with a larger worrying trend. The ice sheet is getting darker thanks to dust and soot from forest fires, allowing it to absorb more heat. In fact, it was soot from Russian fires that in part led to that 2012 meltdown. Mark Parrington, a fire scientist working at Europe’s Copernicus Earth Observation Programme, told Earther winds haven’t been blowing north during this year’s fires. That could be sparing the ice sheet and sea ice from even more widespread melt, though he noted he hadn’t computed any specific numbers as far as how much fire-flung gunk was ending up on the ice.
Research has indicated that melts like the one in 2012 could become an annual occurrence by century’s end as temperatures rise and more forests burn, darkening the ice sheet further.
The unending heat in the Arctic is also keeping sea ice at record lows for this time of year. This week’s blast furnace (by Arctic standards, anyways) will only further erode ice as it inches toward its annual minimum in September. And again, this is all in line with long-term trends that have seen the sea ice minimum shrink by roughly 13 percent per decade since the 1970s.
“Overall, this summer has not been surprising to me at all,” Zack Labe, a PhD candidate at the University of California, Irvine who studies the Arctic, told Earther. “We are seeing in real-time the effects of a warming Arctic with declines in sea ice area and thickness.”
The fact that none of this is surprising to scientists is hardly comforting news.
Featured image: Pierre Markuse (Flickr)