Sandra Angers-Blonde
The North Pole is not going that hot. This is because it is in fact also hot. It heats up at least twice as fast as the rest of the planet, causing angry feedback loopholes that can accelerate change. Ice, for example, is more reflective than soil, so the region absorbs more solar energy as it melts. Darker vegetation grows in northern countries and absorbs even more solar heat. And when permafrost thaws, it releases greenhouse gases that further heat the climate.
The Arctic has become so bizarre that lightning – a phenomenon with hot weather most common in the tropics – is now striking near the North Pole. And according to new modeling, the electric bombardment of the region will only get worse. By the end of the century, the number of lightning regions across the Arctic could more than double, causing a shocking cascade of ignition effects – namely more veld fires and more warming. “The Arctic is a rapidly changing place, and it’s an aspect of the transformation that I’m not sure, but got a lot of attention from, but it’s actually consequent,” said UCLA climate scientist Daniel Swain, who is not involved. was not. in the research.
To make thunderstorms, you need a lot of heat. As the sun warms the land, hot air and moisture rise in the atmosphere. At the same time, cold air sinks into the system. This creates a swirling mass, known as a deep convective cloud, which in turn creates electric charges that become lightning.
This is normal in the tropics, where there can be a lot of heat, but the Arctic must be cold enough to better withstand this large-scale increase in warm air. Not anymore, apparently. “As the surface warms, you will have more energy to push air into the high latitude,” said UC Irvine climate scientist Yang Chen, lead author of a new article in Nature Climate changedescribe the modeling. “And because the atmosphere is warmer, it can contain more water vapor.”
If you put it together, you have big, flashing storms that are now moving within 100 miles of the North Pole. (Scientists can determine the strikes in the remote region with a worldwide network of radio detectors: if a bolt falls to the ground, it actually turns into a kind of radio tower that blows out a signal.) And where you have lightning, you We has the potential for fire, especially when the North Pole gets hot and dries. “The heat wave of 2020 in the Russian North Pole shows how – even at high latitudes – really hot weather conditions can arise which can lead to fires that burn intensely and can become very large,” says Isla Myers-Smith, an ecologist of the University of Edinburgh who studied the region but was not involved in this new work. “Many areas burned in the Russian North Pole during the 2020 fire season.”
An arctic wildfire can chew through two main types of material, both of which are problematic. Much of the soil is peat, essentially concentrated carbon from plant material accumulated over thousands of years. When this ground burns, the fire smolders deeper into the ground, releasing incredible amounts of greenhouse gas that would have been safely locked away in a cooler, wetter North Pole. These flames are so persistent that scientists have called them zombie fires: they will burn for months underground and even snow, to re-ignite as a new surface fire as soon as the snow melts.
The other flammable material in the Arctic is aboveground vegetation. Grasses dominate on the tundra, but scientists are increasingly finding shrubs on their grass to muscle together. “Shrubs like to grow where there have been disturbances, such as fire and permafrost thawing. So more fire in the tundra can mean more shrubs, ”says Myers-Smith. “Shrubs grow more when the summer is warmer and when the water is not restricted. Therefore, we expect the shrubs to increase with future warming in the tundra.” If we look at sediment records, Myers-Smith can actually see how warmer times in the north encouraged the growth of more shrubs and led to more fires.
If this further complicates these feedback loops, more shrubs in turn will provide a warmer Arctic area thanks to the declining reflection of the landscape or the albedo. When bright white snow covers a grassy tundra, it reflects the sun’s energy. But if shrubs take over the landscape, more dark vegetation will protrude above the snow layer and absorb more heat. The albedo effect is especially sharp in summer, when the North Pole is bathed in 24 hours of sunlight. “The Arctic is a strange place compared to what most of us are used to at lower latitudes, in the sense that the solar radiation there is very intense, but only for a short period of time,” says Swain. “And for the rest of the year, it can hardly exist.”
A darker, warmer landscape means the permafrost melts more. Also, more veld fires will melt the permafrost by burning moss and other organic matter that sits on top of the frozen soil and preventing it from heating up. The extra bad news: Arctic permafrost contains a third of all the carbon stored in the world’s soil.
Chen and his colleagues also predict that forests could move further north if veld fires burn grass and shrubs away. A tree roof will further darken the landscape and possibly lead to more thunderstorms and lightning: if a forest absorbs more of the sun’s energy, the air and moisture will rise from it to create the deep convective clouds. Knal! There’s your lightning – and possibly another fire that will chew through the grass of a nearby tundra, making room for more shrubs or trees and consequent warming. And so the cycle will continue.
Scientists studying the North Pole, such as Myers-Smith, are experiencing first-hand the toll of Arctic thunderstorms: we are talking about 200,000 strikes every summer. “Sometimes we get caught out on the tundra when the thunderstorms roll in,” Myers-Smith says. ‘Out there you’re the longest thing, which means lightning is a real danger. We found ourselves running from the high ground and rushing back to camp to escape from the storm, which was often exhausted by the escape and drenched by the rain. ”
Yet that rain can – at least in part – temper the feedback loops that are heating up the North Pole. A ‘dry’ thunderstorm that produces lightning but not water is a particular wildfire hazard, as Californians learned last summer because there is nothing to put out the sparks. But as long as a storm also produces rain, ‘it can not lead to actual combustion’, says Chen. “It’s just lit, and then the rain lets the inflammations go.”
Chen also says that accelerated growth of vegetation can help bind carbon, although it will not be enough to compensate for the amount that can be released when the soil warms up. The loss of permafrost will unlock astonishing amounts of carbon that has been trapped in the soil for thousands of years. The only solution to restore some balance is that humanity will reduce emissions – and quickly.
This story originally appeared on wired.com.