Spiraling Out of Control: Fires in the Arctic

This summer, fires raged in Siberia that spanned between 2.7 and 3.3 million hectares in Russia alone, releasing more energy this June than the past 9 Junes combined. The fires have released more CO2 than Sweden’s average yearly carbon emissions. In July alone this figure came to 79 megatons, making this summer the highest  in 17 years. The cloud of soot and smoke billowing off of these fires, on the other hand, has reached as far as Greenland and covers a total area of 5 million square kilometers: 500,000 square kilometers greater than the size of the E.U.

Fires in boreal forests are usually not simply a catastrophe, and are in fact a natural part of cycles in these ecosystems that have occurred since long before humans existed. As weather in the arctic is often too cold for speedy decomposition, forest fires are one way that dead leaves and debris are reclaimed as nutrients for trees in these regions. Many species of these trees have also evolved around fires, either by developing fire resistant bark and seeds or extremely flammable ones, with the latter’s reproduction and spread being partially dependent on the incidence of forest fires. Boreal forest fires also help trap carbon by creating a layer of burned material below which carbon is trapped, generating “legacy C” pools. Thanks to this mechanism, among others, boreal forests are a net carbon sink, meaning they absorb and store more carbon than they release into the atmosphere. Boreal forest fires, then, contribute to many natural cycles generating beneficial regional effects, while also aiding in stabilizing global climate conditions.

The problem, then, is not that these fires are inherently unnatural catastrophes; rather, it is that the natural cycles these fires contribute to are being transformed through global conditions into spirals that are rapidly drawing the climate into a drastically different state. Point in case: most of the fires this summer were ignited by lightning, which would normally be unsurprising as that is the natural source of ignition for many forest fires. Yet increasing global and regional temperatures make lightning far more likely, an effect particularly pronounced in arctic latitudes where heating is “three times faster than other parts of the planet.”

This heating also means the rapid melting of sea ice, a phenomenon that is again exacerbated by forest fires. The massive clouds of soot and smoke deposit ash and paint the sea ice they pass over, reducing their albedo, or reflectivity, causing them to absorb more of the sun’s rays. This accelerates their melting, and with it the warming of arctic regions.

This warming then leads to other damaging factors, such as increasing forestation in the arctic by providing amenable, though drier, conditions for boreal trees. Though more trees may initially sound good, this merely means more and drier fuel, which can help forest fires to help fires get out of hand. It is also particularly significant that a large portion of arctic regions are home to peatlands, natural deposits of carbon holding as much carbon as has been emitted by humans since the start of the industrial revolution. With greater forestation, these peatlands become both drier and covered in easily flammable fuel.

These cycle disruptions also generate feedback loops. Research has shown that peatland becomes increasingly drier, more flammable, and slower at producing peat, thus more prone to absorbing carbon from the atmosphere when subjected to repeated fires as this strips away protective layers of vegetation and ensures that each new fire digs deeper into the peat reserves. Recent fires have been shown to be burning such reserves, some of which are over 1,000 years old.  Areas around scars produced by such fires see accelerating melting of permafrost, which normally acts as a protective layer over peatland against forest fires and general loss of carbon to the atmosphere. All of these effects contribute to the greater incidence of forest fires, and to increased carbon emissions driving warmer and drier weather worldwide.

In some ways, these developments are not surprising – the increase of forest fires was predicted by scientists over a decade ago. Yet disturbing extant cycles generates feedback loops that make future change more rapid and potentially more unpredictable. Furthermore, neither the causes nor the effects are limited regionally. The point, then, should be this: Events like the Siberian wildfires must be a sobering call to global action. Far from being unusual tragedies, they are instead likely to be signs of further acceleration toward a point of no return. We have limited time to solve the climate change crisis, and the more we wait, the faster we hurtle towards it. As has been emphasized by many experts, transformative global change is needed – and if we wait to deliver it, the climate may not.

 

Image courtesy of Flickr. Originally published by S&S on November 7, 2016.

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