Predicting the onset and effects of climate change involves a complex mashing of the natural and the man made, calculating things like solar radiation and plate tectonics.
But while climate models are become more advanced with each passing year relatively little is known about one of the scariest side-effects of global temperature rise: the melting of banks frozen land, otherwise known as permafrost.
You can define permafrost as any bank of soil that’s been frozen (at below 0 degrees) for more than two years, but much of these frozen land expanses have been frozen for thousands of years—some since before the last Ice Age. When soil freezes it captures carbon and wraps it in a cryogenic holding place. When it warms, the carbon is released from its holding pattern.
The problems are exacerbated in Arctic areas, according to Lars Ola Nilsson, a scientist studying soil at Bioforsk.
“The closer you get to the poles, principally the more carbon there is,” says Nilsson. “When you heat it up the composition will turn over and it will increase, the biological and physiological things; the enzymes want to have some temperatures.”
Last December the United Nations Environment Program announced that permafrost emissions had reached the point of concern; scientists predicted the melt could amount for about 40 percent of greenhouse gas emissions. But emissions from warmed soil might be extra destructive because of an additional ingredient: rotting plants and small animals add a double-dose cocktail of methane. In a 2011 study published in the Nature, climate modelers calculated that permafrost thaw would release the same amounts of carbon as deforestation, but have 2.5 times more influence over climate because of the addition of methane.
Though scientists have modeled the rate of permafrost melt, Nilsson is setting out to model its impacts in a new study on the warming of Arctic meadows.
“Agricultural meadows are quite fascinating here so far north,” says Nilsson. “We will warm up some plants and see what happens.”
Nilsson and his laboratory team have carved out eight meadows in varying climates—several in the botanical research gardens at Bioforsk—and will warm the fields, measuring the emissions of gasses and the breakdown of plant life that results. (A thermal infrared camera will also measure plant stress.)
The research is particularly timely in light of a recent roster of evidence hinting that permafrost might be a particular problem in the North. Earlier this year scientists found that light exposure—say from the midnight sun—increases conversion of bacteria to carbon from warmed soil. Global temperature rise is also taking effect in Northern soils, which now foster an additional 40 days of growing season over the last 30 years. Combine the additional warmth with proximity—permafrost covers about 63 percent of Russia—and the problem gets toxic. Last month climate scientists argued that increased monitoring is needed in the Arctic because of the susceptibility of the location to both climate change and pollution.
Though the research is just beginning, from past work Nilsson expects that the methane released from the break down of permafrost will made up for the increased photosynthesis from plants exposed to extra warmth and light. He also plans to monitor the soil to see whether the melt releases heavy metals and pollutants into the surrounding area—and in turn whether those pollutants will be taken up by the plants.
And soil, it turns out, is a great storyteller.
“Soil microbe communities can be used as sensitive indicators,” says Nilson. “You can see almost direct indicators in what species there are, what organisms there are in the dirt.”
In addition to predicting fallout, the study will also test a solution by applying Biochar—a kind of charcoal that is being explored for its carbon capturing impacts—to an experimental set of the fields.
“We don’t have much permanently frozen soils in Norway but you look to Russia and there are huge areas of soils that are permafrost,” says Nilsson. “There is a risk that they would thaw…that’s sort of a cascade effect."
