Scientists have long studied how the gradual thawing of permafrost that occurs over decades in centimeters of surface soils will influence the release of carbon into the atmosphere. But Turetsky and an international team of researchers are observing something very different: the rapid collapse of permafrost that can transform the landscape in a few months through subsidence, flooding and landslides.
"We are seeing this sleeping giant awakening right in front of our eyes," said Turetsky, who holds the Canadian Research Chair in Integrative Ecology.
The team analyzes the importance of abrupt de-icing for estimates of carbon emissions, northern ways of life and climate policy in a commentary published in the May 2 issue of Nature. The researchers gathered the results of abrupt thawing studies of various environments in the permafrost zone to estimate the overall effect.
Permafrost affects about a quarter of the earth in the northern hemisphere. These frozen soils retain carbon in the biomass of dead plants, animals and microbes for millennia, preventing their decomposition and keeping them out of the atmosphere. As a result, soils in the permafrost region now contain twice as much carbon, approximately 1.6 trillion tons, as the content in the atmosphere.
"We work in areas where permafrost contains a lot of ice, and our field sites are being destroyed by the abrupt collapse of this ice, not gradually for decades, but very quickly for months or years," Turetsky said.
Co-author Miriam Jones, a geological researcher at the United States Geological Survey, said: "This abrupt thaw is changing forest ecosystems to thaw lakes and wetlands, resulting in a total transformation of the landscape that not only affects carbon feedback. to climate, but it is also altering wildlife habitat and harmful infrastructure. "
Turetsky, who describes the formation of melting lakes and landslides that trigger the massive movement of soil and sediments in rivers and streams, adds: "It is happening faster than anyone predicted, we show that the abrupt thawing of permafrost affects less of 20% of the permafrost region, but carbon emissions from this relatively small region have the potential to double the climate feedback associated with the thawing of permafrost. "
In its document, the team requests greater measurement and monitoring of Arctic permafrost, as well as better modeling and reporting of the effects of melting on the climate.
By: Preeti Narula