The melting of the permafrost in the Canadian and Russian Arctic may cause additional increase of average temperatures on Earth by 1.69 degrees Celsius by 2300, even if greenhouse gas emissions are completely stopped, say climate scientists in a paper published in the journal Nature Geoscience .
It is believed that other areas of tundra and permafrost have accumulated over its lifetime of about 1.7 trillion tons of carbon in the organic remains of animals and plants. For comparison, the Earth's atmosphere contains about half as much carbon, and releasing even a part of these stocks could have catastrophic consequences for the Earth's climate.
Group of climate scientists led by Andrew McDougall (Andrew MacDougall) from the University of Victoria (Canada) review what effects may occur after thawing of permafrost in the coming years with the global climate model ESCM.
As explained by McDougal and his colleagues, the model accounts for the effect of climate change on permafrost, and how the released carbon dioxide and methane accelerate this process.
During the simulation the authors changed the amount of anthropogenic CO2, watching for changes in the reduction of emissions to zero and removing all restrictions on the production of greenhouse gases. In each case, the scientists studied the rise in the concentration of methane and carbon dioxide and reduction of permafrost.
It turned out that all the scenarios lead to almost the same effects — melting permafrost will increase the proportion of CO2 in the atmosphere at 50-100 parts per million by the end of this century.
Increase in the concentration of CO2 will result in an additional increase in average temperature of the planet at 0,23-0,39 degrees, depending on the efficiency of melting permafrost. As a result, the melting of permafrost will increase the proportion of carbon dioxide in the atmosphere at 44-279 ppm, the "warm up" the planet to 0,37-1,69 degrees Celsius, depending on the parameters of the simulation.
According to scientists, the reduction of emissions by 90% from today's human contribution to global warming and artificial removal of CO2 from the atmosphere will not be able to stop the melting of permafrost and subsequent "acceleration" of climate change.
"In the event that the amount of CO2 that will be released from the thawed soil exceeds the ability of the ocean to absorb excess carbon dioxide, carbon dioxide concentration in the atmosphere will increase. As a result, the soil will warm even more, and will stand out even more CO2" — written climatologists .
The researchers believe that such alarming findings should encourage scientists and relevant government agencies to strengthen the monitoring of permafrost and regularly measure the amount of CO2 that is released to the melted parts of the Arctic tundra, and other landscapes.