Accurate understanding of dynamics Permafrost It is necessary to evaluate and mitigate the impacts that may arise when they deteriorate in the future. However, current forecasts involve a great deal of uncertainty.
Studies of how they responded historically during Earth’s recent warm periods are useful for exploring potential future behavior and assessing uncertainty in future projections. Now, an international team of scientists, after comparing current climate trends with the planet’s climate 3 million years ago, has found this Most of the permafrost near the Earth’s surface could disappear by 2100.
The team found that the amount of near-surface permafrost could decline by 93% compared to the pre-industrial period of 1850 to 1900. This is under the most extreme warming scenario in the latest IPCC report.. By 2100, permafrost will form near the Earth’s surfacewithin the top 10 to 13 feet of the soil layer, It may have existed only in the eastern Siberian highlands, the Canadian Arctic Archipelago, and the northern tip of Greenland, as it did in the mid-Pliocene warm period.
Research that was just published in Proceedings of the National Academy of Sciences (PNAS), was directed by Donglin Guo of the Chinese Academy of Sciences and Nanjing University of Information Science and Technology. Scientists from the United States, Russia, the United Kingdom, Germany, Japan, Canada, the Netherlands, France and Sweden collaborated in the research.
“Our study suggests an area of near-surface permafrost significantly smaller than that of the geological past, under climate conditions similar to those expected if global warming continues unabated,” said Professor Emeritus Vladimir Romanovsky, a specialist at the Fairbanks Geophysical Institute. The University of Alaska, which is among the co-authors, is also a leader in permafrost research.
“The loss of much near-surface areas over the next 77 years will have wide-ranging impacts on human livelihoods and infrastructure, on the global carbon cycle, and on surface and subsurface hydrology.”
“This research – continued the specialist – is creating Another alarm sounded More about what’s going on with Earth’s climate. Climate simulations for the mid-Pliocene warm period are similar to climate projections for the end of this century under a fossil fuel-based development trajectory in the latest report from the Intergovernmental Panel on Climate Change (IPCC). This path is the darkest of the five paths offered to future society.
Simulations of the mid-Pliocene warm period and projections of permafrost extent in 2100 focus only on near-surface permafrost, which is less resilient to global warming than deep permafrost. Ten computer models predict that the Earth will lose about 77% of that permafrost by 2100, compared to 1995-2014, according to the Intergovernmental Panel on Climate Change’s fossil fuel-based development pathway if surface air temperatures rise by 10 degrees Celsius.
The paper’s authors chose to compare Earth’s projected future to the mid-Pliocene warm period, which occurred about 3 million years ago, because it is the most recent period of sustained global warming in the planet’s geologic history.
Scientists have little direct information about permafrost in the Northern Hemisphere during the mid-Pliocene warm period. To overcome this, they analyzed other factors, such as vegetation composition and special soil properties, to reconstruct surface air temperature records. From this indirect evidence, they predicted the extent of permafrost in the mid-Pliocene warm period.
Using computer models, they found that the global average annual surface temperature at that time was 14 to 15 degrees warmer than it was during the pre-industrial period. It also showed that the temperature was about 10.5 degrees higher in the Arctic regions.
The study notes that the absence of permafrost has also been inferred from records of marine fossil deposits in northwest Alaska. The researchers showed that simulated winter and summer temperature and precipitation variables, which probably have the greatest impact on permafrost stability, are similar in the mid-Pliocene and the years 2100 and 2200. Its distribution in the warm period itself and associated climatic factors can improve our understanding of the extent, dynamics and uncertainty of permafrost loss in a future warmer climate.
“Based on our findings, the future for near-surface permafrost in the Northern Hemisphere looks bleak,” Romanowski adds. He concluded that the continued phenomenon of global warming and the associated deterioration may cause changes in environmental conditions that humans have not yet witnessed, which requires further highlighting the importance of their deterioration.