Melting permafrost will play a major role in shaping Earth’s future. Recent research published in Nature Communications has established that alpine permafrost will melt much faster than arctic permafrost under current conditions. This melt would release carbon and other harmful greenhouse gases into the atmosphere.
According to the researchers, the future Earth could resemble the mid-Pliocene warm period from 3-3.3 million years ago. At the time, average air temperatures rarely dropped below freezing. Permanent ice had just started forming at about this time, both in the polar and mid-latitude alpine regions.
With these ice zones now melting at a rapid rate, the amount of greenhouse gas in the atmosphere is projected to grow. Today, permafrost across the world holds approximately 1,500 trillion grams of carbon. This is double the amount of carbon stored in the atmosphere. Meanwhile, alpine permafrost holds about 85 trillion grams of carbon. When this ice melts, it releases these huge amounts of carbon back into the atmosphere.
“Atmospheric carbon dioxide concentrations today are similar, or maybe even higher, than the mid-Pliocene because of the burning of fossil fuels, and so scientists point at that time period as an analog for our current and near-future climate,” said Carmala Garzone, paper co-author and dean of the University of Arizona College of Science. “We’re not feeling the full effects of the rise in atmospheric carbon dioxide yet because our Earth system takes time to adjust.”
Researchers studied lakebeds in the Tibetan Plateau lake to estimate what Earth looked like during the mid-Pliocene epoch. They collected carbonate from the bottom of lakes and used it to approximate temperatures during the Pliocene and Pleistocene periods. Atoms in the carbonate can help determine the temperature at which it formed.
The researchers warn that what we are seeing today is just the iceberg regarding climate change. Since Earth takes time to adjust, the researchers predict the planet will move toward a climate like that of the Pliocene period.
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