In the past, the Earth found examples of a sharp acceleration of global warming

In the past, the Earth found examples of a sharp acceleration of global warming
In the past, the Earth found examples of a sharp acceleration of global warming
Anonim

Paleoclimatologists have discovered several examples of how the rise in average temperatures has already led to a sharp acceleration in global warming and further warming of the Earth's climate. The results of their research were published in the scientific journal Science Advances.

"The northern polar cap may disappear in the coming decades and centuries. Our observations and calculations show that this will make the planet's climate much more vulnerable to extremely long episodes of sharp temperature rises, the analogs of which we found in the recent geological past of the Earth," said one of the authors research, Research Fellow at the Massachusetts Institute of Technology Konstantin Arnscheidt.

Arnscheidt, along with colleague Daniel Rothman, became interested in how episodes of sharp warming and cooling of the climate that have occurred on Earth since the extinction of the dinosaurs influenced temperature fluctuations in subsequent eras. These estimates are critical to understanding how current global warming will affect the planet's climate in the long term.

To obtain such information, paleoclimatologists collected samples of sedimentary rocks that accumulated at the bottom of the world's oceans in the past several tens of millions of years, and measured the proportion of carbon and oxygen isotopes in their different layers. This allowed scientists to determine at what temperature and salinity these deposits formed.

After analyzing these data, the scientists determined how much the temperatures increased or decreased after each episode of a sharp cooling or warming of the climate, and compared these data with each other. This allowed scientists to assess how actively the Earth reacted to abrupt climate changes in different geological eras.

“Previously, our colleagues analyzed only individual sharp fluctuations in climate, during which temperatures rose or fell by several degrees Celsius. Instead, we studied all statistics as a whole and analyzed all climate fluctuations,” explained Arnscheidt.

This analysis unexpectedly indicated that sharp decreases and increases in temperature did not occur with equal frequency in the epochs prior to the Pliocene, one of the relatively recent geological eras, which ended 2.58 million years ago. At this time, the planet's climate changed dramatically, as a result of which the last ice age began, which continues to this day.

As scientists have found, in previous eras, rapid climate warming occurred much more often than cold snaps. This indicates that initially high average annual temperatures or past episodes of their rise markedly increased the likelihood of additional bursts of global warming. This was not typical for cold snaps.

With what these accelerations of global warming were connected, scientists cannot yet say. However, they suggest that they were provoked by changes in the nature of the Earth's orbit and various biological processes, for example, the decomposition of organic matter in thawed permafrost, which provoked previous episodes of temperature increases.

Something like this, scientists suggest, could happen as a result of current global warming, which could destroy the polar caps and return average temperatures on Earth to those levels that were observed on the planet in the pre-Pliocene era. This will make the planet extremely vulnerable to subsequent global warming, paleoclimatologists summed up.

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