How hot will the earth be after 140 years?
The US media said that the rate of carbon dioxide emissions into the atmosphere is now about 10 times that of the last major period of global warming. In fact, when the last level of carbon dioxide emissions was so high, the Arctic became home to palm trees and crocodiles.
According to a report by the US Newsweek website on February 25, in a study published in the Journal of Paleo-oceanography and Paleoclimatology of the American Geophysical Union, researchers observed the current rate of carbon dioxide production. It was compared with the case of the Eocene Thermal Extreme (PETM) period of approximately 56 million years ago.
During PETM, a large amount of carbon dioxide is emitted into the atmosphere, causing global temperatures to rise from 5 degrees Celsius to 8 degrees Celsius. Global temperatures reached about 23 degrees Celsius during peak times - about 7 degrees Celsius higher than current. The current climate change model shows that unless we substantially reduce the amount of greenhouse gases injected into the atmosphere, global temperatures will rise by about 4 degrees Celsius.
The report said that the reason for the high carbon dioxide emissions during the PETM period is unclear. However, scientists estimate that between 3,000 and 20,000 years, carbon emissions have accumulated between 3,000 and 700 billion tons.
During PETM, the poles are essentially free of ice, and the influx of carbon dioxide and the soaring global temperatures may lead to widespread extinction of the marine environment. It also causes terrestrial animals to become smaller and migrate north to a lower temperature climate.
Scientists often use PETM as a model for what might happen in the future of the Earth's climate.
In the latest study, researchers invented a method to compare current CO2 emissions with CO2 emissions during PETM on the same time scale. The results of the study show that the current carbon dioxide emissions are 10 times the emissions during PETM. Researchers estimate that if carbon dioxide emissions follow the current trajectory, we may be able to reach carbon dioxide levels never reached since PETM in 140 years and 300 billion tons of carbon dioxide by 2159. By 2278, carbon dioxide emissions will exceed 700 billion tons.
The first author of the study, Philip Gingerrich of the University of Michigan, said in a statement: "For me, this really made me realize how fast and how much our humans produce carbon." He said: "You and I will not live in 2159, but it only takes four generations."
Lavida de Santis, a paleontologist at Vanderbilt University who was not involved in the study, said in a statement: "We are able to quickly reach the warming level of PETM in the next few hundred years. The truth is terrible," he said. "Not only is 100 years later, it will take a long time for carbon dioxide to return to the earth's crust. This is not a short-term event."
As part of the 2015 Paris Agreement, countries around the world agreed to limit greenhouse gas emissions with a view to keeping climate warming below 1.5 degrees Celsius by the end of the century. However, a report released by the Intergovernmental Panel on Climate Change last October showed that countries are unlikely to achieve these goals.
A report last December also found that global carbon emissions reached an all-time high in 2018, with an estimated annual increase of 2.7%.