The Earth's ice sheets are much more vulnerable to rising atmospheric carbon dioxide (CO2) than we think, according to a new study by researchers from the University of Massachusetts Amherst. The study reconstructed the climate of Antarctica during the last period where CO2 levels were comparable to what they will be in approximately 30 years and, in combination with findings from a companion paper on sediment core findings, predicted how the continent's ice sheets would respond. The results showed that the Antarctic ice sheets may experience large changes at even lower levels of carbon dioxide exposure than what was suggested in previous studies.
The model created in the study represents the conditions similar to those experienced during the early to mid-Miocene, which scientists believe was the last time that atmospheric CO2 levels were slightly higher, 500 parts per million (ppm), than the 400 ppm level reached last year. Furthermore, global average temperatures were approximately three to four degrees Celsius higher than the average seen today.
Despite the findings, the team assures that the melting Antarctic ice sheets will not raise global sea levels immediately.
"The ice sheets will take hundreds of years to respond, so although CO2 may be at the same level as during the Miocene in the next 30 years, it doesn't mean that they will melt in 30 years," Edward Gasson, who participated in the research, said in a press release.
Nevertheless, understanding how these Antarctic ice sheets will respond to warming is a huge goal for climate scientists and will help us take preventative measures in order to minimize the detrimental effects of the process.
"We know that the Antarctic ice sheet will eventually melt if we burn all known fossil fuel reserves, raising sea levels by over 100 feet. What these two studies show is that the Antarctic ice sheet is also vulnerable to much lower levels of carbon dioxide than we thought possible before," he said.
The findings were published in the Jan. 21 issue of the Proceedings of the National Academy of Sciences.
