14 DAY TRIAL // Bouts of global warming that saw Earth's temperatures rise significantly for periods lasting tens of thousands of years took place more often in our planet's distant past than researchers first calculated.
These periods, now called hyperthermals, tended to last for as much as 40,000 years, experts have discovered. After this period passed, global temperatures returned to normal until the next warming event, it was recently found.
The investigation that arrived at these conclusions was carried out by experts with the Scripps Institution of Oceanography at the University of California in San Diego (UCSD). Researchers here gathered a solid database of evidence to support their claims.
Information collected over several years indicates that the most likely culprit for the hyperthermals was the repeated release of massive amounts of carbon dioxide, that had been previously stored in the depths of the global ocean.
CO2 is one of the most potent greenhouse gases, and its actions are widely held responsible for the period of global warming we are currently entering. Unlike other hyperthermals, this one is not caused by the natural release of carbon, but by man-made emissions.
According to Scripps professor of geology Richard Norris, also the coauthor of the new study, most global warming events that occurred in the past raised average temperatures worldwide by 2 to 3 degrees Celsius (3.6 to 5.4° Fahrenheit), Daily Galaxy reports.
“These hyperthermals seem not to have been rare events, hence there are lots of ancient examples of global warming on a scale broadly like the expected future warming,” the team leader explains.
“We can use these events to examine the impact of global change on marine ecosystems, climate and ocean circulation,” Norris goes on to say. He adds that the events may have been separated by an average of 400,000 years between instances when they manifested themselves.
“In 100 to 300 years, we could produce a signal on Earth that takes tens of thousands of years to equilibrate, judging from the geologic record,” the Scripps investigator explains.
At this point, estimates show that, if our planet warms by 2 degrees Celsius, then the ice caps at the poles and atop Greenland will melt, causing devastating floods, and rising sea levels by several meters.