British scientists reported that they were able to find out exactly how the Earth got rid of a short, but strong global warming that occurred at the time of the dinosaurs. Mass dumping of rocks in the sea unleashed certain substances which were connected with carbon dioxide, causing him to drop the level of the world.
About 180 million years ago, the earth's temperature has jumped rapidly — by five degrees Celsius. The reason is the sudden release of large amounts of methane from the seabed. Methane — a greenhouse gas, although short-lived, however, when oxidized produces carbon dioxide, which may be retained in the atmosphere for a long time.
From this change in the composition of the atmosphere affected plants and animals. Scientists have found evidence of a mass extinction of marine organisms at the time, had destroyed 84% of bivalve molluscs. And then in about 150,000 years the Earth has returned to normal. As it happened — remained a mystery, but scientists from the Open University in Milton Keynes believed that found a possible answer. They collected data showed that as a result of warming, erosion of rocks on the surface of the earth accelerated sharply — by 400%. So intense was the process drag on global warming — through a chain of chemical reactions that consumed the excess carbon dioxide from the atmosphere.
The researchers found that intense erosion coincided with the warming and high content of carbon dioxide in the atmosphere. Erosion occurs under the action of rain. Although scientists have not found direct evidence of increased rainfall, they believe that at that time in the moisture there was no shortage.
Warm conditions causing "methane burp", would accelerate the erosion. This should lead to leaching of calcium and magnesium rocks and falling into the ocean. Calcium was connected with carbon dioxide and deposited in the form of calcium carbonate. This process of consumption of carbon dioxide can reduce the content of substances in the atmosphere worldwide. Once the level of carbon dioxide decreased, the temperature dropped.
The researchers hope that the study of this protective mechanism triggered in the past, will help determine what we can expect in the future — in fact at the bottom of the ocean are still a gas hydrates, which may at some point release the methane contained in them.
Battery News, 06-02-2004 10:12