Scientists have claimed that a huge carbon "burp" from deep ocean kick-started global warming at end of the last Ice Age some 18,000 years ago.
According to the scientists, the carbon dioxide was actually locked away in the deep ocean "repository" and as the Earth warmed, it was released into the atmosphere causing the global warming and ending the last Ice Age.
It is believed that carbon dioxide was dissolved in the waters of the deep ocean during ice ages, and that pulses or "burps" of carbon dioxide from the deep Southern Ocean helped trigger a global thaw every 100,000 years or so, 'The Daily Telegraph' reported.
The size of these pulses was roughly equivalent to the change in carbon dioxide experienced since the start of the industrial revolution.
Throughout the past two million years, the Earth has alternated between ice ages and warmer climates. These changes are mainly driven by alterations in the Earth's orbit around the sun, but they have been accelerated by changes on the planet's surface, say the scientists.
One of those is thought to be the huge storage and then release of carbon dioxide by the oceans.
"If enough of the deep ocean behaved in the same way, this could help to explain how ocean mixing processes lock up more carbon dioxide during glacial periods," Dr Luke Skinner of the University of Cambridge was quoted as saying.
The findings have been published in the latest edition of the 'Science' journal.