Atlantic Ocean soaks up heat to slow global warming, scientists believe

The Atlantic Ocean is masking global warming this century by soaking up vast amounts of heat from the atmosphere in a shift likely to reverse from around 2030 and spur fast temperature rises, scientists say.

The theory is the latest explanation for a slowdown in the pace of warming at the earth's surface since about 1998 that has puzzled science because it conflicts with rising greenhouse gas emissions, especially from emerging economies led by China and India.

"We're pointing to the Atlantic as the driver of the hiatus," said Ka-kit Tung, of the University of Washington in Seattle and a co-author of the study published in the journal Science.

The study said an Atlantic current carrying water north from the tropics sped up this century and sucked more warm surface waters down to 1,500 metres, part of a natural shift for the ocean that typically lasts about three decades.

It said a return to a warmer period, releasing more heat stored in the ocean, was likely from 2030. When it does, "another episode of accelerated global warming should ensue", the authors wrote.

Almost 200 governments aim to agree on a deal to combat climate change at a summit in Paris late next year, and the hiatus has heartened sceptics who doubt there is an urgent need for an immensely expensive shift from fossil fuels to renewable energies.