The global warming “pause” which some climate sceptics have taken as evidence that climate change is a myth could in fact be explained by a dramatic increase in the amount of heat being taken out of the atmosphere by the Pacific Ocean, a study has found
The easterly trade winds of the Pacific Ocean have increased significantly over the past two decades and as a result are blowing higher volumes of warm surface sea water and huge amounts of surface heat down to deeper depths of the ocean, scientists said.
An international team of researchers has calculated that the stronger trade winds blowing from South America to Australia have had the net effect of cooling surface temperatures by a global average of between 0.1C and 0.2C, which would be enough to account for the apparent hiatus in global average temperatures over the past 15 years.
The scientists warn however that the cooling capacity of the Pacific Ocean is not expected to continue much beyond 2020, when global surface temperatures are expected to start rising again rapidly as a result of increasing concentrations of man-made carbon dioxide.
“This hiatus could persist for much of the present decade if the trade winds continue, however rapid warming is expected to resume once the anomalous wind trends abate,” the scientists say in their the study published in the journal Nature Climate Change.
It is not the first time that the Pacific Ocean has been suggested as a possible explanation for the levelling off of global surface temperatures, which have failed to rise since the late 1990s as fast as computer models had predicted.
Previous studies have suggested that huge amounts of heat are being carried and stored at the colder depths of the Pacific. However, the stronger trade winds could now explain how the warmer surface water – which is lighter than the colder, denser water below – is forced deeper into the ocean.