With 2014 still on track to be the warmest year on record (read about that here or here), a climate scientist at the University of Hawaii announced on November 14 that 2014 brought the highest global mean sea surface temperatures recorded since systematic measuring began. Axel Timmermann‘s study suggests that ocean temperatures exceeded even those of the record-breaking El Niño year of 1998. Timmermann is a climate scientist studying variability of the global climate system at the International Pacific Research Center. He reached his conclusions about exceedingly warm ocean temperatures in 2014 via an analysis of recent climate data.
From the years 2000 to 2013, the rise in global ocean surface temperatures paused, in spite of increasing greenhouse gas concentrations. This period – now sometimes referred to as the Global Warming Hiatus – has many people and scientists wondering. Explanations for the slowdown in warming have included the fact that Earth’s oceans and atmosphere are essentially one gigantic system, and that it’s possible large amounts of heat are being stored deep in the oceans.
Timmermann’s study – which deals with ocean warming on the surface – suggests that overall global warming might soon pick up the pace. Timmermann said:
The 2014 global ocean warming is mostly due to the North Pacific, which has warmed far beyond any recorded value and has shifted hurricane tracks, weakened trade winds and produced coral bleaching in the Hawaiian Islands.
He said his analysis showed that ocean surface temperatures started to rise unusually quickly in the extratropical North Pacific in January 2014. A few months later, in April and May, westerly winds pushed a huge amount of very warm water usually stored in the western Pacific along the equator to the eastern Pacific. This warm water has spread along the North American Pacific coast, releasing into the atmosphere enormous amounts of heat—heat that had been locked up in the western tropical Pacific for nearly a decade. He said:
Record-breaking greenhouse gas concentrations and anomalously weak North Pacific summer trade winds, which usually cool the ocean surface, have contributed further to the rise in sea surface temperatures. The warm temperatures now extend in a wide swath from just north of Papua New Guinea to the Gulf of Alaska.
Other studies are also beginning to show 2014 as an exceptionally warm year in terms of ocean surface warming (see the animation at the top of this post, for example). However, as Tom Yulsman comments in a November 17 story at Discover.com:
It’s way too soon to say whether this [ocean surface warming] is the start of a trend. But if it is, the ocean depths may be getting ready to give back some of the heat they’ve been banking.
And if so, things could be begin to get interesting.
Bottom line: Northern summer 2014 saw the highest global mean sea surface temperatures ever recorded since systematic measuring began, says Axel Timmermann, a climate scientists of University of Hawaii and the International Pacific Research Center. His analysis suggests that the 14-year-long pause in ocean warming might now have come to an end.