Ocean temperatures rising faster than previously thought

The world’s ocean temperatures are rising faster than previously believed as they absorb most of the world’s growing climate-changing emissions, scientists said on Thursday.

Ocean heat - recorded by thousands of floating robots - has been setting records repeatedly over the last decade, with 2018 expected to be the hottest year yet, displacing the 2017 record, according to a study by the Chinese Academy of Sciences.

That is driving sea level rise, as oceans warm and expand, and helping fuel more intense hurricanes and other extreme weather, the report said.

Heating up faster

The warming, measured since 1960, is faster than predicted by scientists in a 2013 Intergovernmental Panel on Climate Change report that looked at ocean warming, according to the study, published this week in the journal Science.

“It’s mainly driven by the accumulation of greenhouse gases such as carbon dioxide in the atmosphere due to human activities,” said Lijing Cheng, a lead author of the study from the Chinese Academy of Sciences.

The increasing rate of ocean warming “is simply a signature of increasing greenhouse gases in the atmosphere,” Cheng said.

Leading climate scientists said in October that the world has about 12 years left to shift the world away from still rising emission toward cleaner renewable energy systems, or risk facing some of the worst impacts of climate change.

Those include worsening water and food shortages, stronger storms, heatwaves and other extreme weather, and rising seas.

For the last 13 years, an ocean observing system called Argo has been used to monitor changes in ocean temperatures, Cheng said, leading to more reliable data that is the basis for the new ocean heat records.

The system uses almost 4,000 drifting ocean robots that dive to a depth of 2,000 meters every few days, recording temperature and other indicators as they float back to the surface.

Through the data collected, scientists have documented increases in rainfall intensity and more powerful storms such as hurricanes Harvey in 2017 and Florence in 2018.