Our oceans are heating up, and according to new research published in Science, they are doing so at an even faster rate than we anticipated. 2018 is likely to be the hottest year for the oceans on record, something highlighted by last year’s extreme weather events such as Hurricanes Michael and Florence.   

Ocean warming has devastating impacts across the globe. As the authors note in their paper, it leads to “increases in rainfall intensity, rising sea levels, the destruction of coral reefs, declining ocean oxygen levels, and declines in ice sheets; glaciers; and ice caps in the polar regions.”

The international team analyzed a number of new studies assessing ocean temperatures to conclude that ocean warming is “stronger” than predicted by previous research. The studies accounted for the fact that older assessments of ocean temperature relied on less accurate methods than we have today. Now we have a system called Argo, a fleet of 4,000 floating robots that can dive as deep as 2,000 meters (6,500 feet) below the sea’s surface.

The researchers found that ocean warming trends match predictions from leading climate change models and that this warming is happening at a pace 40 percent faster than what the United Nations estimated five years ago. What’s more, the team found that this warming is accelerating.

"If you want to see where global warming is happening, look in our oceans," said Zeke Hausfather, a graduate student in the Energy and Resources Group at the University of California, Berkeley, and co-author of the paper. "Ocean heating is a very important indicator of climate change, and we have robust evidence that it is warming more rapidly than we thought."

The temperature of the oceans acts as a very good marker for climate change as a whole because 93 percent of excess energy from the Sun trapped by greenhouse gases is found in the seas. This means that “the ocean is saving us from massive warming right now,” Malin L. Pinksy of Rutgers University told the New York Times.

But as the oceans get hotter, us land-dwellers will suffer the consequences – melting ice and thermal expansion will cause sea levels to rise by around 30 centimeters (12 inches) by 2100, flooding coastal areas. Extreme storms like hurricanes will also get worse, costing billions in damage. What’s more, the fish many people rely on for food and income will decline, or move into new areas, driving conflict between countries.    

So what can we do? To minimize warming we need to stick to the goal of no more than 1.5°C (2.7°F) warming set out by the Paris Climate Accord, by dramatically cutting down our greenhouse gas emissions.

“I think there’s some reason for confidence that we’ll avoid the worst-case outcomes,” Hausfather told the New York Times, “even if we’re not on track for the outcomes we want.”