The Earth’s oceans are getting warmer. We knew that already, but new research says that it’s happening way faster than we thought. Thanks to connected sensors which bob through the ocean, surfacing to beam their data up to satellites, we have collected great ocean data in recent years. But these sensors were only deployed from 2005 onwards, which means that good historical data is harder to come by. Now, thanks to new research published in Science Advances, old data has been massaged to make it more accurate. The downside is that the data now shows that the oceans are warming 13% faster than previously thought.
The temperature of the oceans is, says the study, the best way to assess the historical patterns of global warming. The problem is that the measurements between 1960 and 2005 were taken by primitive equipment that was placed more for convenience than for comprehensive coverage. These bathythermographs had to be manually lowered and raised on a wire, so measurements took place around major shipping lanes, and mostly in the northern hemisphere.
Writing in the Guardian, study co-author John Abraham details the process his team used to fix those historical readings. First, they corrected for known errors in the measurements, then they extrapolated the results to apply to larger areas around the sensors. Then they compared their corrected data to computer models of the same places, and to data collected from better sources, and mashed the whole lot together.
The newly-cleaned data now goes back to the late 1950s, and shows that not only are the oceans warming around 13% faster than previously thought, but the rate of the warming has also accelerated: Today, the oceans are warming twice as fast as they were in 1960. Even worse, this warming has gotten deeper.
What does this all mean, other than that we got things a little wrong? One takeaway is that the climate is more sensitive to greenhouse gasses than previously thought, which in turn means that our models for future change are off. It’s likely that things will get worse faster than current estimates predict.
This new data also explains the recent disruptions in our weather. “The oceans are affecting weather and climate through more intense rains,” write the authors. “This process is a major reason why 2016 was the hottest year ever recorded at the Earth’s surface, beating out 2015 which was the previous record. Additionally, 2015 was a year with record hurricanes, heat waves, droughts, and wildfires around the world.”
These numbers make the urgency of the problem clear. They may be depressing reading, but better data means that we can better deal with what’s coming. Or we could if Trump hadn’t made denying climate change a job requirement for White House staff.