The oceans are warming up faster than we thought. While this is bad news for the planet, it’s good news for climate change scientists who have — for the last two decades — puzzled over warming trends in ocean surface temperatures for nearly 20 years.

According to a big chunk of ocean surface temperature recorded by boat, the oceans were not warming nearly as quickly as the rest of the planet. This mystified scientists, but climate change skeptics used it as surefire, "scientific" proof that climate change either wasn’t as bad as scientists thought, or it didn’t exist, at all. 

Now, a new study, published in Science Advances, has confirmed what NOAA first discovered in 2015 — the oceans are indeed warming, and faster than we thought. So why the change? It comes down to what every scientist knows too well — analyzing data collected by different methods, and at different times, is a tricky business because some methods of collecting ocean surface temperatures are more accurate than others.

The new study confirmed that data collected by boats were slightly different than data collected by buoys and satellites. So, when scientists combined all of the data, it skewed the results. To identify what’s really happening, the new study analyzed numerous data sets individually — instead of combing them all together.

They discovered that oceans have been warming about 70% more per decade for the last 19 years than previously thought.