NASA's Clouds and the Earth's Radiant Energy System (CERES) suite of satellite sensors which measure how much energy leaves Earth, and compared those levels to data collected by ocean floats from around the world called Argo.
These floats are able to measure and estimate the rate at which the world’s oceans are heating up, according to NASA. "The two very independent ways of looking at changes in Earth's energy imbalance are in really, really good agreement, and they're both showing this very large trend, which gives us a lot of confidence that what we're seeing is a real phenomenon and not just an instrumental artifact, " said Norman Loeb, lead author for the study and principal investigator for CERES at NASA's Langley Research Center in.