That increase - of over 40%, with most since 1980 - traps heat in the Earth’s system, warming the entire planet. But measuring the ocean temperature is not straightforward. Hence we can now map the ocean heat content quite well. Putting data from these various sensors together has been a struggle and has been a major impediment to an accurate quantification of the ocean’s temperature history. One main outcome of the study is that it shows we are warming about 13% faster than we previously thought.

Source: The Guardian March 10, 2017 19:00 UTC