The extra ocean heat is coming from the atmosphere, said Braddock Linsley, an oceanographer at Lamont-Doherty Earth Observatory at Columbia University and lead author of the study.
"Because the ocean is in contact with the atmosphere, there's heat exchange between the atmosphere and the surface ocean," he said. "It seems that about 90 percent of the heat that should be in the atmosphere right now with all that extra CO2 [humans have emitted since 1999] has gone into the ocean.
http://www.scientificamerican.com/article/pacific-current-change-slowed-global-warming/