This was due to a combination of factors: a less active sun, higher levels of cooling aerosols from volcanoes and Asian factories, and increased heat uptake by the oceans. (newscientist.com)
That the slowdown in surface warming has been concentrated in the ocean - surface (and shallow - ocean) temperatures has led a number of scientists (including the Met Office) to posit that the pause in ocean surface warming may be driven in part by increased heat uptake in the deep ocean. (yaleclimateconnections.org)
Similarly, Matthew England and colleagues reproduced observed temperature trends by providing the model with the pronounced and unprecedented strengthening in Pacific trade winds over the past two decades — and the winds in turn lead to increased heat uptake by the oceans. (shapingtomorrowsworld.org)