Of the heat taken up by the world's oceans since 1865, nearly half has been absorbed in just the past two decades.

Peter Gleckler at the Lawrence Livermore National Laboratory in California and his colleagues examined data on ocean temperatures from ship-based measurements dating back to the mid-nineteenth century, and from a near-global network of floating sensors deployed since 2004. They found that most of the heat has accumulated in the upper layer of oceans.

But the data, and model simulations of the full depth of the ocean, suggest that more than one-third of the heat is stored below 700 metres, and this amount is rapidly increasing as Earth's climate warms.

Nature Clim. Change http://dx.doi.org/10.1038/nclimate2915 (2016)