text: Focussing on the recent period in more detail, the onset of the current pause coincides with a maximum in upper ocean heat uptake around 2002, and may reflect a recovery both from Mount Pinatubo and from the record 1997/98 El Nio. A recent study (Guemas et al, 2013) shows that, in 2002, the upper ocean below the mixed layer took up heat, while the mixed layer and sea surface temperature did not warm. The onset of the pause may therefore have been caused by ocean processes, predominantly in the tropical Pacific, in which energy trapped by greenhouse gases was buried below the surface of the ocean.