Are the oceans warming up too?
Human activities have increased the concentration of greenhouse gases in the atmosphere and enhanced the greenhouse effect, resulting in the accumulation of extra heat on Earth. Most of the extra heat goes to the oceans. The warming is not restricted to the sea surface. The sign of warming is observed down to 2000 m below the surface of the oceans. A direct consequence of ocean warming is sea level rise. According to the Fifth Assessment Report of IPCC, thermal expansion of sea water contributed to a global average sea level rise of about 1.1 mm per year during 1993-2010.
Global sea surface temperature anomalies (relative to 1961-1990) from various datasets (Source: IPCC, 2013)