Human industrial activity burns fossil fuels which then release planet-warming greenhouse gases into the atmosphere thereby causing the Earth to warm. Most of this "extra" heat goes into the ocean (some 93.4% over the last few decades) and the rest goes into heating the land, global ice, and atmosphere (2.3%).
All these Earthly heat reservoirs are warming, resulting in the global-scale loss of land-based ice from mountain glaciers and the polar ice sheets, and the rise of global sea level. Indeed the rate of sea level rise, although complicated by a handful of factors, has risen at a much greater rate over the last two decades (the period of satellite-based observation) than it did during the rest of the 20th century.
Despite these observations clearly indicating ongoing heat accumulation by the Earth's climate system, climate science contrarians and some mainstream media have been hard out propagating the myth that global warming has paused. This, of course, relies on the time-honoured contrarian tradition of cherry picking - one of the five characteristics of scientific denial.
Surface air temperatures have recently warmed at a slightly slower rate partly due a temporary increase in tropical and mid-latitude wind strength which mixes more heat down into the ocean. Contrarians and some media outlets have misconstrued this slower warming of surface air temperatures for a pause in global warming. The ocean is by far the largest heat reservoir on Earth and the stronger ocean warming means, counterintuitively, that global warming has increased at a faster rate in recent times. Unsurprisingly, contrarians and like-minded media studiously avoid mentioning this highly relevant fact. Or if they do, a lot of hand-waving often ensues in an attempt to dismiss the inconvenient truth.
Josh Willis is an oceanographer at NASA JPL who has published a lot of peer-reviewed scientific research on the current warming, and rise, of the global oceans. In the NASA: Ask a Climate Scientist video below he gives his uniquely humorous take on the frequently asked question on whether there has been a pause in global warming. Like Josh says, when the world is still warming and global sea level is rising "like gangbusters", pawses are strictly for kitty cats and puppy dogs.
Posted by Rob Painting on Tuesday, 19 November, 2013
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