If you are sat in a cold bath and turn on the hot tap, what happens? The water close to your feet becomes unbearably hot and the water near the top half of your body doesn’t noticeably change temperature. Fundamentally, the same process happens in the oceans. The sea nearest to the equator heats up as it receives the highest amount of energy from the sun; the sea nearest to the poles generally loses heat. In the bath, you slosh the water about as it enters the tub to distribute the heat more evenly. In the oceans, currents perform the same job, helping to move heat from the equator to the poles and make higher latitudes more habitable. If, for some reason, the currents transporting heat to higher latitudes slowed, the effect would be similar to you not mixing your bath water. Your feet (the equator and tropics) would become hotter, and your body (the subtropics and poles) would become colder. This is exactly what scientists think they observed in 2009/2010 in the North Atlantic, and they think this may explain some of the freak weather that was observed during that period.
Since the final climate change episode of ‘Frozen Planet’ aired this week I have encountered three attempts to discredit the science: one statement1 by Nigel Lawson and two articles2, 3 by Chrisopher Booker (the first of which accuses the BBC of presenting a one-sided argument, when if anything they made too much of an effort to be balanced – not once did they blame humans for the changes observed). In what I am sure is a pure coincidence, all of these retorts were commissioned by The Global Warming Policy Foundation. This registered ‘charity’ is a think tank, funded by secret donors, that claims to be: