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The weather and climate change are not the same thing

Repeat: the weather and climate change are not the same thing. The troubles of the <i>MV Akademik Shokalskiy</i> do not tell us anything about long-term trends in the Antartic.

The BBC Daily Politics conducting a poll in London.
The BBC Daily Politics conducting a poll in London on 10 January 2014.

One of The Armstrong and Miller Show’s better sketches opens with a couple sitting in their living room on a rainy day. The man tuts, gestures to the window, and asks: “Whatever happened to global warming, eh?”

“Stop!” a voice-over demands. “From 1 October, if you say, ‘Whatever happened to global warming, eh?’ whenever it’s a bit cold or wet, you could be cooling off – in jail.” It’s a simple gag about the kind of bore who doesn’t understand the difference between weather and climate.

The confusion between the two is sometimes deliberate and sometimes not. The wilfully ignorant came out in force recently, reacting smugly to the plight of the 74 passengers on board the MV Akademik Shokalskiy, a Russian research vessel chartered by the Australasian Antarctic Expedition (AAE) that has been stuck in ice since Christmas Day. On 2 January, 52 non-essential crew members were successfully evacuated from the ship.

It had been heading for Mawson Station in Mac Robertson Land, named after the Antarctic explorer Douglas Mawson. Between 1911 and 1914 he made some of the first accurate scientific measurements of the continent – including the size and location of its glaciers – and the AAE expedition intended to measure how its climate has changed over the past century. The expectation was that some of the glaciers will have partly melted, in line with other studies used as evidence for climate change.

It’s a bit awkward to get stuck in ice on an expedition to measure how much that ice is melting. It is especially awkward when those who conflate weather with climate get involved. “Leader of trapped team insists polar ice is melting,” cooed Fox News, while the Australian ran a gleeful editorial arguing that the AAE expedition “must accept the embarrassing failure of their mission shows how uncertain the science of climate change really is”.

Yet one localised incident does not disprove the vast body of evidence demonstrating that the world is heating up, decade by decade. This kind of propaganda trick is no different from a creationist using a missing link in the fossil record of a single species as “proof” that the entire structure of evolutionary theory is flawed.

First, the ice is melting, at both poles. At the North Pole, the long-term trend has been around a 3 per cent reduction in ice each decade since measurements began in the 1950s. At the South Pole, the picture is more confused: it looks as if the amount of sea ice is increasing, much to the delight of climate-change sceptics who ignore that land ice is simultaneously decreasing. Quite why there has been an increase in Antarctic sea ice is unclear but one hypothesis is that melting land ice is diluting the salty ocean, raising its freezing point. If this is true, it’s likely to be a short-term phenomenon.

Second, it’s summer now in the southern hemisphere, and the MV Akademik Shokalskiy wasn’t trapped by the sea freezing around it. Instead, ice that had broken off from the Mertz glacier was unexpectedly trapped close to shore by a large iceberg, blocking the ship’s route to Mawson Station.

If this was the fascist world of the Armstrong and Miller sketch, the reaction of some climate-change sceptics to the MV Akademik Shokalskiy’s troubles could attract a prison sentence. Alas, in the world as it is, we can resort only to rational debate.