Climate sceptics invariably produce one or more of three arguments, all of which are fallacious.
1. Argument. The Scientists are divided.
Answer. No, if ever they were they are not divided now in any significant sense. In 2003 Naomi Orestes examined every scientific paper she could find dealing with climate change, and out of over 500 found not a single one taking the position that climate change is not manmade. In 2011 The Skeptical Scientist, a journal dedicated to picking holes in consensously held theories, surveyed individual climate scientists and found 97% supported the consensus. Virtually every national scientific body in the world, the equivalents of the British Royal Society, has signed up to the view that the current global warming is manmade and a significant danger to the planet. There are nearly 200 of them. Every scientific body in America has done the same thing, even, in 2007, the American Association of Petroleum Scientists, who were understandably reluctant to do so. There is hardly a field of science in which there is the same degree of agreement as there now is in climate science.
2. Argument. Changes in climate are caused by the sun. Nobody doubts that the Medieval Warm Period and the cold Maunder Minimum of the seventeenth and eighteenth centuries were caused by changes in the sun’s relation to the earth. This explains the present warming.
Answer. It is true that changes in the sun’s relation to the earth does have severe effects on our climate. But the sceptical argument is a complete misunderstanding. The changes in the Medieval Warm Period and the Maunder Minimum were caused by sunspots, flares on the earth’s surface which can last for earthly centuries. When there are sunspots our temperature gets warmer, when there are not it cools quite dramatically, as it did in the seventeenth and eighteenth centuries. The crucial fact is that no sunspots have been observed in recent decades. The average global temperature should be significantly colder than it is, which is why in the nineteen seventies, before the full extent of manmade climate change was realised, scientists were predicting a mini ice age. Changes in the sun’s heat falling on earth have exactly the opposite significance from that put forward by the sceptics.
3. Argument. Everybody agrees that emissions of carbon have greatly increased since 1998. But average temperature has not. Thus there is no connection between the two.
Answer. To the layman temperature means the temperature of the air. You open your door in the morning and sniff the air and say ‘it’s colder today’. But to a scientist air temperature and sea temperature are inextricably mixed, because the sea absorbs warm air. Warm air is blown across the Pacific by trade winds until it meets cold air coming up from the Antarctic near Australia and sinks into the sea. In recent years we have been experiencing exceptionally strong trade winds which explains why there has been less warm air hanging around waiting
to be measured. If we take air temperature and sea temperature together, which is what we should do, then global temperatures have risen fully in line with carbon emissions.
Don’t be taken in.