- Written by Roy Turnbull
- Category: Debates
- Published: 13 March 2014
Sir – Your correspondent Ian Miller, (Letters, 27 February), repeats some of the many misleading or false statements put about by those determined to deny the overwhelming scientific evidence for human-induced global warming.
He starts by asserting that “the Antarctic is cooling”. That is not correct. The Antarctic Peninsular is warming rapidly (nearly 3C so far); Western Antarctica is warming at about 0.1C/decade (Steig et al, Nature, 2009) and the vast East Antarctic has experienced slight cooling in places and warming elsewhere. The overall trend is one of slight warming.
Mr Miller continues by misnaming the Intergovernmental (not International) Panel on Climate Change (IPCC) and wrongly attributes to it responsibility both for global temperature records and “computer models”, when the IPCC has no research function and merely collates and reports the findings of others.
Mr Miller also belittles the (correct) average global temperature increase thus far (0.8C).
But projections from the IPCC warn that such temperatures could rise almost a further 5C by the end of this century if we continue with the unrestricted burning of fossil fuels.
For comparison, average global temperatures during the depth of the last glaciation, when Strathspey was buried in several thousand feet of ice, were just 5C cooler than at present. A rise of 5C would be catastrophic.
Mr Miller is also misinformed in claiming that “World temperatures have not risen in line with ... computer models and have remained broadly flat”.
Firstly, there is no statistically significant evidence that the long-term trend of rising global temperatures experienced since the mid-1970s has changed. Secondly, unpredictable factors like solar variations, volcanic eruptions and El Nino/ La Nina episodes are well able to explain short term variations in surface temperatures. Thirdly, over 90 per cent of the extra heat caused by the increase in greenhouse gases is absorbed in the oceans, which exhibit continued warming.
Mr Miller is also confused about the terms “global warming” and “climate change”. The former refers to the increase in heat in the atmosphere/ land surface/oceans, whereas the latter refers to the corresponding change in climate.
If Mr Miller thinks the term climate change is new, he might ponder the meaning of CC in the IPCC, founded in 1988.
Mr Miller is also incorrect to claim that human actions cannot affect the jet stream, alterations in which are thought to be responsible for the UK’s recent extreme weather events.
The jet stream results from the temperature gradient between the Arctic and the tropics. Human caused warming of the Arctic has reduced this gradient and the unusual behaviour of the jet stream is thought to be the result.
Human-induced global warming is real, is continuing and is potentially very dangerous. No amount of confused denial can alter those facts.
Roy Turnbull, Torniscar, Nethy Bridge.