Thursday, August 28, 2008

Global warming sceptic letter

I got this into the Chew valley Gazette today. This is the first time that I have responded to global warming sceptics, because most of them are intractable, and at least one that I know is a conspiracy theorist, but Peter Taylor is a worthy sparring partner. Here it is:

I would like to respond to Peter Taylor (letters, August 21st), whom I remember well as a colleague in the battle against the dumping of nuclear waste at sea.

He says that the science of climate change is not as well established as people think. The opposite is true. While 60% of ordinary people think there is some doubt about the science, there is consensus among climate scientists that man-made global warming is a very serious threat indeed.

Peter asserts that there is a downward trend in world temperatures in the last 10 years. This is not borne out by data from the Met Office Hadley Centre and other institutes, which shows a definite and serious rise over the last 100 years. There was indeed a spike in 1998 that was higher than 2008, but in looking at global events, it is important to take the widest possible view, rather than taking one lone statistic. The Goddard Institute of Space studies say that the eight warmest years in the GISS record have all occurred since 1998, and the 14 warmest years in the record have all occurred since 1990.

Peter says that the Arctic is freezing again. I think he is referring to a record growth of the ice last December, but this is in the context of a record shrinking of the ice in the years previously, which has led to the opening up of the fabled North West Passage for the first time in history. The area of re-frozen ice was still less than the average for the last 25 years, and the rapid growth was due to the simple fact that it had room to grow.

Antarctica is melting at the edges, with huge cracks appearing in the old ice shelf. There is a pattern of warmer seas at the edge of Antarctica and colder trends at the South Pole itself. A possible explanation for this is that the warmer seas have produced more cloud and snowfall, leading to colder temperatures at the south pole.

Peter agrees that climate change is indeed happening, but puts it down to a natural variation in the output of the sun. The Royal Society, which represents the best in British scientists, says “While there is evidence of a link between solar activity and some of the warming in the early 20th Century, measurements from satellites show that there has been very little change in underlying solar activity in the last 30 years there is even evidence of a detectable decline and so this cannot account for the recent rises we have seen in global temperatures”.

We are agreed that the jet stream has changed its position. Scientists at the Carnegie Institution’s Department of Global Ecology report that “the Earth’s jet streams, the high-altitude bands of fast winds that strongly influence the paths of storms and other weather systems, are shifting—possibly in response to global warming… over a 23-year span from 1979 to 2001 the jet streams in both hemispheres have risen in altitude and shifted toward the poles. The jet stream in the northern hemisphere has also weakened. These changes fit the predictions of global warming models and have implications for the frequency and intensity of future storms, including hurricanes.

We have to accept that the global climate is a highly complex system, and the changes we are producing are still highly unpredictable. Global Warming misleadingly suggests balmy weather, but the science suggests that the word for it should be “perturbation” of weather patterns. We cannot deduce much from any one single piece of data. One swallow does not make a summer, and two wet summers “prove” neither global warming nor global cooling: we need to view the system as a whole, and viewed in that way, the many major weather events that are happening right now that are consistent with global warming.

I sincerely wish that Peter Taylor was right, so that we could all sit back and make carry on as usual. But even if he was right about global warming, we could still not do this, because of the mismatch between supply and demand for oil.

Look at it this way: if we drop the shackles of our addiction to oil and shift to the free energy income from the sun, and it turns out that Peter is right, we will still be better off, because oil prices are going to continue to rise. If on the other hand we carry on with our oil addiction, and it turns our that Peter is wrong, we will not only get even more of the floods, droughts, and extreme weather events that science predicts, but also we will ruin our economy, because oil price rises will drive inflation into the skies.

Dr Richard Lawson
Green Party Candidate for Euro-elections 2009
(A fuller version of this response, with references will be on my website

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