Thursday, March 25, 2010

MICHAEL MANN AND LEE KUMP: DIRE PREDICTIONS – UNDERSTANDING GLOBAL WARMING

The Reader’s Digest magazine used to publish what they referred to as “unexpurgated abridgements.” By this they meant that they had left in the exiting bits and cut out the boring bits. This book could be considered an “unexpurgated abridgement” of the IPCC 2004 Technical Assessment Report. A lot of the detailed science has been left out but the elevated temperatures and other symptoms associated with an attack of ‘dire era’ are given lurid prominence.

The book does give a clear and approachable synopsis of how our climate operates and how human activity can lead to changes. As an introduction to the science, the book is quite good. It is clearly written and has good supporting material. It also tackles some of the issues raised by sceptics.

In a recent double interview in Discover magazine with Judith Curry and Michael Mann, Judith Curry drew a nice distinction between ‘political sceptics’, who do not want climate change to be true, and ‘scientific sceptics’, whose opinions are based on the evidence. I would suggest that there is a third type of sceptic: the ‘bar-room’ sceptic, who’s not reticent about sharing his knowledge over the internet. You know the type “Why does the IPCC ignore the book ‘The incredible lightness of being’ by the Russian Milan Kovich which proves CATEGORICALLY that the recent so-called warming has all been due to fluctuations in the earth’s orbit?” Unfortunately the authors tend to engage with this level of sceptic rather than the scientific sceptics. The issues where there is real scientific debate, the ‘hockey-stick’ and the urban heat island effect are either ignored or glossed over. Instead they rebut claims that the increase in CO2 is due to natural fluctuations, which scientific sceptics generally accept, or raise the hoary chestnut of “In the 70s the scientists said we were in for global cooling so why should we believe them now?”

The way they tackle the cooling/warming issue says a lot about the authors’ scientific credibility. They present a pair of graphs (page 45 in my edition) which show that the northern hemisphere temperature fell from 1940 to 1970, which explained the then current belief in cooling, and then again increased. Like the rest of their graphs there is no reference to the source but as it starts in 1850, and only the CRU record started in that year, it is reasonable to assume that that was the source. Yet their graph is very different to the CRU one: they show temperatures rising from 1970 to the present by 1.8 °C but the CRU data shows a rise of less than half of that. Elsewhere (pages 20 and 88 in my edition) they show graphs of ‘past observed surface temperature changes’ with an almost constant rate of temperature rise and no sign of the 1940 to 1970 fall. This is very different to the above graph. Since the observed global temperature record shows similar variation to the northern hemisphere record that does not explain the anomaly. Once again without references it is difficult to be definitive but it is almost certainly the ‘modelled’ temperature increase which they have presented as ‘observed’. This gives the false impression that the temperature increases projected by the models follow on naturally from steadily rising observed temperatures.

The book is in fact heavy on dire predictions, based on model projections, but very light on evidence that the models were able to represent past changes accurately. For example, they talk of precipitation changes as being probably of ‘more importance than temperature changes’ but present not a shred of evidence of how well models simulated precipitation. At least the IPCC report does have a shred of evidence: a graph which occupies 1/8 of a page!

What is most frustrating is the fact that this biased, one-sided, presentation of the facts is counter-productive. I fully accept that people are in part responsible for the recent temperature increase. I fully accept that there are many reasons, one of which is CO2 emissions, for reducing fossil fuel consumption. I fully accept that climate projections should play a major role in how we plan for the future. Yet, largely because the IPCC and scientists chose to ignore Abraham Lincoln’s dictum and think that in this ‘information age’ they can ‘fool all of the people all of the time’, the number of climate change sceptics is currently growing.

To give a final example: in his book “Cool It” Bjorn Lomborg mentions the 35,000 people killed in a heat wave in Europe. He also mentions that many more people die of cold in winter and follows it with a nuanced discussion of age profiles and the difficult moral question of how you balance the deaths of old people and of children. In this book only the heat deaths are mentioned. If you are an intelligent, thoughtful, person which approach is most likely to help form your opinion?

I also noticed a typo on the back cover where the book is described as being a scientifically ‘based’ overview. And where, you might ask, is the typo? It’s the missing “i” of course?

Authors: Michael Mann and Lee Kump
Publisher: Dorling Kindersley, 2008
ISBN: 978-0-7566-3995-2

No comments:

Post a Comment