Reply to Summerhayes Rec'd & Pub'd 19 April)
Sir, This should be seen by all Fellows!
http://wattsupwiththat.com/2011/02/12/david-archibald-on-climate-and-energy-security/#more-33809
Colin Summerhayes comments:
I have no doubt that there are a lot of global warming nay-sayers out there; some of them are among our Fellows. In due course I hope that we can persuade doubters by sound scientific argument to accept that global warming is indeed taking place and that it is caused by our activities. In that context I take heart from the recent TV programme "
Storyville meets the climate sceptics" at 10pm on Monday Jan 31, in which arch-sceptic Lord Christopher Monckton agreed that the Earth is indeed warming, that CO2 is indeed increasing, and that increasing CO2 should warm the atmosphere. A key point he wanted to make was that he and his ilk thought that the climate sensitivity was low (i.e. a doubling of CO2 would lead to a rise of no more than 1 degree C), while others, like Jim Hansen of NASA, thought it would be high (3 deg C for a CO2 doubling). There seem to be a lot more climate scientists on Hansen's side than on Monckton's. Hansen has the virtue of basing his assessment not on climate models, which have too many faults for his liking, but on paleoclimate data - especially how the Earth warmed in relation to CO2 during the past 4 major interglacials. It is because he relates his arguments to these real world geological data that I am most inclined to go along with his thesis, which is elaborated upon on his web sites (www.giss.nasa.gov/; www.columbia.edu/~mhs119/) and in his book "Storms of my Grandchildren".
The blog referred to by DBQ is from David Archibald, a member of the Australian Climate Science Coalition, which argues against human-induced global warming. Mr Archibald lists his interests as climate, oil, and cancer. I was unable to find out from his web site what his scientific credentials are, and I note that he fails to cite most of the sources for his climate change slides in the blog, so it is difficult to judge what merit we should accord his arguments. Some of his own papers on climate change topics were published in Energy and Environment, the peer-review process of which has been criticised as facilitating the publication of scientific papers by global warming sceptics.
Mr Archibald’s blog and his web site suggest that he believes that much of recent climate change is largely due to the sun, and has little to do with CO2 or humans. He is right to point out that there can be periods of sunspot minima that might cool the Earth temporarily, as happened in the Maunder Minimum of 1645-1715, but that is not something new to the climate science community. There have been no or few sunspots for quite a while, which is interpreted by some to indicate that we may be headed for a sunspot minimum that would cool the Earth slightly. But even if we are, that does not mean that growing atmospheric CO2 may not counteract the effects. Anyway, careful analyses of the competing theories (sun versus CO2), shows that solar activity has been largely flat (apart from sunspot wiggles) since the recent warming trend began in around 1970, which puts a dent in Mr Archibald’s hypothesis. For some discussion of the arguments see Hansen’s book. Hansen is a hard man to refute, supported as he is by masses of data and experience, though not everyone likes the way in which he describes naysayers, nor his stand on civil disobedience in relation to the construction of power stations without carbon capture. The difference between the two men, as I see it, is that one is testing scientific hypotheses and generating data and making it public for all to see, while the other is expressing opinions about the science.
Great care needs to be taken in navigating blog sites away from the peer-reviewed scientific literature on climate change. There is always a danger that data may have been cherry-picked to make a point; that pieces of graphs may have been selected so as to hide inconvenient overall trends that might tell a different story; and that short term variation is considered more important than long term trends. Of course I am also aware that there can be dangers in the peer-reviewed literature (i.e. the UEA story). This is a reminder to all of us of the wisdom in the latin tag - caveat emptor.
Reply to Dr Summerhayes
How amusing to be included among FGS `naysayers` by Dr Summerhayes (CS)! Had he seen the message I sent to the Editor, Ted Nield ("let me make it plain that I am neither a “warmer” (AGW) nor a “denier”") after recommending the blog in question I doubt such a gratuitous epithet would have been used. My position is clear enough in evidence to the House of Commons Committee on Science and Technology (Scientific Advice on Climate Change, Third Report 28 February 2001), and in the geological conservation magazine Earth Heritage (Jan 2000).
Surely the debate is about whether it is possible to distinguish between natural climate variability and that caused by people. So how can there be consensus about the future? The only real consensus is:
- that since the Little Ice Age and Industrial Revolution the average global temperature has probably risen by about 0.6 degrees Celsius and carbon dioxide has increased by about 30% over the same period;
- there is good evidence that anthropogenic activities have been responsible the increase in carbon dioxide although natural processes may also have contributed;
- a doubling of the carbon dioxide concentration would increase the radiative forcing of the Earth, the difference between incoming and outgoing radiation, by about 2%. Is that a cause for alarm? Politicians think so. But the rise in temperature has not tracked that of carbon dioxide to show a direct causal connection. Internal variability and natural cycles in the climate system with their complex non-linear feed-backs are far from being understood. Is it credible that enough comprehensive data of high quality, especially on land, exist for computer models to predict the future? Instead are geological analogues useful?
Some of those suggested, such as Pliocene warmth (5.4-3 Ma) or that of the PETM (55 Ma) enjoyed physical boundary conditions far removed from the Brunhes Chron where no two interglacials were alike and all ended soon after their carbon dioxide concentrations peaked. The leading authority on the PETM has said it `is not an ideal analog for future anthropogenic warming` (Zachos, EGU abs 2011). In any event, it coincided with a massive release of greenhouse gases from the Tertiary Igneous Province of the North Atlantic (Svensen et al 2010, JGS, 167; Zeebe et al Nature Geo. 2009).
There is no question but that the entire range of evidence and opinion is not in any open and accessible domain. On blogs (see CS): there are, of course, blogs and blogs. But many draw rapid attention to newly published refereed articles in, for example, Geophysical Research Letters and the Bulletin of the American Meteorological Society (Distinguishing the Roles of Natural and Anthropogenically Forced Decadal Climate Variability, 92, 141-156 Feb 2011 2011); as well as to NOAA satellite measurements since 1979. Some ask pertinent questions, such as: is carbon-dioxide, essential for plant growth, a dangerous toxin destroying the planet; and is it responsible for all `disasters` otherwise considered as episodic natural occurrences? Care must be taken not to deny access of `nay-saying` information to the media as one politician once famously recommended. The most recent reasoned analysis of the relationship between climate, energy and economics is The really inconvenient truth (March 2011) by former Cabinet Secretary Lord Turnbull1. Who can deny the value of such erudite and thoughtful commentaries? It would be interesting to read a similarly soberly written piece from an 'ay-sayer` to see where the differences lie. They think that this has already been done and proclaim 'the science is settled'.
But what would James Clerk Maxwell, Albert Einstein, Richard Feynman and Karl Popper have made of this? Would they have laughed or cried?
David Bowen, 14 April, 2011.
http://www.thegwpf.org/opinion-pros-a-cons/2711-lord-turnbull-the-really-inconvenient-truth.html