Back to Climate Change

Jon and I back in the office this morning, me after 10 hours door to door from Istanbul, and Jon 44 hours from Adelaide!!

Checking emails and a very interesting one from Prof. Keith Atkinson, former Director of Camborne School of Mines:

Following our lunch, you may care to place this contribution on your blog and I'll watch for the brickbats!

I read the climate debate with interest and tend to agree with those who have taken your South African contributer to task. I thought you gave a balanced set of answers but reading his responses I can see that Galileo was right -"...we all tend to see what we expect to find". Regarding Ian Plimer, I first came across him when I was writing "Ore Deposit Geology" with Richard Edwards and therefore when I saw his article "Climate Change, a geologist's view" in Materials World, March 2009, I wrote to him as I thought his was an interesting view on the subject. He replied that his book, which you cite, had become a best seller in Australia and he was touring the country on book signings – not normally associated with academic authors! I have yet to read his book so cannot comment on the veracity of its findings, but I am struck by the emphasis that some of your contributors place on peer review. I agree that peer review is the best we have but what concerns me is peer review cannot always assess the original data. Remember the falsified Indian fossils saga? Furthermore I wonder how many reviewers check/rework the results and, of course, unless you have access to the programs and the models into which the data are fed you have no control over the predictions. Like you, I have experience of models produced by well recognized people which, when examined in detail, i.e. line by line, had some fundamental errors with far reaching, and erroneous, consequences. Have we all forgotten the Club of Rome and the Limits to Growth debates of the late 60's early 70's and the dire predictions for global mineral resources based on "models"? For those who have, we shouldn't have any mercury, tin etc by now!

Having got that off my chest I'd just like to make some observations based on geological data. Global temperatures have varied, often dramatically and over short time frames, throughout Geological Time. We could, of course, talk of the climate in "Britain" during the Cretaceous, or Triassic, as being much hotter than today but really that would have little bearing on today's position. Therefore we can look at the Holocene, and perhaps just the last 10,000 years and the Flandrian Transgression. As you know, the last major Glaciation ended about that time and sea level, globally, was over 100 metres below Present Day. This means that over the last 10,000 years sea level globally has been rising by an average of 1metre per hundred years (10mm p.a.). This, I believe, is equivalent to the most severe of the current climate model predictions for the next hundred years. Coming more up to date, the longest tidal gauge records for Europe suggest a small, but steady, rise since records began (c1800), with an acceleration over the last half century to about 2mm per year. For comparison, it has been calculated that around 8,000 years Before Present some 18 trillion metric tonnes per annum of glacially derived water was being added to the oceans and the global sea level was rising by about 50 mm per year. We have to talk of global because, with isostatic adjustment due to offloading ice, some land was rising and sea level in those areas was falling relatively. About 7,500 years ago the Climatic Optimum occurred when global temperatures may have been as much as 4degrees C higher than today. There is plenty of published work containing figures for specific areas. For example if we consider the North Sea between 8000 and 3000BP sea level rose from 55metres below present to 6 metres below present (therefore from 3000BP to today the average rise has been 2mm p.a.- the accelerated rate quoted above ).

What does all this tell us? Very significant global temperature variations, with concomitant sea level rises, have been occurring long before humans tramped the Earth and also while they have tramped the Earth but before they used massive amounts of fossil fuel sources (Oil, Coal) to contribute Carbon Dioxide to the atmosphere. Without going into the debate over the universality and accuracy of the temperature readings which you mention, as global temperatures are rising the big question - which I think you have already posed - is to what extent is man contributing? There is plenty of evidence to show it has happened in the past without "help" from man. In any scientific experiment you'd want a "control", unfortunately in this debate there isn't one, i.e. would this temperature rise (and sea level rise) have occurred anyway? This is where you need to examine the models very carefully - how do you establish the base level? how do you calculate the 'normal' annual effect (ie without man's influence), are there any missing variables, etc etc?

Finally, if we look at glacial/interglacial precedents, based on Milankovitch Cycles and previous interglacial stages, the Earth should be going towards another Ice Age, after the Climatic Optimum quoted above (you make reference to this in one of your comments to your South African contributor) so if man is having a marked effect what we may be seeing is a delay imposed on the next Ice Age!!

I think you have chosen a great topic for your future Conference let us hope that there are people there who can provide stimulating papers whatever their stance.

Incidentally, you may remember that in 1997 in conjunction with the University of Plymouth and the Plymouth Marine Laboratory I tried to establish a Centre for Climate Impact Forecasting (CCLIF) in the South West of England to help Insurance Companies, Banks etc understand the likely effects of Climate Change – and we failed to get funding support. How times have changed!!

All the best to you and Barbara and everyone associated with Minerals Engineering International.