This article adopts the erroneous attitude that scientific matters are resolved by consensus. Consensus belongs to the social arena, among legal decisions and politics, not among science where demonstrable correctness is the key. Society would be in a significantly backward state without the break-throughs by scientists who opposed consensus.

Griffin has failed to produce any evidence for his claim that global warming is occurring now, nor the more important but implied claim that the warming is anthropogenic and that something can and should be done about it.

Indeed the steadily increasing level of atmospheric carbon dioxide but failure of recent temperatures to reach the 1998 peak suggests that the notion of carbon dioxide driving temperatures may be seriously flawed.

In the last few months the famous "hockey stick" graph of temperature has taken yet another beating, bringing those refutations to about 6 in recent years.

In recent weeks the notion of anthropogenic global warming has been disputed in the Dutch, Portuguese and Canadian media in reports which are long overdue.

This week we will see a rash of reports from the conference at the UK's Hadley Centre. It's a conference which will define a "dangerous level" of greenhouse gases to the British prime minister so that he can take action. Impartial advise to a politician? I don't think so. Not when numerous other climatic influences are poorly understood and they may have some influence on temperatures.

With any luck though, when the spin from the UK conference dies away, we will see some genuine and not one-sided discussion of the possible causes of climate change.

John McLean

John McLean

John McLean’s response does not benefit from a reading of what has been written. I do not say that scientific matters are resolved by consensus, I say that despite the scientific method and the framing and testing of hypotheses scientists nevertheless are people and often behave like other people.

I don’t rely on my originally discovered evidence for global warming. I reference, extensively, the evidence gathered by others. And the point of my concluding comments is that it is very extensive indeed! The hockey stick graph can sustain beatings. Why don’t people like McLean actually go and read the stuff on the several sites I mention such as RealClimate and even Wikipedia. These completely traverse attempts to refute the proposition of warming.

And how interesting it is that McLean does not mention the unexpected rise in CO2 levels reported recently or the news last week of the testing of climate models which suggested future rises of up to 11 degrees C. (The latter probably deserves more analysis than has so far been given.)

To suppose that the Hadley Centre conference is gathering evidence just o satisfy PM Blair is silly. The Centre is not run by any intelligence agency such as the CIA or MI6, so far as I know. What is the personal gain of scientists who conclude that global warming is occurring?

My car dealer service department just called to tell me that the "knock" in the engine is of some concern and they need to pull it down to check the problem. A friend of mine is an engineer and tells me that it is nothing to be concerned about!

Who do I believe?

For any issue there will always be a multiplicity of opinions, options and solutions. If my car expires it cost me money and some inconvenience but I would be less sanguine about the end of the world!

The problem is that global climate change has such profound implications that I am not sure that we can trust political parties to apply non biased intellectual rigour to this vastly complex issue. We cannot have much influence internationally but at every opportunity we should be pressing politicians of every persuasion to reflect carefully on inaction.

After all they are parents and grand parents and if the doom sayers win 6-0,6-2,6-3 it will be a shallow victory indeed.

John McLean wants a genuine discussion on the causes of climate change; fair enough but I don't believe we can have that discussion while ever vested interests are involved and a party preferred "other natural causes" result is the ultimate objective.

Des,

Let me take your points in order.

You say that you are not claiming consensus and yet with the briefest of backward searches I find in your conclusion "First, very large numbers of scientists do consider that warming has occurred in the last few decades, that it is global in extent and rapid, is likely to continue and is due mainly to human activity."

If that is not an statement implying that consensus should rule then what is it?

The "Hockey Stick" can take a beating? I doubt that very much. Mann has still refused, after 4 years, to fully reveal his data and methodology. A principle key of science is that results must be replicable and yet Mann is refusing to provide the information to do so.

McIntyre et al have just shown that the type of analysis used by Mann will easily generate a hockey stick from even random data. (see http://www.climate2003.com/pdfs/2004GL012750.pdf). This adds to von Storch's analysis of Mann's method late last year in which he concluded the "hockey stick" was rubbish.

You didn't mention RealClimate or Wikipedia in your article so forgive me for not deducing that I should read them. Personally I find RealClimate to be a misnomer and UnRealClimate more appropriate. The website exists only to defend established positions, mainly via a series of references to either the IPCC TAR or to papers by those who operate the site. The site is censored and I have seen far too many scientific questions and comments that have been rejected. It is a biased little "marketing" site that should be treated with contempt. As for Wikipedia I don't bother to read it for anything other than very specific information from reputable and credible sources - minor points like the apparently rising sea levels in Bangladesh being due to movement of tectonic plates.

Perhaps you should try my website, http://mclean.ch/climate/global_warming.htm, for information with numerous references. Please read the "eye-openers" before you download the 22-page "summary" document.

There was no point mentioning the press statement last week that claimed that increased CO2 would cause up to 11C degrees of warming because it was a farce. It was marketing masquerading as science. If you had checked the website that it came from you would find that the computer models were greatly simplified and that any results showing "excessive" cooling were rejected (and by implication models showing "excessive" warming were retained).

I have emailed the site to ask what warming "power" they are assuming for carbon dioxide because the Stefan-Bolzmann equation indicates 0.7 degrees for a doubling of CO2 and Arrhenius's work - when the action of water vapour is removed from his data - indicates that a doubling CO2 will result in just 0.22C degrees warming. What was used in the climate modelling? They seem very reluctant to tell me!

To suppose that the Hadley Centre conference is gathering evidence just to satisfy PM Blair is not silly at all.

A press statement from the UK's Met Office on 4 Nov 2004 (athttp://www.met-office.gov.uk/corporate/pressoffice/2004/pr20041104.html) starts with the sentence "Defra today issued details of the conference announced by the Prime Minister in September to discuss scientific aspects of stabilising climate change, 'Avoiding Dangerous Climate Change: A Scientific Symposium on Stabilisation of Greenhouse Gases.'"

and ends with the two sentences...

"David Rogers, Chief Executive of the Met Office said, 'Climate change is an issue of utmost importance. The work of the Met Office's Hadley Centre enables government and other decision makers to formulate policy for the future; this conference is a crucial part of that process.'

"The Director of the Hadley Centre, Dr Dave Griggs, said "This is an ideal opportunity for the scientific community to identify emission levels, especially of carbon dioxide, at which the Earth's climate could be thrown into irreversible change."

There you have it - the conference concentrates on levels of greenhouse gases and is part of the process of advising government.

Since you raise the question of personal gain for these scientists - I didn't - let's see... assured research funding, prestige/reputation, awards (didn't Mann receive one for his graph?). Maybe you should contrast that to the sceptical scientists who are often retired or involved with pursuits where funding for climate studies is not a major issue to them.

By the way, I see you make no response to my comments about increasing carbon dioxide levels not being matched by temperature increase. Nor do you respond to my comments about media outlets starting to become seriously interested in global warming scepticism.

cheers

John

I'm no bleeding lefty but I do know that we can't keep taking from the planet at this accelerated rate.Too many religious people think that somehow God will fix it.Two important things must happen.Firstly get off our addiction to fossil fuels,and secondly make real efforts to reduce our pop. growth.The dinosaurs lasted 160 million yrs."Civilised man" will be lucky to last a hundred more years.

Peter King, how can you have your 'genuine discussion' when you apparently will not accept that 'other natural causes' may turn out to be more significant than man's action?

Computer models predicted Nuclear Winter. Fear of nuclear holocaust waned. The programme parameters were switched to 'Global-Warming'. Too simplistic? Maybe, maybe not. The new "beer and circuses" crusade for the masses is worship mother earth and forsake fire for fear of global warming – and, by the way, nuclear is now 'good'.

Are the models accurate? Do they CORRECTLY predict the weather even 30 days ahead? Clearly they don't and can't. So why trust them to predict reliably 10 or 20 years ahead if the dozens of parameters and interactions are not well understood. There are enough critics, who don't earn their living from the global-warming industry, to suggest that serious problems from global warming are unlikely.

History say weather changes and we adapt. Palaeontology shows us that there was maybe 10 to 20 times more carbon active in the carbon cycle than now - e.g. the fossil fuels correspond to 10 to 20 or more times the current carbon biomass. That is, the earth formerly had much more CO2 in the air. Now if that made things warmer, then the evidence is that it was good - more CO2 makes plants grow bigger and faster – and what do we see in the fossil record? Giant-size versions of plants we know and lush vegetation from pole to pole!

So maybe we should burn more fossil fuel (cleanly) to boost CO2 levels to speed up crop growth! But, more importantly, global warming green house fear is based on unprovable models which depend on dozens of parameter estimates which can't be measured or checked with any accuracy. So why rely on models that will cool or warm just by fiddling parameters.

If it ain't broke, don't fix it!

Miscellaneous: Des Griffin's article was unduly long with irrelevant side waffles:

Waffle-1: What on earth has therapeutic cloning got to do with global warming apart from Des's dislike of Bush and Howard. And on that diversion: cloning has the advantage that there is no rejection from the host cloned, but it has serious practical problems like premature aging, tumours etc - and the moral issue of creating a human for destruction – and it has zero success in curing diseases so far. In contrast, adult stem cells, harvested from the patient, have no rejection problems either – and have had many documented cures to their credit. So why the push for PC TC? Money? Or maybe fame and money?

Waffle-2: Des threw in abortion and population control. But he can't have it both ways. If you absolutely must have cloning to save hundreds of thousands of people, then aborting millions of unborn babies every year should be a no-no. Be consistent Des. If you kill unborn babies because that's more convenient for someone, or to clean up the gene pool, then why not kill sickly people?

Seems to me that those sidetracks Des introduced have very little connection with global warming, rather they seem to relate to dislike of the Judeo-Christian values that Bush and Howard support. Arjay wants to toss in God and dinosaurs too!