THE benefits listed by John Burgis all came about because of the Industrial Revolution, which successfully harnessed fossil fuel which enabled us to replace human chores with more useful human work. Back-breaking work is now done by machines that derive their power mainly from fossil fuels.

People relieved of chores can learn new skills, so the number of scientists, doctors, nurses, etc, has greatly increased. Families are mobile but dispersed members can keep in touch with cheap telecommunications and transport, but cheap transport is now threatened because of atmospheric carbon dioxide.

The UN Intergovernmental Panel on Climate Change receives submissions from 2500 scientists worldwide, and last reported in 2001. The current report thus has six years' submissions, and that is many thousands of scientific reports. Although the IPCC's "summaries for policy-makers" have attracted the criticism that they are not fair condensation, the full reports are accepted as fair.

In any case, the climate issue will not be resolved by debate but by scientific measurement, which will take many decades, for there are fundamental difficulties. Temperature changes are very slow, a few hundredths of 1C per annum in long-term trend, heavily masked by short-term fluctuations.

We get people alleging that the global temperature is rising faster than at any time in a hundred thousand years, a statement that is not difficult to rebut, for temperatures always rose faster when we were coming out of ice ages.

There is historic evidence of long-term cooling. Before the fourteenth century there was farming in Greenland, pictured, abandoned because the climate got too severe. Between 10,000 and 30,000 years ago there were mammoths in northern Siberia. Like all elephants, mammoths were herbivorous and needed large quantities of green plants. They would starve today in Siberia.

Chris Parton, 40 Bellshill Road, Uddingston. I AM disappointed that, even after the recent IPCC report on global warming, The Herald continues to give prominence to letters by global warming "denialists". The letter by John Burgis (February 6) is a case in point. He suggests that no-one should be allowed to speak on this topic unless they have read a certain book written by well-known denialist. (I will refrain from giving it further publicity.) Burgis, however, has not given us any reason why we should place such importance on the subjective opinion of this single person and, by implication, ignore the opinions of the signatories to the IPCC report (some 2500 scientists who are experts in the relevant field).

The recent disclosure, that many scientists throughout the world have been offered large financial inducements (by AEI supported financially by Exxon/Mobile) to write critiques of the IPCC report, should be a warning to us all.

I would recommend to those of your readers, who want to be more fully informed on this matter, and who do not want to put cash into the pocket of someone who is a well-known denialist, that they should instead trawl the internet for background scientific information. A good starting point for such a search, would be the article they will find at http://en.wikipedia.org/wiki/Global _warming_controversy/ I would also urge them, in making that search, not to be content with press reports, but to trace information back to source, to the articles and press releases coming from the scientific institutions which have made the climatological measurements on which their stated opinions are based. One such can be found at http://scrippsnews.ucsd.edu/article_detail.cfm?article_num=666 which presents persuasive scientific evidence, that global warming is not only due to CO2 emissions, but mainly to man-made CO2 emissions.

Hugh Noble, Creachan, Portnacroish, Appin, Argyll.