The Canadian climate scientist, now retired, Dr Timothy Ball, has a guest post at https://wattsupwiththat.com/2018/08/12/the-major-change-in-the-global-wa… … which discusses differences in the IPCC reports of 1990 and 1995 – which is going back a bit – but then he has been involved in the global warming debate for a long time (as a working climate scientist as well as a retired denier of global warming). The 1990 IPCC Report, although limited to human causes of climate change as given it by the UN definition of the role of the IPCC, turned out to be a reasonable attempt to create an historical context for the hypothesis that human co2 emissions cause global warming. He goes on to claim Margaret Thatcher used global warming in her battle with the coal miners union led by Arthur Scargill. It was a very successful ploy as it ended up with lots of coal mines closed down – and seriously weakened Scargill. Hence, global warming has always had a strong link with politics – in this instance the right using it to pummel the left. Acid rain was also used as an argument against coal – a now discredited theory as well. Nowadays global warming is the pawn of politicos of all shades and colours and one is left shaking the head so much so that most people completely ignore the subject. Sir John Houghton, an evangelical Christian according to Peter Warlow in his talk to the SIS many years ago, was the Director in General of the UK Meteorological Office from 1983 to 1991. According to Ball, Houghton brought in a blend of his religious beliefs and science when he was appointed co-chair of the IPCC in 1988. He was the lead editor of the 1990 Assessment Report. In other words, he wasn't involved in troughing or filling his pockets, as some of the people involved were (somewhat later) as he had a clear set of beliefs – and was persuaded by the science. The Report was unique in that it included a reasonable reproduction of the last approximated 1000 years of temperatures for the northern hemisphere – which included input from HH Lamb. It accepted the medieval warm period and little ice age as facts of past climate and even included the notorious figure 7c graph (taken from one of Lamb's books). Ball reproduces the graph for those that have never seen it – as it has been discredited by the climate change clique at the heart of the alarmism. The report also included forecasts – which have subsequently proved wrong (basically extrapolations of warming zooming upwards into the foreseeable future that have actually hardly moved at all).
So far so good. In the 1995 Report precision was removed and this gave greater room for alarmism to prosper and they were able to control variables such as temperature data, sea levels, and co2 levels. They also stopped making forecasts in order not to set up points that might criticise their tactical blueprint. Forecasts were replaced by projections – low, medium and high. Economics was added to the brew – and over population became the focus of another thread. Information was controlled. Politicos knew how to do this and had lots of experience in hoodwinking the general public. Political methods were applied to science – and this has continued to this day. They also gained control of what could be published and what could be rejected in the major journals. Crony capitalism and Pal Review were the commonplace. Between 1990 and 1995 the IPCC thought its AGW agenda was in need of protection as it was being challenged – sometimes rigorously.
Read the whole article at the link above. A piece of history that is useful if one is interested in cutting to the quick.