[WikiEN-l] Re: Ed Poor not a neutral contributor

One might usefully apply this insight to both sides, I think. It's worth remembering that the CFC process is many orders of magnitude less complicated than the global warming / greenhouse gas question, since the latter involves the earth's entire climate, which is an extraordinarily complex process, and one which is still a long way from complete understanding. So people on either side who express certainty are probably unwise to do so. To digress briefly, it appears from the prehistorical record (as best we can determine it - although useful work has been done with isotope analysis, it's still tricky to determine data from geological records) that the earth's temperature has varied very substantially (without any human input at all, of course) over the course of time, due to factors as arcane as the physical configuration of landmasses, etc. (IIRC, the recent [in geological terms, of course :-] Ice Age cycle is thought to have started when the Arctic Ocean formed.) A good sense of how poorly we understand climate can be seen in our article [[Ice age]], an in particular the section "Causes of ice ages", which makes clear how poorly we understand the operation of the climate. If and when people have a climate model built only on basic physical processes, which can successfully "predict" the pre-historical record, given only the physical data (solar output, orbital path, land-mass configuration, etc) then I think we can be more certain of the contribution made by greenhouse gasses to the earth's climate - but our lack of understanding of the Ice Ages makes clear we aren't there yet. So I'd be wary of edits from people on either side of the controversy. Noel