Diest TKO wrote:Fair enough. I just object to the notion that GW is a shot in the dark.
Depends on what you mean by "shot in the dark".
The forecasts for future calamaties, such as those in Al Gore's film, are pure speculation and have no foundation in scientific prediction. The reason is that the numerical models for predicting the dynamics of air and ocean currents are themselves unstable and subject to chaos. Their results are valid only for very short range forecasts - a fact that has amply been demonstrated in practice, as Minitax indicated.
We have been in a slight warming trend for over a century. Its origins go back to the natural end of the "Little Ice Age" of the 15th to 17th centuries. The augmentation of this warming trend by human produced greenhouse gases is a real possibility. However the relative contributions of other variables, including those 'natrural' phenomena that created previous ice ages and warm periods are not fully understood by a long shot. Human produced CO2 is a small fraction of the total, and CO2 itself is but a small fraction of the greenhouse gas in the earth's atmosphere. Ice core data show a strong correlation between atmospheric CO2 concentrations and (crude) estimates of global temperatures in the distant past. However, the cause/effect relationships are not fully understood.