One of the primary means by which modelers have tweaked the models for better results is the inclusion of aerosols. Possible aerosol cloud effects now range from no effect to a near total masking of the alleged manmade greenhouse effect. Many of these scientists still think something should be done to slow down the emission of greenhouse gases. This, however, seems to be a reaction to change as much as a concern over whether there will be any ensuing harm. Although most scientists are willing to admit that there are still large uncertainties in the predictions about rising global temperatures, there has been little effort to quantify those uncertainties.
Uncertainties are important, however.
The Intergovernmental Panel on Climate Change does not provide these numbers, however. Even though it is much more likely that the amount of warming over the next 100 years will be less than 1.4 degrees centigrade than 5.8 degrees centigrade or more, it is the higher number that is emphasized in news coverage of the issue. This is highly misleading if the MIT calculations are correct. The anticipated effects of global warming are supposed to be horrific, according to environmental activists and the science politicos who populated the Clinton Administration. The story then takes an odd turn.