I believe it is true as an environmental engineer engaged in atmospheric modeling. Atmospheric modeling is a field in which the standard scientific method seems to be working well, that is, there is a large benefit to researchers who are right and/or can prove others wrong. This means that there is a lot of effort going into improving models that are already quite accurate, to the limits of the data you input. For example, the 1990 model of climate change does quite well if you give it better data, and at least correctly predicts the temperature trend with bad data. http://www.huffingtonpost.com/2012/12/10/1990-ipcc-report_n_2270453.html Similar to comments below, the IPCC is an enormous body, and I find invalidating their arguments to require an implausible conspiracy theory. You can look up the executive summary for the various reports at your leisure, they are quite readable.