It's interesting that you cite the NIPCC report, but then downplay it as merely political and circumstantial. And since it has a petition, it must be biased, or much moreso than the IPCC report.

Yet, scanning through the 135-page NIPCC report, I see plenty of "diagrams and explanations of the science," which you noted in the IPCC report. Why, then, do you dismiss it out-of-hand?

> Now I don't follow the political debate on whether the IPCC is biased by funding or some other supposed disincentives for scientists to report truthfully.

This is my entire point. It is absolutely crucial. You can ignore it if you want, but you are missing the full picture, and therefore cannot accurately assess the claims of both sides.

> On the other hand I do see that there is less obvious evidence of political bias from reading the published reports.

I guess you meant "the published IPCC reports." I should think that, if any group wanted to push their political view under the guise of science, they would certainly take care to make their reports appear apolitical. Making your judgment based solely on their own word would be like a judge asking a defendent, "Did you do it? No? Okay, you're free to go." You have to corroborate outside evidence to make a reasonable judgment.

> If someone wanted to understand the science it is fairly clear to me the IPCC report would be a much better starting point than the NIPCC report.

Again, the NIPCC report appears to explain much science as well, so it seems unreasonable for you to dismiss it while holding to the IPCC report.

> There are significant financial incentives for people who stand to lose from climate change mitigation, for example in the oil industry, to fund people to investigate the case against climate change.

You're right. And by the same token, there are significant financial incentives for people who stand to lose from not engaging in mitigation. These range from individual climatologists who have built their entire careers on studying the "crisis" of CAGW (if it were determined that there were no risk, what would their careers have accomplished? What would they do next?), to corporations selling "green" energy products and carbon credits, to politicians who are using "climate change" to effect their political goals. For example, Christine Figueres, UN executive of the Framework Convention on Climate Change, recently stated:

This is the first time in the history of mankind that we are setting ourselves the task of intentionally, within a defined period of time, to change the economic development model that has been reigning for at least 150 years, since the Industrial Revolution. This is probably the most difficult task we have ever given ourselves, which is to intentionally transform the economic development model for the first time in human history.

Her stated goal here is not to mitigate the potential risks of catastrophic anthropogenic global warming (which might or might not necessarily entail changing the fundamental economic model of the world), but to transform the world's economic model. This is explicitly a political goal, not a scientific one. The cart (politics) is leading the horse (science).

> I would expect if the scientific case was highly suspect as you'd say that people would have funded equally convincing scientific reports on the other side. The fact that I haven't been able to find such reports suggests to me that there is not a convincing case against the science to be made.

This depends entirely on how much effort you have put into finding them and your criteria for "equally convincing." In fact, many scientists have found such convincing reports--as you yourself noted, at least 9,000 PhD-holding scientists, and about 21,000 non-PhD-holding scientists, who, by your own admission, are more qualified to judge than you. Therefore, how can you so easily dismiss one side of the argument?

I appreciate your being reasonable in the discussion. Thanks.