Very good succinct comparison of tobacco industry claims and the industry funded groups who dismiss global warming. One big difference is we do understand how CO2 can cause global warming unlike the oft quoted lack of known mechanism for the link between tobacco and cancer. To be fair however the statistics are much clearer in the case of tabacco and cancer.

I can understand why people doubt CO2 emmissions are the cause of any difficult to confirm purported rise in global temperatures against a background of high variabiity given other potential causes. I can not understand how anyone can believe that adding a greenhouse gas to our atmosphere will not eventually cause global warming.

We can always add CO2 in the event of other factors favoring an Ice age. We know how to do this. What we don't know is how to sustain or technology and economy without producing CO2 as a side effect. This is an obvious potential pitfall we need to remedy.

It should also be obvious to anyone of average intelligence that natural climate swings can be quite devastating and that waiting for global warming to standout far beyond the normal range in order to believe in it and act is like waiting for an impactor to hit a city before getting serious about detecting and diverting potential impactors.

Regards,
Mark