So if I understand you correctly, Jim, the Cato ad on climate change “is neither very relevant nor helpful” because (i) it implies there is no reason for alarm, and (ii) the scientists didn’t explain “both sides of the issue in terms of the deep uncertainties that surround it.”
Regarding (i), I suppose it depends on what you mean by alarm. Even if we accept the absolute worse case scenarios of future warming offered by the IPCC and the Stern Review on the economics of climate change, we still find that a hotter, richer world (that is, the likely path for a business as usual scenario) is better for human well-being than are the alternative scenarios where we actually act to reduce greenhouse gas emissions. If that is correct, then alarm should be reserved for worries about overreaction to climate change, not climate change per se.
Regarding (ii), we are guilty as charged. Even were we (Cato) inclined to pay for hundreds of thousands of dollars for ads like that (and we are not), scientists disagree about where the important uncertainties are and how great they might be. For instance, there are scientists who signed our ad (such as my colleague, Pat Michaels) who accept the conventional (IPCC) narrative regarding the role that anthropogenic CO2 is having on global temperatures. Others do not.
That said, the ad forwarded three claims about the uncertainites with science undergirding alarm at present (that there has been no increase in surface temperatures for over a decade now, that the extreme weather events that we’re supposed to be worried about have not increased damages once we control for other variables, and the computer models are not very good at predicting future temperature). The ad did not say there was no reason for alarm. The ad said that the case for alarm is overstated . . . given those three observations. That we chose to be brief rather than verbose on those points was a tactical call relating to the nature of the venue.