What If They Are Wrong?

Judy Curry dares to report on her blog the questions posed on Mike Stopas blog:

• Suppose it turns out that CO2 has essentially nothing to do with the earth’s climate. How will the history of this colossal mistake be written?
• If someone were, for instance, to come up with indisputable evidence tomorrow that CO2 has essentially no impact on earth’s climate, could the world accept it?
• With the development of frakking and the concomitant extension of carbon based energy resources hundreds of years into the future, what would they do with all the windmills?
• Well, the truth of this issue should be apparent within about 15 years…at which point we may be allowed to buy incandescent light bulbs again.

Judy does not know what to say but says something anyway:

• So, is a scientific revolution underway and/or needed for climate change?
• I don’t know, it is certainly possible that the existing paradigm can be embellished as our understanding of the complex climate system increases.
• However, as scientists, we need to acknowledge that the consensus needs to be continually challenged, and not dismiss anyone who challenges the consensus as ‘deniers.’
• I think Stopa is about right when he says: Well, the truth of this issue should be apparent within about 15 years.

What Judy says is that "it is certainly possible" that CO2 has no effect on climate. This statement is in contradiction with the current consensus that "it is certain that CO2 has an effect on climate". Judy probably means by "certainly possible" that chances are somewhere between 25 and 50% that CO2 has no (detectable) effect.

So Judy challenges consensus, but does not want to be dismissed as "denier". Welcome then Judy to "the challengers".

As challenger, we do not have to wait 15 years for evidence of zero effect. We can right now scrutinize the existing scientific evidence that CO2 has an effect. Isn't that what we should do Judy? What is this scientific evidence in fact, Judy?