It isn't. The Petition Project is exceedingly dubious. It's an appeal to authority, which is always a worry and it is an appeal to false authority, which is just plain dishonest. I have scientific qualifications and 15 years of experience working in a scientific field. However, I am not qualified to comment very convincingly on climate change and people would be right to treat any claims I made about the climate with open contempt. Randi's skepticism seems to have deserted him with this post.
There are other concerns. For example:
This ball of hot rock and salt water spins on its axis and rotates about the Sun with the expected regularity, though we're aware that lunar tides, solar wind, galactic space dust and geomagnetic storms have cooled the planet by about one centigrade degree in the past 150 years. The myriad of influences that act upon Earth are so many and so variable -- though not capricious -- that I believe we simply cannot formulate an equation into which we enter variables and come up with an answer
This a hugely complex set of variables we are trying to reduce to an equation...
It's certainly the case that the climate is complicated. However, Randi's argument is a bit of a straw man. This is what I posted on the JREF site:
This isn't what climate scientists are trying to do. They are trying to understand more about how the climate works, with equations being one of the tools they use to do this. Others include experiments, other types of model, new ways of measuring the climate's properties, observations of different kinds of thing, examination of new data, new ways to examine existing data etc. Predictions about the climate's future are based on lots of different factors put together in lots of different ways and the answer in each case will have error bars. One of the tricks is to learn where these bars are, how big they are and whether we can do anything to reduce them.
To suggest that the aim is to 'reduce' the complex system of the climate to an equation is leading language and an oversimplification. The hope (or rather, one of the hopes) is that better models, better measurements and increasing understanding of all the factors involved will increase our ability to predict the climate's future and our ability to assess how confident we should be of the results.
In other words, it seems on the face of it that Randi has acted a little rashly and has perhaps been a little misguided on this issue. Phil Plait agrees:
Instead of rending my garments over this, I read Randi’s post carefully, and then sent him a note outlining why the Petition Project is a crock, as well as saying that yes, mathematical models of climate are very complex, but that doesn’t change observations indicating the reality of global warming or our role in it.
Unfortunately, a lot of the comments to Randi's post are downright chauvinistic. Many people are claiming disappointment with Randi. Some claim they are planning to withdraw financial support from the JREF on the basis of the post. Some are suggesting that Randi has lost his marbles. Some say he has somehow hurt the cause of skepticism with this post alone (regardless of his lifetime of service to that very cause). This seems an astonishing overreaction. All Randi was really saying is that he is skeptical of the scientific consensus. He's not denying AGW, he's saying he's an amateur and doesn't really know what he's talking about, but that he feels it's worth being skeptical about the consensus.
Now it's clear that Randi was wrong about a number of things and that this isn't his finest hour. His skepticism seems to have misfired. For the most part, this seems to have been due to his ignorance of the science.
Phil Plait educated Randi about some of the issues and Randi responded here.
Personally, I think he cleared up many of the concerns in this post. Others (including some in the comments and PZ Myers) disagree.
But what the hell. The point is that Randi began by saying he didn't really know what he was talking about. He screwed up and was reamed for it. He admitted he was wrong and pointed out that he was sure to be wrong again in the future. It's the feelgood story of the year, isn't it? Well, perhaps not, but it's an everyday story of skepticism. It's an interesting episode and reminds us that although skepticism can be considered a movement, it isn't a dogmatic one. We're all different and we all disagree. I'm not sure why Randi's comments elicited such vitriol and I think it's regrettable. Although we should apply the same standards of skepticism to Randi's writing as to anyone else's, I think he's earned a certain amount of trust and the benefit of some doubt.
Either way, I'm deeply uncomfortable with those - including PZ Myers - who say that Randi has somehow hurt the cause of skepticism. I think the man was just wrong. Give him a break, he's quite old and he's very ill. We all make mistakes and the fact that he's spent a lifetime working for the cause of skepticism doesn't make Randi immune.
Give him a break and give him your money. Whether you agree with Randi's stance or not, the JREF is an excellent cause.