Does John Christy agree with the IPCC on human-caused global warming, or is Judge Sessions a liar?

I think the problem is denier sites tend to misrepresent Christy's position as he has said that the the prediction models are not accurate, this is not really controversial and is the reason groups like IPCC have ranged temperatures in their future predictions allowing for these inaccuracies.

Another example would be the Mann hockeystick graph which deniers continue to falsely claim has been completely discredited,

http://www.newscientist.com/article/dn11646

Not only has a NAS report not discredited the report, you will find John Christy's name on this 2006 report as one of the committee members (page 10)

http://books.nap.edu/execsumm_pdf/11676.pdf

eric c

"We know that Christy is a co-author of a paper that says that clouds act as a negative feedback, and not a positive feedback as the IPCC maintains. If clouds act as a negative feedback, there is no way we could have recorded the temperature increases in the late 20th century that we have. So we have a contradiction in Christy`s statements."

On a day to day weather basis clouds can be both depending on when they form they can trap heat or block heat but averaged into global climate their effect is minor.

Without knowing what Dr. Christy said about water vapor, it's hard to know if the deniers could do better. It sounds like Christy conceded a lot of key points. My experience with expert witnesses is that they are extremely unpredictable. You go over their testimony with them several times before trial, and yet when they get on the stand, everything they say is qualified and caveated to the point it all boils down to about nothing. You can go through the transcript line by line, and what they said in lines 1 to 15 is taken back or qualified into a nullity in lines 130 to 145, and what they said in lines 45 to 60 is caveated into nihil in lines 235 to 250. When you're done with the analysis every part of the transcript cancels out some other part and the net residue and remainder is a big fat bowl of zero. They do take up a lot of Court time though, and they enjoy being on the stand, and they like to put a lot of biographical detail into how they got to be so smart and expert. For that reason, panels of scientists are a better source of good science than are Courts. Most judges are science ninnies. So even if they do their very best, it's a little like brain surgery with a wooden spoon. Heisenberg talked about the idea that the event is changed by the process of observing it. So if we put the electron on the witness stand and ask it how it became such a fast electron, it gives and unreliable answer --- well it's the same with expert witnesses.

Christy, as do many other skeptics, support that co2 could cause warming subject to many uncertainties. The difference is however, that they believe the rise in co2 will only have a small effect and will not cause catastraphe.

I dont know the history behind his comment, I suggest you ask him via his blog for the background, give the man a chance to explain himself.

I in fact agree with many of the IPCC reports statements such as the statement that even though temperatures have risen this centuary the cause may be entirely natural and no anthropogenic signal has yet been found. Who wouldnt agree with that?

An interesting quote from the report:

"Plaintiffs’ expert Dr. Christy estimated that implementing the [co2] regulations across the entire United States would reduce global temperature by about 1/100th (.01) of a degree by 2100. Hansen did not contradict that testimony."

As a skeptic, I'm looking at this as a ''Glass Half full'' situation.

To answer the quetsion....

1) John Christy agrees with the IPCC on human-caused global warming

which, lets be honest, shouldn't really be much of a surprise, seeing as he a lead author of the 2001 IPCC report.

The fact that he is (for want of a better word / phrase), a 'Partial' skeptic should surely give skeptics a boost.

Surely if the lead author of an IPCC report, doesn't believe Al Gore etal on their ''catastrophic'' and ''at a tipping point'' claims, it's a good thing ? yes ?

can someone top me up - Stella , thanks :)

His testimony was crystal clear, as summarized by the judge: "Dr. Christy, agrees... most of the observed warming over the last fifty years is likely to have been due to the increase in GHG concentrations."

The IPCC however goes far beyond a simple communication of the data. It's likely that Christy agrees that current global warming has ample contribution from mankind's greenhouse gasses, but he apparently is skeptical about the scope of future warming. That's a healthy topic for scientists to take various theories on and make their case, to see which ones are determined on the basis of the evidence to be most likely. Christy's role is important to prevent laymen, especially politicians, from over-reacting (or under-reacting). His role in fighting reductions in auto emissions is not so positive.

I don't view agreeing with the IPCC in general as being a positive influence on the discussion. It is obvious for any rational person to question the efficacy and wisdom of letting the largest emitters with the fastest emissions growth rates (such as China) exempot from emissions limits in all current and proposed treaties. To anyone who accepts the stronger predictiosn of warming by the IPCC, the U.N. is effectively advocating suicide via Kyoto-like treaties. Who in their right mind would propose that, let alone sign on for that?

Our biggest savings in future emissions would be to prevent China and India from copying the commutes-required urban planning and infrastructure of developed nations. As long as the U.N. is not very strongly advocating that simple savings, and demonstrating through projectiosn that world emissions will acutally decline (not the case at all with their current proposals), the credibility of any plan they propose remains seriously in question.

We know that Christy is a co-author of a paper that says that clouds act as a negative feedback, and not a positive feedback as the IPCC maintains. If clouds act as a negative feedback, there is no way we could have recorded the temperature increases in the late 20th century that we have. So we have a contradiction in Christy`s statements.

This makes one question what were the circumstances that lead the judge to come to this conclusion. Is he quoting him directly, or is he summarizing what he thought he said? Did he base it on his AGU statement? That statement was made in 2003. Five years ago. So if anything given his current statements you can say he is becoming more of a skeptic, and not a "delayer" (as climateprogress likes to call him). And he has said that he would only agree to sign it, as long as no numbers were attached.

The judge that made the ruling is a liberal judge appointed by Clinton. If you believe that judges are impartial and not subject to politics, then there would be no need for the Senate to approve a judge would there? I am not saying he intentionally lied, but it is common trait among people to hear what they want to hear, and judges are not immune to this human trait (as much as we like to think they are)

Christy out of principle does not receive any money for his skeptical position. So it makes no sense for him to play the skeptic, when in fact he is a believer. There is more grant money to be made as a believer. Your papers get published more easily. You do not have to endure harassment and death threats from the public.

The final point is why would the blog cliamteprogress make such a big deal out of it? Why would they use the word "delayer" saying that all skeptics eventually see the light and become believers. It seems to me that many believers are starting to question the AGW theory, and this is a way of saying "hold on to your faith", even skeptics are becoming believers, there is no need to question the theory.

Antarctic ice: Hear it from the horses mouth if denier sites are misrepresenting Christy:

http://www.youtube.com/watch?v=-WWpH0lmcxA

Number # (4) he gave his testimony to what was on hand. Not future predictions which the IPCC acknowledges as a "what if factor".

http://www.ipcc.ch/ipccreports/tar/wg1/466.htm

Would that make the IPCC fall into the category of skepticism?

When I have to choose who to trust, climate scientists come in right behind trial lawyers and television pitch-men. I trust the judge.

And no, I don't even need to hear what they're talking about, and don't care anymore. I have recently come to assume that anyone saying the earth is warming is either wrong or lying, until proved otherwise.

I would say that without the dire consequences, very little needs to be done about global warming. That is Christy's position. We don't need kyoto. We don't need carbon taxes. We don't need everyone to drive a Prius. That is the option that matters.