@RGB
Then I will put your Oregon Petition Project in the trash where it belongs :-)
sorry RGB, I almost forgot to bin this for you, but seeing as you conceded you didn't want to answer my simple question about what YOU think the safe upper limit for atmospheric CO2 is, the least I can do is keep my side of the bargain.
OK I'm now officially embarrassed for you - www.petitionproject.org if you want to see for yourself the offending website.
To read about the flaws in the methodology of the Oregon Project http://www.skeptic.com/eskeptic/08-11-12 if you are interested but to summarize:
The base concept of the Project is an Appeal to Authority fallacy - loads of smart people agree with me therefore you should to.
Compounding this problem is an Appeal to False Authority - how many of the scientists who signed the petition have doctoral qualifications in earth or climate sciences and have made their qualification the basis for their career? A Maths PhD or a Climate Sciences PhD from many decades ago with no ongoing work in a related field are both PhD's, but are to varying degrees irrelevant to building a consensus on climate change. It's like asking Madonna her opinion on the economy of Ghana - she is famous and people may listen, but ultimately she is not the best source of informed opinion.
The methodology of the petiton is fatally flawed. Petition packets were sent to scientists which included a bogus 'research paper' to help these so-called experts make their minds up. Why the need for junk science to be included with the petition? That doesn't sound scientific or even impartial. What kind of survey gives you a skewed view of the science before asking you to sign your name to a position statement that included over 20 separate propositions. Did the signatories agree with all 20 propositions or just some of them? We don't know. How many packets did the organisers send out to receive 31,000 back? How was fact-checking carried out to make sure there were no duplicates, no bogus entries etc etc? We don't know.
And I could go on. This Project is not a fair representation of current scientific thinking on climate change and the organisers have no business representing it as such.