lsayre wrote:There is now a time when (supposedly) 97% of all scientists believe in global warming, and merely because they are in such agreement they absolutely can't be wrong.
About the only thing they are in agrement with is that the earth has warmed, how much and what the cause is where the debate is. The 97% figure has been pushed by the media and environmental groups. There is only a handful of studies suggesting this 97% figure and there is only one that has directly polled scientists. Since that is the one most widely cited I'll cover that.http://tigger.uic.edu/~pdoran/012009_Doran_final.pdf
Briefly, they sent a questionnaire to approximately 10K scientists in various fields involved with climate. Climatologists, Physicists, geologists, etc. Approximately 3K responded which as I understand it is typical for such a poll. There is some technical issues such as they sent this to official emails and didn't verify exactly who was answering it, e.g. was it the secretary? The second and bigger issue is they were blocking IP's once that IP was used to vote, the problem there is entire campuses could be on the same IP. If someone knew about this ahead of time they could game the system by getting their vote in early. Another issue is who is likely to respond, e.g. if you had a poll on abortion you are certainly going to get a lot of responses from Catholics.
Those issues aside this questionnaire contained two question:.
1. When compared with pre-1800s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?
90% answered risen which is to be expected.
2. Do you think human activity is a significant contributing factor in changing mean global temperatures?
82% answered yes. What is significant? You could argue as many of the scientists have that took this poll that if man was able to affect climate at all that is significant even if the result was inconsequential. "Significant" has no value and could mean completely different things to two different people.
As far as the 97%:
In our survey, the most specialized and knowledge-able respondents (with regard to climate
change) are those who listed climate science as their area of expertise and who
also have published more than 50% of their recent peer reviewed papers on the
subject of climate change (79 individuals in total). Of these specialists, 96.2%
(76 of 79) answered “risen” to question 1 and 97.4% (75 of 77) answered yes to question 2.
In this case the 97% consensus is from a pool of 77 scientists. The other issue is if you are geologist studying ancient climate are you specializing in climate or Geology?
Everyone of these studies has significant flaws similar to this.