I recently criticized the study Doran and Zimmerman 2009 because of poor phrasing in their survey questions. I’ve looked at some other attempts at surveying the climate field, which I may write about later, but I haven’t found a satisfactory survey yet. The problem is that while the surveys ask if human activity has influenced climate, they don’t ask how significant it has been. For example, if a climate scientist believed that human impacts have increased the global mean temperature by one tenth of one degree, then they would answer yes and be considered ‘part of the consensus’. I verified this by asking several famous ‘skeptical’ climate scientists to answer the questions used in the Doran 09 survey, and they answered in the positive.
This led me to consider what kind of question would be sufficient to determine just how significant climate scientists believe human activities have warmed our planet. I put forth this as a question:
Do you believe that anthropogenic greenhouse gas emissions were the primary factor (50% or more) in the observed mean global temperature increase since the mid-20’th century?
While I consider this better than the other survey’s questions, I still think it is flawed. I’m curious to know exactly how much climate scientists believe we have warmed the earth. So here’s my new question:
By how much do you believe anthropogenic greenhouse gas emissions have increased mean global temperatures since the middle of the 20’th century?
B. Less than 0.1c
C. Between 0.1 and 0.3c
D. Between 0.3 and 0.6c
E. Between 0.6 and 1.0c
F. More than 1.0c
I would also like to see a question on climate sensitivity, with different ranges as answers.
These surveys have always been crafted by believers in the consensus. What would this type of survey look like if created by those skeptical of the consensus? Let’s find out. Feel free to comment on what you would like included in a survey, and how you would phrase the questions. If we do well enough, we can look at doing this informally, or if someone knows a social scientist who would be willing, we could actually do the survey up right.