A good question.
What are the qualifications to be a climate scientist? Papers published? Degree major? Years in the field?
Are the qualification requirements stable or change over time?
Who sets the qualifications?
Who decides their position on the issue? Is there a degree of hedging allowed?
MSM and Science don't mix very well, yet MSM influences voters of the low information kind.
A more motivated FReeper than I did a bit of digging, and found out that the "scientists" quoted were public policy wonks and lawyers. There was one person in the group who had a degree in something semi-related - Geology maybe - but the rest of the people were just useless eaters.
Sez me, I'll take an opinion formed from my own engineering background, and the common sense displayed by FReepers in general, over that of a bunch of lawyers.
Were it only that the media had such common sense, as well.
That number - the 97% - comes indirectly from a thesis paper a student was writing for his master degree. He sent out 10,400 surveys to folks in the field and received 3,400 replies. As part of the survey, the folks replying had to check a box indicating their vocation (meteorologist, environmental scientist, climate expert, geologist, etc.) There were about two dozen different occupations from which you could choose. Seventy-nine of the 3400 respondents checked the climate expert box and all but two of them were pro-global warming (err, climate change).
BTW the paper raised a number of valid points concerning shortcomings in the global-warming (uhh, climate change) argument. But nobody who quotes the 97% figure ever acknowledges the valid points.