There's that "expert" again.
Keep in mind that we are not talking about scientific research in this particular case, but a simple analysis of a group of abstracts, something a very intelligent high school student could probably handle.
What was Oreskes' climate science background? She's a geologist and history professor, who wrote an essay, not a reviewed paper, on analysis of a bunch of abstracts. She is obviously qualified to do this, climate background or not, and you'd have a hard time pointing out any professional who couldn't handle it.
I'm belaboring this point because the Argument from Authority seems to be becoming a lot more important than the actual information.