How does one measure expertise in a subject area?
According to a graduate student in biology and his co-authors (committee members?), climate change expertise is established by publishing in peer-reviewed journals.
I disagree. Think about the term “peer-reviewed”. Other scientists read submitted papers and recommend which papers should get published. Sometimes they suggest changes before publication. Sometimes they completely reject a paper.
Authors of papers which contradict the majority are less likely to get published. This self-perpetuates as authors who are published are more likely to recommend papers which agree with their own conclusions. The same thing happens with funding. Studies seeking to verify what everyone already “knows” to be true are more likely to be funded than studies seeking to challenge accepted wisdom.
One could argue that single paper published by a scientist who has evidence disproving anthropogenic global warming is equivalent to many papers published by someone supported AGW.