“science is the belief in the ignorance of experts” – Richard Feynman
While expertise is extremely valuable and experts are usually at least worth hearing out, experts are not infallible. They are human and they err like everyone else. Misaligned incentives, political considerations, vagaries of the peer review process, statistical mishaps, lack of replication, rejection of (or ignorance of) other relevant areas of expertise, and the like sometimes creates situations where even quite widely held views are very wide of the mark.
Their work and their assertions can be profitably examined and questioned by non-experts. This is doubly true for what filters down to the public through the media and for what is advanced by advocates. Careful review of the relevant literature and close study of the figures, graphs, etc. contained in cited papers quite often reveals underlying issues in the arguments or otherwise makes room for more parsimonious explanations.
While I cannot claim deep formal training on most subject areas I touch upon here, I typically have at least passing familiarity with the broad surrounding literature and have independently studied the particular topic closely enough to reach my own informed conclusions before I write. Usually I am not so much contradicting the consensus view as marshaling multiples lines of evidence, typically including at least some of my own substantial analysis of the data, and coming out against particular views that are promoted by certain individuals. Regardless, I ask not that you merely take my word for it, but that you carefully consider the evidence and reach your own conclusions.