It surprises me how often people who are not scientists seem to view science as something apart, an area of human knowledge they are not competent to judge. Yet we show much less restraint with the humanities, being happy to wade in and spray our opinions around whatever our level of expertise. At least I am.
Certainly there is an enormous body of factual information and theory in science and that is certainly a barrier to entry. However, we are not necessarily concerned with barriers to entry.
For example, it is often easy enough for anyone to judge scientific work if consequences are part of the public domain. Solar eclipses and the health consequences of smoking for example. Scientific veracity becomes a matter of public record, part of our social history.
A scientific theory not only rests on certain historical facts and is verified or disproved by certain other historical facts; it is itself an historical fact, namely, the fact that someone has propounded or accepted verified or disproved, that theory.
R G Collingwood - The Idea of Nature (1945)
If you ever come across Collingwood’s slim volume in a bookshop it is worth a browse. He takes the reader through an interesting tour of human ideas about the natural world beginning with Greek cosmology.
To my mind Collingwood makes a good point about the historical nature of science. Once scientists enter the public domain via their predictions, offering health advice, supporting official policy and so on, then the general public may judge their claims on the historical record. Whether the claims are right or wrong may be indeterminate, but that too becomes part of the historical record.
So today, when the Royal Society claims certain climate events will occur by 2090, then from Collingwood’s perspective the claim is not necessarily scientific. It depends on the history of similar predictions, on what the historical record says about their success or failure.
Has the Royal Society made similar long-term climate predictions which proved prescient? Obviously not, the RS has no track record whatever in this area. Neither has anyone else. So from Collingwood's perspective the Royal Society isn't being scientific, but something else.
Nobody needs a scientific background to see it.