This is the second of two posts that go hand-in-hand. The first post is a brief overview of some important concepts and well established results of psychology that help me think about my thinking. This second post is about valuing scientific expertise and why our non-expert default position should be to believe scientific consensuses, or at the very least, to be comfortable in saying, "I don't know".
You are not an expert (and neither am I)
As Socrates is said to have said, wisdom is knowing that you don't know. A big part of critical thinking is intellectual humility. While it is possible to become an expert at something, it takes years and years of training in a discipline. Think about something that for you this applies to. Think about all the time, hard work, practice and dedication that it took to earn that expertise. Think about all the mistakes you learned from and the pitfalls you now know how to avoid, On that one thing you're probably pretty safe talking at length about all that you know. And when you meet other experts, they can easily recognise you know what you're doing or talking about.
Now think about non-experts and novices trying to talk to you about it. How much credit do you give their views? Well, that's you (and me) when it comes to every other field of human endeavour. It's the ultimate form of arrogant overconfidence to assume your opinion on a subject that you don’t have expertise in has much, if any, merit. And when you dismiss expert consensus out-of-hand, by definition, your dismissal of something you know nothing about is worthless. In fact, it says everything about you and nothing about the experts or their view(s). Imagine a non-expert novice dismissing your views out of hand when discussing a subject you are an expert in?
Scientific (and expert) consensus
A scientific consensus is more than scientists within a field being surveyed for their beliefs or tallying their views in research papers. It relates to what the researchers in a field are interested in studying and why. When there is a question to be answered or a problem to be solved, they'll be researching it and arguing about it; i.e. doing science. But when a question is answered to sufficient satisfaction, e.g. anthropogenic climate change, evolution by natural selection or the second law of thermodynamics, there is little or no incentive to keep researching this question — it's done. Scientists operate within well-established paradigms for a reason — they're well established based on the convergence of theory with data.