I'm definitely not educated enough to answer with nuance and certainty to some of the questions you posit. Nevertheless, I'd be interested, actually, in your opinion of what constitutes 1) evidence and 2) consensus. I, personally, have an intuition for it, but it's not very reasoned out. I'd love to develop it more in the future.

You argue that consensus is not really required in "hard science judgements". While I haven't studied proper philosophy of science, I'd say "measure things or do an experiment and be done with it" is, precisely, among the best ways to produce/allow consensus; or rather, the capacity of 'hard' science(s) to reason about a series of phenomena in such a way that consensus is 'easy'. One could argue that precisely the phenomena that 'hard' science inspects lends itself more to be inspected under a strict scientific method, too.

I'd say that any 'fact' is dependent on consciousness and intersubjectivity; yet at the same time, some things are more factual than others. Gravity as a phenomenon is more factual than, say, the Stendhal Effect. One can be more and better reproduced under more stringent conditions, thus having more predicting power and being more likely to be 'true' regardless of who interacts with the phenomenon, or reasons about it and its implications.

>I'd say that any 'fact' is dependent on consciousness and intersubjectivity; yet at the same time, some things are more factual than others. Gravity as a phenomenon is more factual than, say, the Stendhal Effect. One can be more and better reproduced under more stringent conditions, thus having more predicting power and being more likely to be 'true' regardless of who interacts with the phenomenon, or reasons about it and its implications.

Yes, this is my point. The question of, for example, measurements of gravity (at the basic Newtonian level for non-relativistic speeds) is more factual and less nuanced than the question of "climate change" or the question of "quantum explanations of gravity".

Reducing these more nuanced (or "less factual") issues to "people who don't think those are clear and settled are mentally affected" is a psychologization of dissagreement, turning it into a pathology.

It's worse when the proposed solutions / policies are also bundled with the facts (so you need to accept both to be "within the consensus").

While I understand the idea (there are nuances) I wonder if we treat things fairly. I have never measured gravity directly. I can notice effects which I know are attributed to gravity (things falling), but then again I can see effects attributed to human CO2 emissions (weather getting warmer and crazier).

The scientific concept of gravity (as I remember it from high school) involves two bodies and the distance between them. I can't measure that at all, so someone could claim gravity does not exist, but things fall because of some other reason.

What I think it's more important is the system's complexity. Describing gravity as "two objects, bigger one attracts smaller one" is simple. Climate system is very complex and even if you describe "CO2 (a transparent and 0.04% part of the atmosphere) causes a warming of couple of degrees" sounds harder to picture.

Yes, the complexity of verifying/checking is a major factor of that "nuance".

In the end, Newtonian gravity's complexity can be boiled down to a few formulas, and those describe the phenomenon (and are quite simple). Something like climate change causes, progress, rate, and so on, even with many basic assumptions taken for granted, is still a huge and multivariate issue.

One can see that "weather's getting warmer", but it could be a process repeating every N centuries or millenial, and we're just at that point, others might argue the effects are not as dire as argued, or the rate not as fast (e.g. many public climate doomsday predictions have failed to arrive when the dates came and went). Or one might totally disagree about the proposed solutions (or with who and how gets to implement and impose those solutions, another can of worms).

That's more like string theory level nuance (which theoritical physicists still debate variants off, and some hardcore scientists even believe is speculative crap, and which in any case is nowhere near settled), than Newtonian gravity level nuance.

> Consensus is not really required in hard science judgements where you can just measure things or do an experiment and be done with it.

This is not true. Hard science judgements still require consensus and one experiment does not prove all that much.

>Hard science judgements still require consensus

Only a trivial one. Which is not really challenged.

Nobody really questions the value of the acceleration due to gravity down on Earth, or whether a body with mass X and another with Y will both fall at a rate R in a vacuum for example. And if they do, a simple experiment will show them otherwise.

There are people who question that the Earth is a sphere.

I'm aware. Perhaps it's a sign that it is more nuanced than "things on a vaccum or with the same aerodynamic profile fall at the same rate regardless of mass".

That one people can more easily check: they can go an the tower of Pisa (or a high building) and drop things.

The latter requires either taking the assertion that it's a sphere without question, or understanding the impact a non-spherical earth would have on things like visible orbits and so on. The math might not be novel (they already knew them since antiquity) but they're not trivial either.

And of course basic empirical checks also favor a flat Earth. Short of checking out and calculating orbits, or getting into some big mountain, the most basic observatiosn is that the ground appears flat - which is a good approximation to what is the actual case, given that limit of the curvature at such small dinstances being quite "flat".

It was reasonable for people to regard the Earth as flat so long as there was no good evidence to the contrary, but one would not call it a matter of consensus today just because some people might be unaware of the evidence, fail to understand it, ignore it, or choose to deny it without attempting to refute it. Alternatively, one were to insist that this means that it is still a matter of consensus, then that would amount to defining 'consensus' in a way that is useless for this discussion.

The bleaker truth about evidence, facts and politics is that people are arguing for a preferred outcome, and will, to a greater or lesser extent, simply turn to rationalization (sometimes of a quite irrational type) if the evidence does not support their preferred outcome.

> Only a trivial one. Which is not really challenged.

"Hard science" still has quite a lot of disagreements in it. The questions you cited had consensus forming quite a long time ago and are trivial now. That does not mean there was no period of consensus forming or that we do not need that consensus forming for actual current scientific questions.

Science is not limited to yesterdays questions.

Reminds me of that book: 100 Authors against Einstein to which Einstein retorted: "If I were wrong, then one [author] would have been enough!".

https://archive.org/details/HundertAutorenGegenEinstein

Also something subtle is that it is remarkably difficult to take the position of "I don't know what my standard of evidence to justify acting" and still look credible. Unless people stop and really think they'll basically write the position off as someone exiting the debate to leave it up to others.

As a practical matter there are people who will shout "climate change" as a cover for status plays. And unfortunately they seem to have determined that a high status display is making energy expensive. These people are much more of a risk than anything the climate is likely to throw at us.

It sounds a bit funny to say, but the bureaucrats who made Nazism and Communism function weren't unusual monsters, they were people made up of the same stuff as the current crop that governs us except with ideologies that didn't work out in practice. The risks of going in to the energy grid with a new ideology that sounds good are really quite high. They're perfectly capable of letting millions of people suffer horribly rather than admit a mistake.

People have sniffed big chunks of that out, they are very tuned to status games, but it is so hard to articulate without sounding crazy they don't bother and just end up looking silly when people keep bashing them with ever more evidence that the temperature is rising.