<rant>First, it occurs to me that a good answer for many scientists, including those in the "hard" sciences, is "I don't know." Probably should use that more often. How old is the universe? I don't know. We have these three models, however, which give us some idea... And so on. A little humility can go a long ways here. Guess what? Average Joe Citizen knows you don't know. Trying to oversell the science is not the way to go.
Second, and more important, this horrible public debate is being framed in the most disingenuous terms possible. I am consistently being told that people either believe in imminent danger requiring bold political action -- or they are science deniers. Pardon me, but that's just bullshit. As the GP pointed out, there are an infinite number of intermediate positions; and no amount of hand-waving about the possible dangers is going to change that.
There are a bunch of logical steps a person must take in order to support political action. Is there a change coming? Are we the cause? Is the change going to cause more harm than good? Can we control the outcome? What is the "proper" outcome? How much action is warranted by the change indicated? And so on. I could list these exhaustively, but it would be pedantic.
This list is not just a bunch of rhetorical obstacles to make sure nothing happens. These are logical and discrete steps that must be looked at and evaluated. Many of them are yes/no questions, but some involve qualitative opinions or numerical differences. If any of these steps come up short, i.e., if there's going to be massive change but the change has more of a positive impact than negative? The whole shebang falls apart. That's not moving the goalposts, that's not trying to throw up a bunch of obstacles. That's just how the reasoning works out.
"The climate is changing" is a trivial statement. Of course it is. "What's left today is a proper scientific theory" looks like a pretty big stretch to this layman. Even granting that somehow we have a falsifiable, reproducible (and how would that work, anyway? Got another Earth nearby?) theory, still looks like a bunch of political types at the IPCC voting on what the change will be. Voting. On the numerical result of a supposedly proper scientific theory. Show me the corresponding physics body that is voting on the mass of the proton and maybe we could get somewhere.
And even then, even if there wasn't so much BS -- even assuming something as rock solid as a huge asteroid heading towards Earth -- a democracy still makes decisions by the persuasion of the voters. I've heard many a climate catastrophist talk as if the average voter is too stupid to make life or death decisions for themselves and the society they live in. If that's what they believe, then we need to start talking about the wisdom of setting up a select group of scientists as the new priestly class, able to understand the mysterious ways of the universe and make decisions about what is just and good for the rest of us.
I've said it before: this is a terrible debate, full of scientists who shouldn't be advocates, politicians who are looking for the latest bandwagon to jump on, the vast morass of uniformed folks who want to look knowledgeable and the poor voter stuck in the middle of all of it.</rant>
As an aside, I would really love to see some discussion about the fact that models based on Cellular Automata always tend towards runaway conditions. Anybody who's worked with such models know this, but it seems to have been left out of the discussion.
I agree with much of what you write, particularly the first three paragraphs. I wanted to make a few comments.
Yes, climate science deals with problems are that more difficult to solve with the "hypothesis->experiment->new hypothesis" approach that works so well for some other fields. People try their best with models and paleo- studies, but it's far, far from ideal. As a result, the IPCC must use other methods to assess consensus.
Many of the fundamental tenets of climate science are reproducible and falsifiable (absorption spectra of the atmosphere with different pollutants; the effect of acidification on marine carbonates; the ways in which glacier ice deforms and flows, as examples). But figuring out how they fit together on the scale of a planet is an enormous challenge.
Ultimately, there's a lot of uncertainty, which some have argued is intrinsic to the problem. What if we can't answer your train of questions in a reasonable amount of time with yes/no? If the answers are variations on "maybe" (they usually are), how should we manage risk? Does ethics come into play?
Finally, there is a pretty rich history of people (scientists included) inadvertently radically-changing their environments because the time scales are too long to grasp.
Apologies for the rant -- I usually don't do them. I just get tired of the same arguments over and over again.
Agreed that the many/most of the tiny pieces of climate science are about as settled as you can get. Nobody's debating the absorption spectrum of CO2. Everybody knows what the temperature of the Earth would be if it were a black body.
But, as you note, this ain't Newtonian physics. If you think about it, the Earth's climate is the most amazingly complex system we could possibly assess using science. We have myriad chemical processes. Add to those a plethora of biological processes. Throw in a heap of meteorological processes. Finally don't forget the astrophysics of the thing. And if you want to have the discussion to the natural conclusion, don't forget geo-politics, economics, demographics, and a pile of other human-oriented sciences.
Geesh Pete, that's a ton of separately enormously complex systems, many of which have huge knowledge gaps, many of which we cannot model well worth a hoot, all working together. To do what? I'm not even sure we understand the question, much less have any clue on how to model the answers.
You also make an excellent point about unplanned consequences of mankind taking various actions. I am reminded of an archaeology article I read a while back about a Roman village. The village was home to a large silver mining industry. As such, the people there prospered. The empire grew. But at the same time they poisoned their water supply. There was much suffering.
I doubt it would be possible to remove most of the ecological changes (I will not use the loaded term "damage") that economic growth has caused without us all living in bearskins and dying of measles by age 30. That's not acceptable. So it's always going to be a discussion about appropriate trade-offs. It's been that way for all of recorded history, assuming the sky gods remain happy, all we have is this reasoning by induction to use on the climate question.
I am honestly at a loss to tell you what the stock market is going to do over the next year. I cannot tell you how the economy will fare over five years. I have completely no idea what changes technology will bring over the next decade or two. Asking for political consensus about what some folks _guess_ might be a few inches of sea level change over the next century? It's simply a non-starter. I don't mean that in a pejorative way. I'm sure folks mean well and are acting in good faith. It's just the entire line of argumentation is far too tenuous, shaky and relies way too much on emotional verve for me to get any traction on it at all. I see a lot of anger, haughty condescension, and political ugliness, but that's just a terrific reason for serious scientists to have nothing to do with the advocacy part of this. There's no there there.
>"Everybody knows what the temperature of the Earth would be if it were a black body."
Not really true, or at least that black body temp is not useful in determining the "extra" warmth. The 255K number is the result of a "simple educational tool" that makes for "a good algebra lesson". I haven't seen what the correct number would be, but probably closer to the mean temperature of the moon ~200K. So there is some combination of atmospheric effects that raises mean temperature ~90K, rather than the usually quoted 33K.
https://www.skepticalscience.com/postma-disproved-the-greenh...
> How old is the universe? I don't know. We have these three models, however, which give us some idea... And so on. A little humility can go a long ways here. Guess what? Average Joe Citizen knows you don't know. Trying to oversell the science is not the way to go.
Yes, but beware the Average Joe who doesn't like the conclusion of those models and therefore seeks "we don't know" as a free pass to disbelieve. Scientific consensus represents the best state of human knowledge so far. I.e. just because we aren't dead sure about those 13.4 billion years doesn't give you free pass to believe the Universe is 6000 years old. Humility is cool and all, but one has to remember that if there was another reliable way to get information about the universe, it would have been incorporated into scientific process.
> and how would that work, anyway? Got another Earth nearby?
Venus. That's where we discovered the concept of runaway global warming in the first place.
> I've said it before: this is a terrible debate, full of scientists who shouldn't be advocates, politicians who are looking for the latest bandwagon to jump on, the vast morass of uniformed folks who want to look knowledgeable and the poor voter stuck in the middle of all of it.
Yeah, it's just a huge mess. That's what always happens when a topic gets politicized - when it can be used to push agendas and persuade voters.
Second, and more important, this horrible public debate is being framed in the most disingenuous terms possible. I am consistently being told that people either believe in imminent danger requiring bold political action -- or they are science deniers. Pardon me, but that's just bullshit. As the GP pointed out, there are an infinite number of intermediate positions; and no amount of hand-waving about the possible dangers is going to change that.
There are a bunch of logical steps a person must take in order to support political action. Is there a change coming? Are we the cause? Is the change going to cause more harm than good? Can we control the outcome? What is the "proper" outcome? How much action is warranted by the change indicated? And so on. I could list these exhaustively, but it would be pedantic.
This list is not just a bunch of rhetorical obstacles to make sure nothing happens. These are logical and discrete steps that must be looked at and evaluated. Many of them are yes/no questions, but some involve qualitative opinions or numerical differences. If any of these steps come up short, i.e., if there's going to be massive change but the change has more of a positive impact than negative? The whole shebang falls apart. That's not moving the goalposts, that's not trying to throw up a bunch of obstacles. That's just how the reasoning works out.
"The climate is changing" is a trivial statement. Of course it is. "What's left today is a proper scientific theory" looks like a pretty big stretch to this layman. Even granting that somehow we have a falsifiable, reproducible (and how would that work, anyway? Got another Earth nearby?) theory, still looks like a bunch of political types at the IPCC voting on what the change will be. Voting. On the numerical result of a supposedly proper scientific theory. Show me the corresponding physics body that is voting on the mass of the proton and maybe we could get somewhere.
And even then, even if there wasn't so much BS -- even assuming something as rock solid as a huge asteroid heading towards Earth -- a democracy still makes decisions by the persuasion of the voters. I've heard many a climate catastrophist talk as if the average voter is too stupid to make life or death decisions for themselves and the society they live in. If that's what they believe, then we need to start talking about the wisdom of setting up a select group of scientists as the new priestly class, able to understand the mysterious ways of the universe and make decisions about what is just and good for the rest of us.
I've said it before: this is a terrible debate, full of scientists who shouldn't be advocates, politicians who are looking for the latest bandwagon to jump on, the vast morass of uniformed folks who want to look knowledgeable and the poor voter stuck in the middle of all of it.</rant>
As an aside, I would really love to see some discussion about the fact that models based on Cellular Automata always tend towards runaway conditions. Anybody who's worked with such models know this, but it seems to have been left out of the discussion.