[infogulch]

"Negative externalities" seems to be the operating pivot of this conversation. It seems to me that many laws are a system to identify entities producing negative externalities, and make them bear the cost of that externality. The purpose of the lawmaking process, then, is to be a system that discovers new externalities, or more precisely, defines what is a negative externality and what is not, as it relates to chosen policy.

At what point in the progression of scientific consensus does evidence for the consideration of a new externality require a response by passing laws that define the externality and how it can be bourne?

One argument is that there is not enough scientific basis to ground policy regarding CO2, specifically. And, separately, there is enough evidence that some forms carbon energy should be restricted, but due to other factors like pollution from coal. This argument is coming from a strong negative-rights model of government (like the US), where axiomatically people are allowed to do anything not currently restricted by law. The advantage of this system is that it allows people to act in the face of ever-changing circumstances of the world without needing to get approval from the government every time a new thing is discovered. The disadvantage is that now you have to hold externalities to higher bar of proof.

I think that we, individually and as a society, still have to act in the world, imperfect information and all. We cannot demand perfect data to base our decisions on, because always waiting for perfect data means that every decision will be too late. But, just like in science, we need to be able to change our beliefs/laws as evidence mounts that the basis for our previous belief is wrong. The problem is that politicial discourse is so deadlocked on pure narratives (all negative or all positive, no room for nuance or complexity) that we'll never be able to agree.

[bobbydroptables]

Yeah you're pretty much right. But this can be solved pretty simply with a pigovian tax.

It's not inconsistent with any definition of rights that I'm aware of to say that you can't pollute our air without consequences. By contrast, the current state of affairs does not mesh with any philosophical system that I've found. Under what theory can some stranger pollute my air? That's no more justifiable than me pouring perchlorate in my neighbor's well. The stronger someone believes in individual rights, the stronger they support my argument.

I think it's a misreading of philosophy (not saying you're doing this) to say that we need to justify restrictions on obvious negative externalities like air pollution. The polluter needs to justify his actions, not the neighbor whose air is being poisoned.

(The science on the deleterious effects of air pollution is of course settled regardless of what anyone thinks about global warming.)

[infogulch]

I think the problem with your argument is that you assume there is always an a priori agreed upon definition of what constitutes negative externality, and this is just not true. Specifically, the line (emphasis mine):

> It's not inconsistent with any definition of rights that I'm aware of to say that you can't pollute our air without consequences

What exactly does pollute mean here?

I could say that my neighbor generating sawdust while sawing wood to build their deck is "polluting" the air. Or me sneezing while standing on my porch outside is "polluting" the air. Or if I'm watering my plants and some water flows downhill to my neighbor is "polluting" their lawn. Or me practicing piano in my house is polluting the soundscape of the neighborhood. Or, ..., or, ..., or, ..., or, ... See, there are limitless ways that one could construe basically any action someone takes as producing a negative externality. Almost certainly all of the examples I mentioned have been argued as negative externalities, and the answer is not to either accept every argument or reject every argument, because the details and circumstances matter.

My point is: Don't presume that negative externalities are automatically identified, and don't presume that every identified negative externality automatically justifies action to correct it, and don't presume that your chosen favorite corrective action produces no externalities of its own.

To be clear, I agree that there is enough evidence against CO2 that it is worth considering taking action to force CO2 generators to bear the cost of the externalities they produce. I don't agree that it's "obvious" that: 1. the negative externality exists, 2. the chosen remedy will actually solve the problem, 3. that the chosen remedy is known to be sufficiently free of its own negative externalities to consider forcibly changing our behavior. I think these things are true, but I don't think it's obvious that they're true, and trying to assert their truth by trying to make them axioms is dangerous and counterproductive.