alt Hacker News> (Most) libertarians still support addressing externalities.
Not really. They support it in terms of individual responsibility and not as a government role.
> The standard libertarian solution for something unproven would be "it's your job to purchase insurance for this new way of doing things"
No libertarian I'm aware of would force someone to purchase insurance. But it also does not address the externalities problem. We have in this thread an example of an externality that doesn't have a solution. Rolling coal does small amounts of damage. An insurance agent would be happy to insure someone with a modded car that rolls coal because there isn't going to be a claim related to it.
The same is true for any CO2 emitting activity. The damage is an externality that builds up with very small individual acts. I know of no way this would be addressed with libertarian philosophy (grant for me that man-made climate change is real and a problem if you want to argue against this).
> Not really. They support it in terms of individual responsibility and not as a government role.
To a libertarian, a major part of the government's job is to enforce contracts and property rights. Externalities are mass infringements on other people's property rights, that need to either be avoided or appropriately compensated. Emitting CO2 does damage to a common good everyone has an interest in.
> No libertarian I'm aware of would force someone to purchase insurance.
I didn't say the government would force them to. (Though some smaller-scale voluntary association might well do so.)