Yes, pollution can be regarded as an initiation of aggression similar to theft. (It's not a problem with libertarianism that state court systems -- and for that matter, state licensing and regulating -- have allowed all this stuff to happen and failed to regard it as a problem.)
You're tilting at windmills over the things you think libertarians think, when the system that's currently in place has proven itself entirely ineffective at policing climate.
@kennyskitchen basically laid it out, but of course taking responsibility for yourself isn't the answer you were looking for. What you want is an excuse to micro-manage other people under the guise of fixing a problem, whether or not you're effective at fixing it.
Libertarianism won't give you that, but it does give you every single possible way to help solve it p2p and peacefully.
Going forward, in a truly decentralized world, you'll probably have reputation based (court-like) systems that incorporate a person's footprint, just like you need a way to track who is a rapist, who owes money on bills, etc., and this would be a practical incentive for people to treat the planet well.
Or more inside the box, libertarianism at least doesn't actively create problems, like subsidies to the meat and dairy industry or a transportation system that begs for everyone to pollute whenever they go somewhere. Or global warfare for that matter.
Without those things, and without a court system that wouldn't dare hurt the interests of their corporate pals, I'm not sure the problem would really even be a thing.
(But blame peaceful cooperation.. ya.. ::rolls eyes::)