Neither leaded gas nor CFCs were eliminated because of capitalism. They were eliminated in spite of it. Companies got dragged kicking and screaming into compliance because of regulatory oversight, which is anathema to pure capitalism.
Neither leaded gas nor CFCs were eliminated by communism, nor did communist governments do a particularly good job at eleiminating their use in an extraordinarily expedient way or anything.
In fact, leaded gas and CFC elimination in communist regimes happened exactly the same way (via regulation/treaties).
Regulations are universally needed to account for negative externalities-- just look at soviet superfund site equivalents (like lake Karachay) and tell me with a straight face that communist administration solves those problems by itself "without dragging anyone kicking and screaming".