The problem isn't smoking in smoking areas, its when people don't stay there, or when they decide that anywhere and everywhere is a smoking area. Your right to smoke is just as equal as non-smoker's rights to not have something they find disgusting blown into their face, or to be exposed to something that is generally agreed to be harmful. Should you be able to smoke? Of course, smoke as much as you like. Should everyone else have to put up with it? No. Saying that your right to smoke wherever you feel like it is more important than the rights of non-smokers to not smoke or be exposed to smoke whatever their reasons, is perhaps, a good way to invalidate your argument.
So rather than addressing the simplest and most prevalent one, we should...what, precisely? There are plenty of environmental problems. Hell, if you use a refrigerator, or aerosol cans, you're causing environmental problems. There's sort of a difference between equating a globalised problem with a globally occuring local one.