[mburbank]

Depends on what you're thinking of. Some pollutants dissipate and break down pretty quickly. Others (I'm thinking of Mercury and other metals in particular) hang around for a very, very long time.

And then there's radioactive waste, some of which will be with the planet probably quite some time after we're not.

That's why W's plan to let power plants buy and sell Mercury emissions is so evil. It's been a succseful program with CO2, but that dissipates and spreads out. Mercury tends to drop within ten miles of it's emission point and get right into the ground water. This plan is going to cuase Mercury poisoning hot spots as older plants buy the right to drop even more mercury than they currently do, and anyone who can't afford to move away has to lump it.

But hell, that scrubbing technology is expensive. And, like most evil enviornmental protections, green technology creates no jobs whatsoever and has no impact at all on the economy.