Of course, Norilsk's smokestack emissions could, in turn, be greatly reduced -- and the government swears up and down they will be -- but it points up some of the unavoidable realities of the world we live in; namely, there's always some kind of trade-off somewhere.
In the case of catalytic converters, which have helped to greatly reduce smog in American cities and also hastened the removal of lead from gasoline, the trade-offs go deeper. To wit, by catalyzing poisonous carbon monoxide into climate-forcing carbon dioxide, and by producing roughly half of the world's nitrous oxide emissions (NOx is pound for pound, a more potent greenhouse gas than CO2), and by decreasing fuel efficiency.
I want to stress that this is not an argument against catalytic converters. Honestly, I don't know enough about the subject to say how it all comes out in the wash; that is to say, whether or not the trade-off was worth it. Having been in some horribly polluted cities in the world where catalytic converters were non-existent, I suspect it was. The point, if there is one, is simply that we have to recognize that there are not liable to be any perfect solutions and that, when it comes to technological progress, trade-offs are the name of the game.