Talking about like smog in china making people sick? That is a real problem. However I suspect it is one that would go away after about a week if people stopped using coal. I also suspect that coal as an energy source will at some point naturally be replaced by nuclear energy (though not in its current form). I also suspect this is more of a problem with the location of the coal plants than anything else. And finally, the people in these smog ridden cities are probably better off with smog and cheap energy than without smog and without cheap energy.
Well, their coal consumption has been increasing by 10%/year and certainly is showing no signs of stopping, quite the contrary. They have plenty of coal and are busy importing coal. As for the smog I guess that moves around in the atmosphere and isn´t only China´s business. At least this global warming thing is supposed to be a global issue. Strange how real pollution isn´t. But of course it isn´t politically and financially correct and convenient.
The thing you have to consider is that nuclear energy is a million times more energetic than chemical energy. The only reason it isnt profitable now is because we (the species) haven't figured out how to capture it very efficiently. But that will change and there is simply no way that chemical energy can compete in the long term against an fuel source that is a million times as energetic. So yea the trend is up, but it will reverse at some point, you can bet the farm on it.
You're making the assumption that there's competition involved here.