In the real world: no, forever and none at all.
In the real world the productivity, and hence the emmissions, would simply be taken up by somewhere else. This is one of the biggest problems facing the Copenhagen conference. If the US, or indeed the entire developed world, reduce emmissions without either drastically reducing their standard of living or ensuring a concommitant reduction in the developing world, the only result will be that the developing world wil take up the slack and increase emmissions to the same degree.
The fact is that people will want aluminium foil as long as they can afford it. The only way to make them not afford it is to reduce the standard of living which is political suicide. So the alternative is for the US not to produce aluminium. At which stage, because the demand is still there, production will increase in the developing world to take up the slack. There’s no advantage to this, and in fact it is counter productive, because developing economies tend t produce more greenhouse gases per unit of product.
The US unilaterally switching to zero emmissions mode won’t do a damn thing unfortunately.
If we follow some of the suggestions on the table ATM, developing countries are expected to reduce their emissions by much less, or actually allowed to increase emissions, in addition to which they will be compensated for any emissions reductions they do achieve over business as usual. Under that scenarios more industry will move to developing countries and the poor in those countries will be much better off.
If you mean under a scenario where everybody reduces emissions, that’s highly debatable. Reducing emissions means making everything more expensive. IOW everybody becomes poorer, but people in the developed world are hit relatively harder. That means fewer taxes, less charity donations, more people in poverty at home, less purchasing of foreign goods and an inevetible decline in both foreign aid and foreign spending. That ain’t gonna be good for a factory worker in Delhi of Beijing.