> Soviet Union was unwilling to put nuclear that far west

That seems wrong; Dukovany (and IIRC then-planned Temelin) were further to the west than most of Poland and operated just fine.

Sulfur can counteract warming (although not the carbon dioxide itself obviously). There was a brief period, right before the world stepped back from releasing sulfur into the atmosphere, when our carbon dioxide emissions were completely countered by our sulfur emissions, when it comes to global temperatures only.