Nuclear is a lot less inclined to cause global warming. The issue is not the heat expended to do the work. The issue is the CO2 that goes up into the upper atmosphere and traps the heat from the sun. The little bit of heat from the work will probably radiate into space anyway if there aren't green house gasses to trap it. and the green hose gasses produced to make the energy to do the work can continue to trap the heat of the sun and the heat realeased by other work for hundreds of years.

Storing Nuclear waste is not an environmental problem it is a political. I'll bet that sooner of later we'll just be shipping it off to Siberia or the high arctic. or some other desolate wasteland for a fee.