Nuclear power is not an option. There are about three companies in the world that have the know-how to build a nuclear power plant. And they are already at the limit of their building-capacity.

Also, some people argue that the nuclear fuel resources are rather limited and will support even the existing plants for less than 100 years. For a significant reduction (10%-20%. No idea if that is enough to fight global warming) of CO2 emissions, it would be necessary to build at least three times as many nuclear plants as there are today.