I'm not sure whether "green" power generation solutions can be deployed quickly enough to soften the hit of global warming, or if nuclear energy generation is the only CO2-neutral technology that can accomplish that fast enough.
When I read about initiatives and technologies that produce green energy, one thing strikes me as obvious: Most of them require us to live in peace and political stability. Wind farms off the coasts or sun-powered plants in Northafrica (think DeserTec) are a lot harder to defend against sabotage than power plants in a small area your own country.
And don't even ask about the security of this – nonetheless fantastic – way of generating electricity: kites.
The bottom line is that most green energy projects are not only challenges because of the technological and economical conditions, but also due to the need for international cooperation.