A relatively minor investment in retraining would allow the majority of coal workers to switch to solar-related positions.

David Biello is the science curator at TED Talks and the author of "The Unnatural World: The Race to Remake Civilization in Earth's Newest Age."

It would create jobs for would-be immigrants and a climate of civility between nations.

Professor at Columbia University and a Nobel Laureate in Economics

Chairman, Berggruen Institute; Publisher, The WorldPost