Some studies suggest that the Arctic Ocean may be ice-free by the end of the century.

One thing you can say about nuclear power: the people who believe it is the silver bullet for America's energy problems never give up.

Americans don't pay much attention to environmental issues, because they aren't sexy. I mean, cleaning up coal plants and reining in outlaw frackers is hugely important work, but it doesn't get anybody's pulse racing.

Have we failed to slow global warming pollution in part because climate and environmental activists have been too polite and well behaved?

Climate change is a global issue - from the point of view of the Earth's climate, a molecule of CO2 emitted in Bejing is the same as a molecule emitted in Sydney.

In reality, Republicans have long been at war with clean energy. They have ridiculed investments in solar and wind power, bashed energy-efficiency standards, attacked state moves to promote renewable energy and championed laws that would enshrine taxpayer subsidies for fossil fuels while stripping them from wind and solar.

Nowhere has the political power of coal been more obvious than in presidential campaigns.