What we are talking about is extended world war...People would move on a massive scale. Hundreds of millions, probably billions of people would have to move.

Climate change is a result of the greatest market failure the world has seen...We risk damages on a scale larger than the two world wars of the last century.

Failing to curb the impact of climate change could damage the global economy on the scale of the Great Depression or the world wars by spawning environmental devastation that could cost 5 to 20 percent of the world's annual gross domestic product.

Give up meat to save the planet.

How is it that, in the face of overwhelming scientific evidence, there are still some who would deny the dangers of climate change? Not surprisingly, the loudest voices are not scientific, and it is remarkable how many economists, lawyers, journalists and politicians set themselves up as experts on the science.

Greenhouse gas emissions: Ultimately, stabilisation - at whatever level - requires that annual emissions be brought down to more than 80% below current levels

Do politicians understand just how difficult it could be, just how devastating rises of 4C, 5C or 6C could be? I think, not yet