A rise of 5C would be a temperature the world has not seen for 30 to 50 million years. We've been around only 100,000 years as human beings. We don't know what that's like.

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.

I think that once people understand the great risks that climate change poses, they will naturally want to choose products and services that cause little or no emissions of greenhouse gases, which means 'low-carbon consumption.' This will apply across the board, including electricity, heating, transport and food.

As an undergraduate, I did maths and physics. That doesn't make me a scientist. So I try to read and understand and talk to scientists.

Give up meat to save the planet.

The basic scientific conclusions on climate change are very robust and for good reason. The greenhouse effect is simple science: greenhouse gases trap heat, and humans are emitting ever more greenhouse gases.

A rise of 5C would be a temperature the world has not seen for 30 to 50 million years. We've been around only 100,000 years as human beings. We don't know what that's like.