Journalist, author, and speaker Gwynne Dyer lectures on climate change — the biggest crisis human beings have ever faced — and a possible way through it.

When you talk to the people at the sharp end of the climate business, there is an air of suppressed panic in many of the conversations. We are not going to get through this without taking a lot of casualties, if we get through it at all.

Every country in the world has pledged never to allow the rise in the average global temperature to exceed two degrees Celsius, but we are probably going to pass right through the two-degree limit. 450 parts per million of carbon dioxide in the atmosphere will give us +2C, and we are already at 400 ppm.