Only by advocating 'politically unrealistic' CO2 concentrations can runaway global warming be avoided. But what is politically realistic for humans is whollymunrelated to what is physically realistic for the planet.

If we are to save humanity and the planet from the worst mass extinction of all time, worse even than that at the end of the Permian, we must stop at two degrees.

You'd be forgiven for thinking that climate change means we'll have to sacrifice our creature comforts. But it doesn't have to be that way.

We humans, one species of animal amongst millions, have now become the de facto guardians of the planet's climate stability.

I am also sorry that I helped to start the anti-GM movement back in the mid 1990s, and that I thereby assisted in demonizing an important technological option which can be used to benefit the environment.

An outdated view still prevails that a low-carbon lifestyle requires immense personal suffering and sacrifice. In my view, nothing could be further from the truth. All the evidence shows that people who do not drive, do not fly on planes, do shop locally, do grow their own food, and do get to know other members of their community have a much higher quality of life than their compatriots who still persist in making the ultimate sacrifice of wasting their lives commuting to work in cars.

Only by advocating 'politically unrealistic' CO2 concentrations can runaway global warming be avoided. But what is politically realistic for humans is whollymunrelated to what is physically realistic for the planet.