An outdated view still prevails that a low-carbon lifestyle requires immense personal suffering and sacrifice.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.

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

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.

At 1.24 am on 26 April 1986 Chernobyl’s Unit 4 reactor exploded after staff disabled safety systems and performed an ill-advised experiment to check – ironically enough – the reactor’s safety.

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.

We no longer need to discuss whether or not it is safe – over a decade and a half with three trillion GM meals eaten there has never been a single substantiated case of harm. You are more likely to get hit by an asteroid than to get hurt by GM food.

If substantial methyl hydrate melt begins to occur in the Arctic Ocean basin, then the (carbon) accelerator will be jammed, and there will be nothing we can do to cut the speed of climate change.