The worst case scenario sees the Amazon rainforest burning, huge amounts of methane being released by Siberian peat bogs and so on - by the time today's six year olds are 60, such a scenario would see global warming already out of control.

I wonder what sentences judges might hand down at future international criminal tribunals on those who will be partially but directly responsible for millions of deaths from starvation, famine, and disease in the decades ahead.

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

Once the 'portals of the future close - in Amazonia, Siberia or the Arctic - we will find ourselves powerless to affect the outcome of this dreadful tale.

I discovered science, and in the process I hope I became a better environmentalist.

Silent Summer - a never-ending heat wave, devoid of birdsong, insect hum, and all the weird and wonderful living noises that subconsciously keep us company.

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.