Estimates of how bad the situation is, of course, differ, but various assessments agree that the global economy is consuming resources at a rate equivalent to 1.3 to 1.5 times the earth’s capacity to supply them sustainably.

This is the week when according to the UN we will reach a population of 7 billion.

Fewer people consuming resources equals sustainability. Ever more people aspiring to say US levels of consumption equals misery. As Mr Micawber almost said.

Cat

Let's face it...........it was only 10,000 years ago that most of Britain was under a mile of ice and the entire country was uninhabitable. That was a pretty bad situation ! Yet it's pretty much the norm and inter-glacials the rarity.

But in those days it was feasible, if a bit of a PITA, to migrate ahead of the ice to tropical regions, because there were only a few hundred thousand people on earth.

Next time, the migrants will be met with nukes wielded by people saying get off my lawn.