“If we want to hold the 1.5 degrees [Celsius; 3.6 degrees Fahrenheit] line, which is the ambitious goal of the Paris agreement, we have maybe 300 billion tons left – more or less the budget of 10 years – if we do business as usual. If we want to hold the 2 degrees line, which is more realistic, we have another 20 to 30 years to go, but no more actually. So it’s a very tight budget.

It’s quite mind-boggling – for example, by 2030, we have to phase out the combustion engine. And we have to completely phase out the use of coal for producing power. By 2040 we will probably have to replace concrete and steel for construction by wood, clay and stone.

We are at the crossroads now: We either say: this thing is too big for us, this task cannot be done. [Then]

Interview: Schellnhuber: ‘Scientists have to take to the streets’ to counter climate denial [h/t to Dennis Ambler]

Heck, why not just go to 15C or 20C, and really get people worried? I’m sure there’s a model for that.

There’s also a model for this particular kind of doomsday thinking.

In case you missed the pun about 12, see this.