It is five minutes to midnight on climate change. We will have to alter our trajectory very quickly if we wish to have a good chance of limiting the global average temperature rise to less than 1.5C above pre-industrial levels. That was a goal of the Paris agreement of 2015. Achieving it means drastic reductions in emissions from now. This is very unlikely to happen. That is no longer because it is technically impossible. It is because it is politically painful.
We are instead set on running an irreversible bet on our ability to manage the consequences of a far bigger rise even than 2C. Our progeny will see this as a crime. The latest report from the Intergovernmental Panel on Climate Change is on the implications of warming of just 1.5C and also on the means by which that might be achieved. It reads like a reductio ad absurdum — a demonstration of the implausibility of its premise. But it makes plain, too, the risks the world runs if this limit is ignored: life will survive, but not life as we know it.
Underlying this report is the idea of the Anthropocene — an era in which human activity has become a dominant influence on the planet. The report notes that the rise in global concentrations of carbon dioxide is 20 parts per million per decade. This is up to 10 times faster than any sustained rise in CO2 in the past 800,000 years. The previous epoch with similar CO2 concentrations to today’s was the Pliocene, 3m-3.3m years ago. We are the shapers of the planet now. This ought to transform how we think. Unfortunately, it has not.