It's the biggest challenge humanity has ever faced, but we can keep global warming to within the "safe" boundary of 1.5°C. Here's how we do it

Woods Wheatcroft/Aurora Photos

“We have to do everything, and we have to do it immediately.” As a summary of the challenge facing humanity, those words are about as pithy as it gets. They come from Piers Forster, a professor of climate physics at the University of Leeds, UK, and a lead author on the latest report from the Intergovernmental Panel on Climate Change (IPCC). In case you missed it, it said we’re done for. Almost.

To give ourselves a better-than-evens chance of avoiding 1.5°C of global warming – the agreed threshold of irreversible, dangerous and possibly game-over climate change – we must hit peak greenhouse gas emissions as soon as possible, and then taper them down to net zero by 2050, give or take five years.

That’s doable – just. “It is not impossible,” says Heleen de Coninck, another IPCC lead author at Radboud University in the Netherlands. “We don’t need any fancy new technologies.”

But it will require “unprecedented rates of transformation”, according to the IPCC report. We must break our addiction to fossil fuels, meat, flying, reckless consumption in general, and above all confront the head-in-the-sand denial that has prevented us from making changes we knew we had to make yonks ago, but somehow kept telling ourselves weren’t necessary just yet.

So how can we do it? Think of it as a video game with seven levels of increasing difficulty – seven levels we must now play simultaneously.

There are many pathways in this giant, multidimensional, multiplayer game, although none is certain to lead to the outcome we want. …