Study shows threat fossil fuel plants pose to climate

Numerous environmental activists block the tracks of the coal transport railway in Rommerskirchen, Germany. Photo / AP

The world's existing power plants, industrial plants, buildings and cars are already numerous enough — and young enough — to commit the Earth to an unacceptable level of warming, according to new research published yesterday.

This fossil fuel infrastructure merely needs to continue operating over the course of its expected lifetime, and the world will emit more than 590 billion tonnes of carbon dioxide, more than enough to dash chances of limiting the Earth's warming to a rise of 1.5C.

And it gets worse: Proposals and plans are afoot for coal plants and other infrastructure that would add nearly 180b tonnes of emissions to that total. Some of these are now actually under construction. In other words, human societies would need not only to cancel all such pending projects but also timeout existing projects early, in order to bring emissions down adequately.

"1.5C carbon budgets allow for no new emitting infrastructure and require substantial changes to the lifetime or operation of already existing energy infrastructure," concludes the study in Nature by Dan Tong of the University of California at Irvine and colleagues from that institution, Tsinghua University in China, Stanford and the industry-monitoring group CoalSwarm.

The globe currently emits more than 32b tonnes of carbon dioxide annually from fossil fuel burning and cement manufacturing, based on 2017 figures from the Global Carbon Project. An additional roughly 4.5b tonnes are contributed through land use changes, most prominently deforestation. In total, humanity is pouring 37b tonnes of carbon dioxide into the atmosphere each year.

The most recent estimate of the so-called carbon budget is that since the beginning of 2018, we can only emit between 380 and 530b tonnes if we want to ensure a 50 to 66 per cent chance of limiting warming to 1.5C. That amounts to between 10 and 14 years at current emissions.

If there's good news, it's that current infrastructure does not irrevocably commit the Earth to 2C of warming, the study found. And we can still avoid higher levels of warming says Ken Caldeira, a professor at the Carnegie Institution for Science at Stanford and one of the study's authors.

"To me the optimistic take on it is that most of the emissions associated with the higher warming scenarios come from infrastructure that's yet to be built," he said. "So avoiding those outcomes are still within our control and it's largely a political and social decision ... I'm just hoping that nobody will be writing a decade in the future, 'Oh, we built enough infrastructure to go through 2 degrees, but we can still avoid 2.5'."