Missing climate goals could cost the world $20 trillion

There are trillions of reasons for the world to prevent temperatures from rising more than 1.5 ˚C, the aspirational target laid out in the Paris climate agreement, according to a new study.

The findings: If nations took the necessary actions to meet that goal, rather than the increasingly discussed 2 ˚C objective, there’s a 60 percent chance it would save the world more than $20 trillion, according to new work published today in Nature by scientists at Stanford. 

That figure is far higher than what most experts think it will cost to cut emissions enough to achieve the 1.5 ˚ target. Indeed, one study put the price tag in the hundreds of billions of dollars. If temperatures rise by 3 ˚C, it will knock out an additional 5 percent of GDP. That’s the entire planet’s GDP.

Why? The odds of catastrophic weather events increase sharply as temperatures rise, according to an earlier study led by Noah Diffenbaugh, who’s also a coauthor on the research out today. Reduced agricultural yields and new adaptations, like higher sea walls, also take their toll. 

Who benefits the most? Forecasting the economic effects of climate change decades into the future is a notoriously difficult task. But lead author Marshall Burke told MIT Technology Review in an e-mail that the major efforts to make such predictions have consistently concluded that “the benefits outweigh the costs” and that “poorer places will disproportionately benefit.”

Bottom line: Unfortunately, given the levels of greenhouse gases already emitted and the current political climate, a growing number of researchers believe it’s now all but inevitable that the world won’t cut emissions fast enough to avoid 2 ˚C of warming, much less 1.5 ˚C.