Two degrees Celsius: That’s the global temperature increment scientists say the world must stay beneath to avoid the worst effects of climate change. But according to a study published this week in the journal Nature Climate Change, the odds of us staying under this threshold are looking pretty grim.
The study, which looked at carbon use, population trends and the projected economic growth of 150 countries, forecast only a 5 percent chance that warming would be limited to 2 degrees above pre-industrial levels by the year 2100.
“We’re closer to the margin than we think,” lead author Adrian Raftery, a statistics professor at the University of Washington, told the Guardian this week. “If we want to avoid 2 degrees Celsius, we have very little time left. The public should be very concerned.”
Two degrees Celsius is the global temperature rise that the signatories of the Paris climate agreement have committed to staying under. They also set a loftier goal of 1.5 degrees Celsius ― but according to the new paper, there’s only a 1 percent chance of that happening.
Instead, the “likely range” of global temperature increase by 2100 is 2 to 4.9 degrees Celsius, the researchers concluded ― with a median rise of 3.2 degrees Celsius.
Despite the depressing findings, however, experts warned that giving up is not an option. Emissions could still significantly decline if there was, for instance, a substantial rise in renewable energy use or other “breakthrough technologies” ― factors that were not considered in the scientists’ calculations.
The study authors said they hope their research will remind people of the urgency to take action ― and to act immediately. “Even if the[ 2 degrees Celsius] target isn’t met, action is very important,” Raftery told the Guardian. “The more the temperature increases, the worse the impacts will be.”
The researchers also had a message for President Donald Trump, who shocked the world in June when he announced the United States’ withdrawal from the Paris accord.
The scientists said they did not adjust their calculations based on U.S. policy changes under Trump, but noted that his decision on the Paris pact would “certainly be a negative one.”
“I would remind the Trump administration something about real estate … It’s really hard to make money on real estate that’s under the ocean,” study coauthor and economist Dick Startz told Wired this week. “That’s where a lot of American real estate is going to be (notably in Florida) if we don’t change course.”