A stark new report from the world’s authorities on climate change warned that the planet is on the brink of failing at a broad effort to keep global warming to moderate levels. And while it is still possible to keep global warming at 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels, governments would have to take “rapid, far-reaching and unprecedented changes in all aspects of society.” Making the changes necessary to prevent the severe consequences of climate change would require a transformation of the global economy at a scale and speed that has “no documented historic precedent,” the report issued on Monday by the Intergovernmental Panel on Climate Change said. For now, the planet appears to be on track to reach that crucial threshold by as early as 2030.
The planet has already gotten two-thirds of the way to reaching the crucial level considering global temperatures have increased about one degree Celsius. “This is concerning because we know there are so many more problems if we exceed 1.5 degrees C global warming, including more heatwaves and hot summers, greater sea level rise, and, for many parts of the world, worse droughts and rainfall extremes,” Andrew King, a lecturer in climate science at the University of Melbourne, said in a statement.
The report is seen as particularly concerning because scientists conclude that some of the most severe effects of global warming — including worsening food shortages and wildfires — would be felt with a warming of 1.5 degrees Celsius above preindustrial levels. “Scientists might want to write in capital letters, ‘ACT NOW, IDIOTS,’ but they need to say that with facts and numbers,” Kaisa Kosonen, who was an observer at the negotiations from Greenpeace, said. “And they have.” Previous analyses had focused on estimating the effects of reaching two degrees Celsius above preindustrial levels. “It’s a line in the sand and what it says to our species is that this is the moment and we must act now,” said Debra Roberts, a co-chair of the working group on impacts. “This is the largest clarion bell from the science community and I hope it mobilises people and dents the mood of complacency.”
Working to avoid that 0.5-degree difference would have huge consequences for the world at large as it would help hundreds of millions fewer people be exposed to climate-related catastrophe and poverty. To prevent warming from reaching that threshold, greenhouse pollution would have to decrease by 45 percent from 2010 levels by 2030, and 100 percent by 2050. Although possible to transform the world economy in the few years necessary to avoid this increase, the authors of the study concede it is unlikely. After all, under President Donald Trump, the United States, which is the world’s second-largest greenhouse gas emitter behind China, is going the other direction as the commander in chief has vowed to increase the burning of coal.
“Frankly, we’ve delivered a message to the governments,” said Jim Skea, a co-chair of the IPCC panel and professor at Imperial College London. “It’s now their responsibility … to decide whether they can act on it.” Christiana Figueres, who was head of the U.N.’s climate body for six years, writes in the Guardian that the report makes clear the “determinants of whether we head for 2C or for 1.5C are mainly political; they are not technical or economic.”
Others, however, said they were skeptical that it was even realistic to consider the possibility of limiting warming to 1.5 degrees Celsius. “Even if it is technically possible, without aligning the technical, political and social aspects of feasibility, it is not going to happen,” added Glen Peters, research director of the Center for International Climate Research in Oslo. “To limit warming below 1.5 C, or 2 C for that matter, requires all countries and all sectors to act.” Appalachian State University environmental scientist Gregg Marland, who isn’t part of the U.N. panel, tells the Associated Press that the report is so unrealistic it’s akin to an academic exercise wondering what would happen if a frog had wings. “I just don’t see the possibility of doing the one and a half,” he said, noting that for now even limiting warming to two degrees Celsius seem unlikely.