Limiting global warming is getting harder, analysis says

The gulf between the greenhouse gas emission reductions needed to limit global warming and what countries have actually achieved is four times as large as it was a decade ago, according to an analysis published March 4 (Nature 2020, DOI: 10.1038/d41586-020-00571-x).

Without serious policy change, the gap will continue to widen, according to the researchers who did the analysis. As it does, it will become more difficult to meet the 2015 Paris Agreement goal of limiting global average temperature rise to less than 2 °C over preindustrial levels by 2100.

For a decade, the United Nations has described the disparity between necessary reductions and what countries are in fact doing to meet international goals in an annual Emissions Gap Report. A group of researchers led by Niklas Höhne, a climate policy researcher at NewClimate Institute, decided to look at the decadelong trend in these reports, and the findings are stark.

“The gap has increased,” Höhne says. “It’s disappointing.”

Höhne attributes the lack of action to “the inertia of our societies.” Renewable energy and other solutions to reduce emissions are available, and their costs have dropped even more than experts expected just a few years ago. The world reached the Paris Agreement because the two biggest emitters, China and the US, worked together, Höhne says. But that cooperation has eroded, and those two countries are not reducing their emissions. Meanwhile, “other countries can point to big emissions from the US and China” to justify their own lack of action, Höhne says.

But he and his collaborators, who include policy researchers in India, China, Brazil, and the US, point to some bright spots. The UK has committed to becoming carbon neutral by 2050, and California has made a similar pledge for 2045. Höhne is also encouraged by the efforts of cities and even aviation and steel companies that have made similar goals.

“Even though the gap has increased, some actors are moving at the pace that’s necessary—and that’s a small but growing group,” he says.