The future economic costs of climate change will hit hardest in India and the United States, according to a new study published last week in the journal Nature Climate Change.
With the U.S. placing second on the scale of national climate impacts, “our analysis demonstrates that the argument that the primary beneficiaries of reductions in carbon dioxide emissions would be other countries is a total myth,” said lead author Kate Ricke of the University of San Diego’s School of Global Policy and Strategy and the Scripps Institution of Oceanography.
“It makes a lot of sense because the larger your economy is, the more you have to lose. Still, it’s surprising just how consistently the U.S. is one of the biggest losers, even when compared to other large economies.”
The study puts the social cost of carbon, based solely on impacts within U.S. borders, at nearly US$48 per tonne—nearly 20% higher than the $42 threshold adopted by the Obama administration for 2020, and orders of magnitude above the $3 per tonne the Trump administration put forward to justify rolling back Obama’s Clean Power Plan.
The study “estimates the future costs to each country based on all the ways climate change currently affects economies, such as higher health and energy costs and damage to property and agriculture,” InsideClimate News reports. “But the authors stress that it’s still a conservative estimate because it doesn’t capture longer-term effects that are still coming, including sea level rise that will put coastal cities at risk and ocean acidification that can damage fisheries.”
The study results “suggest the U.S. has been underestimating how much it benefits from reducing its greenhouse gas emissions, and that the country has far more to gain from international climate agreements than the Trump administration is willing to admit,” InsideClimate adds. “Some smaller countries are expected to lose significantly larger portions of their economies to climate change. But the authors found, after modeling hundreds of scenarios, that the U.S. consistently faces among the costliest damages.”
The results show the U.S. sustaining about 12% of the global damage from climate change, a bit less than its share of global greenhouse gas emissions. China’s estimated damages are just one-quarter the proportion of its global emissions, while India’s share of the damage is four times higher. “India is getting hit four times harder than it deserves to be based on its own emissions,” said atmospheric scientist and study co-author Ken Caldeira of the Carnegie Institution for Science.
Russia actually sees short-term benefits from a warming Siberia, while Canada and northern Europe would experience “low costs or even short-term benefits,” ICN states.
The results show most countries would have little incentive to cut greenhouse gas emissions based strictly on the economic impacts of climate change within their own borders.
“If all countries acted only on their own country-level social cost of carbon, the authors calculate that only about 5% of the global climate externality would be internalized,” InsideClimate writes. “But the longer-term effects are coming, and the study’s authors point out that economic damages will spill over as other nations struggle with global warming: trade disruptions will make it harder to import goods they depend on or to export their own, the risks of global economic turmoil and mass migration will rise, as will the potential for liability for damage caused by their years of high emissions.”