The Dartmouth College study found that just five of the world’s top emitters of planet-warming gases — the United States, China, Russia, India, and Brazil — caused around a $6 trillion loss in gross domestic product from 1990 to 2014, adjusted for 2010 dollars, or about 11% of the total global GDP.
“Before our work we had a pretty good idea of the economic effect of global warming. The problem is, that is not sufficient to provide an understanding of how culpable individual actors are,” said Christopher Callahan, a PhD candidate at Dartmouth College and co – author of the study.
Callahan said the new work puts “numbers to it, drawing out specifically what [a country’s] contribution has been.”
US Climate Envoy John Kerry’s office did not respond to CNN’s request for comment on the study. CNN has also reached out to China’s Ministry of Ecology and Environment for comment.
“I think it could make a splash ahead of COP27,” said Taylor Dimsdale, the program director for risk and resilience at the international climate think tank E3G. “Any discussion about responsibility is harder if you don’t have this kind of a model. Ultimately, these are political decisions.”
The damage is done
The countries most responsible for the harm to poorer economies tend to be those that have burned the most fossil fuel and emitted the most planet-warming gas, the study shows. The US and China were far and away the largest emitters, according to the report, followed by Russia, India, and Brazil. (The EU is typically near the top of the global emitters list, but the study’s authors divided the EU up into single countries, rather than calculating it as a bloc.)
The countries that have been hurt the most by the world’s largest economies are predominantly in the Southern Hemisphere, the study shows, where the average temperature was already hot even before the climate crisis.
“One of the challenges is the abstraction that global warming presents. What is increasingly clear is that those impacts are not felt equally across the world,” said Justin Mankin, an assistant professor of geography at Dartmouth and a co-author of the study.
Bangladesh, for instance, is a low-elevation coastal country on the front lines of rising sea levels and the flooding that comes with it. It has also suffered from deadly extreme heat and humidity.
The study points to the US and China as the top climate sources of the country’s economic harm. The US is responsible for $14.1 billion of Bangladesh’s economic losses from 1990-2014, while China is responsible for $13.6 billion, its data shows.
Mankin said many countries are in the same boat as Bangladesh, and you can “throw a dart at the map” and hit any country in the tropics to find one with a similar plight.
Things aren’t necessarily the same further north.
For instance, the study authors found that the economies in colder regions — like Canada, Russia and Scandanavian countries — have benefited from global warming to a certain extent. Warming temperatures have extended growing periods for crops and opened new shipping channels in previously frozen parts of the Arctic.
Solutions, or litigation?
But loss and damage has been a bridge too far at past summits.
Having a rich set of data to show how much poorer nations’ economies have been harmed could increase the pressure on richer nations at this year’s summit, experts told CNN.
“I do think that moves things along in providing this drumbeat that’s becoming difficult to ignore if you’re a decision maker in a rich country,” Dimsdale said.
Others told CNN that conversations have moved away from who exactly is responsible for the crisis and towards what should be done to solve it. Pointing fingers at specific countries and demanding reparations may not advance the conversation, one expert said.
“It’s the advanced and industrialized world that’s scared about this liability and compensation angle,” Nisha Krishnan, the climate resilience lead at the World Resources Institute Africa, told CNN. “Developing countries and small island nations can’t do this by themselves; they need the world to move with them. They’re very well aware that any sort of conversation about liability isn’t helpful.”
The data could be used in court to show a link between one country’s emissions and another’s economic losses, but any such lawsuit would likely be very drawn out and complicated, said Michael Burger, the executive director of the Sabin Center for Climate Change Law at Columbia University.
“In an event a country is able to clear the jurisdictional and legal hurdles of a transnational lawsuit, this would provide one potential methodology for allocating damage or allocating responsibility in collecting damages,” Burger said. “In actual litigation, the methodologies will be challenged, there will be competing views, there will be a battle of the experts, and every aspect of the study will be tested.”
Still, Burger said the Dartmouth study is “quite compelling.”
“I think it has the potential to attract a lot of attention,” he said.