The Washington Post
Study: U.S. emissions linked to global GDP losses
The United States and China, the world’s two leading greenhouse gas emitters, are each responsible for more than $1.8 trillion of global income losses from 1990 to 2014, according to a new study that links the emissions in individual countries to the economic effects of climate change in others. The report may bolster the scientific basis for legal claims for losses tied to global warming.
The Dartmouth College study, published in the journal Climatic Change, linked one nation’s emissions of heat-trapping gases to losses and gains in the gross domestic product of 143 countries for which data is available. It found that five of the world’s leading emitters of greenhouse gases caused $6 trillion of global economic losses through warming caused by their emissions from 1990 to 2014. Economic losses caused by Russia, India and Brazil exceeds $500 billion over that period for each of those three emitter countries.
“This research provides an answer to the question of whether there is a scientific basis for climate liability claims. The answer is yes,” said Christopher Callahan, a doctoral candidate at Dartmouth and an author of the study, in a statement. “We have quantified each nation’s culpability for historical temperature-driven income changes in every other country.”
The United States, for example, inflicted $34 billion of economic losses on the Philippines during the 1990 to 2014 period, considering emissions generated from U.S. territory.
The researchers said U.S. emissions produced a 0.054-degree Celsius change in the global average temperatures in that period. This resulted in a 0.04-degree Celsius change in the average temperature in Indonesia over the same period, a change attributable only to emissions from the United States.
“This change may seem small, but because Indonesia is a warm, tropical country, increases in temperature are quite harmful to its economy,” Callahan said. “Every 1-degree increase in its local temperature reduces its economic growth by 1.6 percentage points.”
Putting these numbers together showed the United States reduced Indonesia’s economic growth by 0.065 percentage points each year in that same period. And, Callahan said, because Indonesia is a populous country with a large economy, even these small reductions in economic growth added up to large absolute number: a loss of $124 billion over the period.
The question of liability for climate change has been the subject of a growing number of lawsuits worldwide.
Cities and states have sued the global oil company Exxonmobil for not disclosing to investors the risks of climate damage. A variety of environmental groups took Shell to court in the Netherlands. And a Peruvian farmer is suing RWE, alleging that Germany’s largest utility, which scientists say has emitted 0.47 percent of the cumulative global industrial emissions of carbon and methane between 1751 and 2010, should have to pay its share to protect a small town in the Peruvian mountains.
Meanwhile, many developing countries have sought to get industrialized nations to pay for “loss and damages” they link to decades of emissions.
“For the first time, we have been able to show clear and statistically significant linkages between the emissions of specific countries and historical economic losses experienced by other countries,” Callahan said. “This is about the culpability of one country to another country, not the effect of overall global warming on a country.”
White House climate envoy John F. Kerry said at the close of the Glasgow climate summit that he understood the push for loss and damage payments, but that there was no spending mechanism.
The Dartmouth team believes its study “discredits the idea that climate mitigation is simply a ‘collective action problem,’ where no one country acting alone can have an effect on the impacts of global warming,” said Justin Mankin, an assistant professor of geography at Dartmouth and senior researcher on the study.
Other studies have relied on one or two parts of the three-step approach taken by the Dartmouth team.
“Scientists have previously described the historical economic effects of global warming, showing that climate change has benefited cooler, well-off countries and harmed warmer, less-well-off countries,” Callahan said. But, he said, they have not quantified the culpability of individual emitters. Another recent study quantified the effects that individual countries’ emissions can have on other countries’ temperatures but did not quantify the economic effects of these temperature changes.
“Our work can be seen as uniting these two disparate strains of work in a single integrated framework,” he said.