US Liable for $2 Trillion in Damage to Global Economy via Climate Change-Driven Pollution - Study

Published in the journal Climatic Change, the research describes how the planet’s warming climate, driven to higher temperatures by industrial gasses that trap sunlight, has caused one disaster after another, many of which have occurred in the world’s poorer and less industrialized nations.

“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,” said Christopher Callahan, the study’s lead author, in a news release. “This is about the culpability of one country to another country, not the effect of overall global warming on a country.”

The researchers looked at a 25-year period from 1990 until 2014 and the heat waves, crop failures, droughts, and flooding judged to have been made worse by climate change. That was no easy task, since there are no new natural disasters caused by climate change, just exacerbated ones. According to a Dartmouth news release, the scientists “combined historical data with climate models in an integrated framework to quantify each nation’s culpability for historical temperature-driven income changes in every other country.”

“The study sampled 2 million possible values for each country-to-country interaction. In total, 11 trillion values were calculated on a supercomputer operated by Dartmouth’s Research Information, Technology and Consulting,” the release explained.

However, they didn’t just tally up the US’ impact: they called out the five nations that emit the most greenhouse gasses, which include carbon dioxide, nitrogen oxide, and methane: in addition to the US, that’s China, Russia, Brazil, and India. Together, they’ve caused an estimated $6 trillion in damage to other nations’ economies, with the US bearing the most responsibility, having been an industrial nation for nearly two centuries. In the time frame encompassed by the study, that amounts to about 11% of annual gross domestic product for the planet.

Judged by raw carbon output, China is the world’s worst offender. However, with 1.4 billion people, or 17% of humanity within its borders, Beijing has argued that carbon emissions per capita is a fairer way to judge a country’s impact on global warming. By that metric, the US, with one-quarter the population of China, is twice as pollutive as the East Asian socialist republic. In addition, China’s industrialization only began in the second half of the 20th century, and only really began to accelerate in the last two decades of it.

According to the World Bank, US carbon emissions per capita were at 14.7 metric tons per American citizen in 2019, the most recent year for which there is data. That is the 11th-highest in the world, with Australia, Canada, Saudi Arabia, and a handful of small oil-producing nations ahead of the US. China ranks at 28th, with 7.6 metric tons of carbon emitted per person in 2019.

“Greenhouse gasses emitted in one country cause warming in another, and that warming can depress economic growth,” said Justin Mankin, an assistant professor of geography at Dartmouth and senior researcher of the study. “This research provides legally valuable estimates of the financial damages individual nations have suffered due to other countries’ climate-changing activities.”

A global climate summit in April 2021 saw nations around the globe pledge steep cuts to their carbon emissions over the next several decades, with the aim of reaching “carbon neutrality.” Without action, greenhouse gasses will continue to drive the Earth’s surface temperature higher, destabilizing the weather systems that make agriculture and aquaculture possible, and even more dangerously, causing glaciers and the polar ice caps to melt, which will cause the world’s seas to rise.

A 2021 study published in Nature Communications found that at least 410 million people live in areas threatened by rising ocean levels, living in regions that would be reclaimed by the sea if global sea levels rose by one meter, as they are projected to do by the year 2100.