Biggest Firms on Earth Leave $28T Climate Tab in Their Wake

The world's biggest corporations have caused $28 trillion in climate damage over the years, estimates a new study, part of an effort to make it easier for people and governments to hold companies financially accountable, as the tobacco giants have been. A Dartmouth College research team came up with the estimated pollution caused by 111 companies, with more than half of the total dollar figure coming from 10 fossil fuel providers: Saudi Aramco, Gazprom, Chevron, ExxonMobil, BP, Shell, National Iranian Oil Co., Pemex, Coal India, and the British Coal Corporation. For comparison, $28 trillion is a shade less than the sum of all goods and services produced in the United States last year, per the AP.

At the top of the list, Saudi Aramco and Gazprom have each caused a bit more than $2 trillion in heat damage over the decades, the team calculated in a study published in Wednesday's Nature journal. The researchers figured that every 1% of greenhouse gas put into the atmosphere since 1990 has caused $502 billion in damage from heat alone, which doesn't include the costs incurred by other extreme weather such as hurricanes, droughts, and floods. The study is an attempt to determine "the causal linkages that underlie many of these theories of accountability," says its lead author, Christopher Callahan, now an Earth systems scientist at Stanford.

People talk about making polluters pay, and sometimes even take them to court or pass laws meant to rein them in. The research firm Zero Carbon Analytics counts 68 lawsuits filed globally on climate change damage, with more than half of them in the US. "Everybody's asking the same question: What can we actually claim about who has caused this?" said Dartmouth climate scientist Justin Mankin, co-author of the study. "And that really comes down to a thermodynamic question of: Can we trace climate hazards and/or their damages back to particular emitters?" The answer is yes, per Callahan and Mankin. Shell declined to comment. Aramco, Gazprom, Chevron, ExxonMobil, and BP didn't respond to requests for comment. It's not clear if the other listed firms are aware of the study. More here.

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