Catalyst Fall 2017
Ideas in Action

Who’s Responsible for Climate Damages? The Latest Science Offers Some Insights

Brenda Ekwurzel

Brenda Ekwurzel (second from left), UCS director of climate science and senior climate scientist, participates in a September 2017 panel discussion about efforts to hold fossil fuel companies accountable for climate change impacts. The event was part of the ninth annual New York City Climate Week, coinciding with the annual United Nations General Assembly meeting.
Photo: Ben Goloff/UCS

By Seth Shulman

As estimates of the damage from recent hurricanes and wildfires in the United States now run into the hundreds of billions of dollars and coastal communities confront the need for mitigation projects to address sea level rise, more people are recognizing the burden climate change poses to taxpayers. In New York City alone, officials estimate that climate-related adaptation measures will cost more than $19 billion. Globally, cost projections are astronomical: the UN Environment Programme calculates that climate adaptation will cost developing countries $140 billion to $300 billion per year in 2030.

Given the scale of these costs, many are also asking what responsibility the major fossil fuel companies should bear—especially given the fact that internal company documents show they have known for decades about the harm their products were causing to the climate and continued to spend millions misleading the public and blocking climate action.

A pathbreaking new peer-reviewed study published in the journal Climatic Change by a team including climate scientists from the Union of Concerned Scientists sheds new light on fossil fuel producers’ liability. The authors have succeeded in tracing specific climate damages to the products sold by individual companies such as Chevron and ExxonMobil.

Brenda Ekwurzel, the study’s lead author and climate science director at UCS, explains, “We’ve known for a long time that fossil fuels are the largest contributor to climate change. What’s new here is that we’ve determined just how much specific companies’ products have caused the earth to warm and the seas to rise.”

Pinpointing Companies’ Impacts

The team looked at the largest oil, gas, and coal producers and cement manufacturers and used sophisticated computer analysis to quantify the amount of sea level rise and global temperature increase attributable to carbon dioxide and methane emitted during the extraction, production, and use of these companies’ products. The findings are striking. According to the study:

  • Emissions traced to the 90 largest carbon producers contributed nearly 50 percent of the rise in global average temperature and around 30 percent of global sea level rise since 1880.
  • Emissions traced to the 50 investor-owned carbon producers (including BP, Chevron, ConocoPhillips, ExxonMobil, Peabody, Shell, and Total) contributed around 16 percent of the global average temperature increase from 1880 to 2010, and around 11 percent of global sea level rise over that period. 
  • Emissions traced to these same 50 companies from just 1980 to 2010—the period in which fossil fuel companies were aware their products were causing global warming—contributed around 10 percent of the global average temperature increase and roughly 4 percent of global sea level rise.

Implications for the Courtroom

This study and others like it, part of an emerging field called climate attribution science, offer a powerful new tool that could help courts resolve the vexing problem of how to apportion responsibility for damages caused by climate change—potentially even damages sustained in an extreme weather event. For example, after Hurricane Sandy slammed into the East Coast in 2012, scientists determined that climate-driven sea level rise magnified Sandy’s flood damage to property in New York City alone by $2 billion—more than $230 per New Yorker. This latest research could help pinpoint a particular company’s share of that damage.

As we go to press, five California communities have filed lawsuits against fossil fuel companies. Most recently, San Francisco and Oakland have each sued five major fossil fuel companies for climate damages incurred on their cities. In another lawsuit already under way, three other California communities—Marin and San Mateo Counties and the city of Imperial Beach—are suing 37 oil, gas, and coal companies for climate-related damages to public property such as beaches and parks, and the possibility that some residents of these communities will lose their property and be displaced. The communities are seeking not only recompense for costs already incurred and anticipated costs to address the ongoing threat, but also a portion of fossil fuel production profits and punitive damages for the alleged wrongdoing.

A decision on this case is years away, and it is far too early to predict how it might unfold. But it is easy to see how climate scientists’ growing ability to apportion responsibility for climate damages could aid such claims. For now, with help from UCS scientists, these analyses are sparking a long-overdue public conversation about the legal responsibility of fossil fuel companies for the damage they knew their products were causing.