Tracing Who’s Responsible for Temperature Increase and Sea Level Rise (2017)
The impacts of global warming are here and they are costly. Sea level rise floods towns and erodes shorelines. Frequent and intense heatwaves threaten our workers’ health and damage our infrastructure. Extreme weather ruins our crops and corrodes businesses, factories and homes. In New York City alone, officials estimate that it will cost $19.5 billion dollars to prepare the city for sea level rise. And globally, climate adaptation costs are staggering.
Will top fossil fuel producers help shoulder the costs? They should.
As early as 1977, investor-owned fossil fuel companies knew their business was risky—that the use of their products released dangerous amounts of carbon dioxide and methane emissions that could destabilize our climate.
These companies could have taken steps to reduce the risks. Instead, they chose to misinform the public and their investors, block action to limit carbon emissions and carried on with business as usual.
But, we now have the science to determine how much the emissions related to fossil products have contributed to global temperature rise and sea lever rise.
A peer-reviewed study, authored by Brenda Ekwurzel, James Boneham, Mike Dalton, Rick Heede, Roberto Mera, Myles Allen and Peter Frumhoff and published in Climatic Change, analyzed and quantified the climate change impacts of carbon dioxide and methane emissions traced to each company for two time-periods: 1880 to 2010 and 1980 to 2010.
Emissions traced to the largest 90 carbon producers contributed:
- 57% of the observed rise in atmospheric carbon dioxide since 1880.
- Nearly 50% of the rise in global average temperature since 1880.
- About 30% of global sea level rise relative to 1880 levels.
Emissions traced to 50 investor-owned carbon producers, including BP, Chevron, ConocoPhillips, ExxonMobil, Peabody, Shell and Total, were responsible for:
- roughly 16 percent of the global average temperature increase from 1880 to 2010,
- and around 11 percent of the global sea level rise during the same time frame.
Emissions traced to the same 50 companies from 1980 to 2010, a time when fossil fuel companies were aware their products were causing global warming, contributed:
- approximately 10 percent of the global average temperature increase
- and about 4 percent sea level rise since 1980.
Climate responsibility: Paying a fair share
In the United States, taxpayers are footing the bill for climate damages, such as the devastation from hurricane Sandy in 2012 or the California drought that resulted in a $3 billion cost to the agricultural sector in 2015.
Fierce policy debates about responsibility for climate mitigation and adaptation have long focused on the “common but differentiated responsibilities” of nations, the framework used for the Paris climate negotiations.
Increasingly, attention has turned to non-state actors, particularly fossil fuel producers: they knew about the risks of their business, and they chose to misinform investors and the public about those risks.
“Companies knowingly violated the most basic moral principle of 'do no harm,' and now they must remedy the harm they caused by paying damages and their proportion of adaptation costs," argues Henry Shue, professor of politics and international relations at the University of Oxford and author of a commentary on the ethical implications of the Ekwurzel et al. paper.
Building a case for responsibility
The study builds on landmark research published in 2014 by Richard Heede, of the Climate Accountability Institute. Heede’s initial research quantified the carbon dioxide and methane emissions resulting from burning the products of the 90 largest carbon producers.
Ekwurzel and her co-authors used Heede’s data on company emissions in a climate model that captures how these emissions are incorporated into the Earth’s carbon cycle.
The study used emissions data on the 90 carbon producers in a simple, well-established climate model that captures how carbon dioxide and methane emitted into the Earth’s atmosphere lead to the trapping of heat and drive increases in global surface temperature and sea level. Using this model, they were able to quantify the results of including or excluding different natural and human contributions to climate change—including the very specific contributions of emissions attributed to these companies’ products.