The Union of Concerned Scientists – 2017-09-09 00:37:49
Quantifying the Fossil Fuel Industry’s Climate Responsibility
Kathy Mulvey / The Union of Concerned Scientists
(September 8, 2017) — As Hurricane Harvey finally retreats from the Gulf Coast and Hurricane Irma threatens Florida’s coastline, communities are surveying the devastating damage done by these storms.
We know that human-caused climate change, including warmer temperatures and rising tides, can increase the power of storms like this and lead to more extreme weather and costlier impacts. And we know that global warming emissions from the fossil fuel industry have contributed to these changes in our climate.
After extreme weather events, communities face years of recovery and costly rebuilding. As the costs add up, it raises the question: Who should be held accountable for the costs being borne by communities across the United States?
New UCS-led research sheds light on that question.
We’ve known for decades that ExxonMobil, Chevron, and other fossil fuel companies peddled doubt and deception to confuse the public and policymakers about the climate impacts of their products. Even when they understood the harm they would cause, some major fossil fuel companies used disinformation to fight sensible climate policies.
Now, groundbreaking research from the Union of Concerned Scientists quantifies the responsibilities of ExxonMobil, Chevron, and other leading fossil fuel companies in simple terms: degrees and inches. For the first time, this peer-reviewed study clearly shows the contribution of major fossil fuel companies to global temperature increase and sea level rise. These findings can inform discourse regarding share of responsibilities.
Share this new cutting-edge research on Twitter and Facebook, and keep the pressure on fossil fuel companies as we work to hold them accountable for their role in climate change.
Kathy Mulvey is the Climate Accountability Campaign Manager for the Union of Concerned Scientists
Introduction
The question of responsibility for climate change is central to public and policy discourse over actions to curb greenhouse gas emissions and limit adverse impacts. The United Nations Framework Convention on Climate Change (UNFCCC) established the principle of “common but differentiated responsibilities” among nations, signaling the recognition that nations that had produced the larger share of historical emissions bore a greater responsibility for avoiding “dangerous anthropogenic interference with the climate” (UNFCCC 1992; UNFCCC 1998).
Reflecting this principle, the Paris Agreement establishes common commitments, for example to global net-zero greenhouse gas emissions in the second half of this century, while allowing flexibility in mitigation efforts to accommodate different national capacities and circumstances (United Nations 2015).
Considerable research has been devoted to assessing how national contributions to greenhouse gas emissions and climate change might be quantified according to differing allocation schemes of responsibility and combinations of anthropogenic climate forcers (UNFCCC 1997; Prather et al. 2009; Höhne et al. 2011; Wei et al. 2012; den Elzen et al. 2013; Matthews et al. 2014; Ward and Mahowald 2014).
Key factors affecting the relative contribution of nations to emissions and global mean surface temperature (GMST) increase include the emissions dates, and whether land-use change and forestry, non-CO2 gases, and aerosols are included or excluded (Prather et al. 2009; Höhne et al. 2011; den Elzen et al. 2013; Matthews et al. 2014).
Outside of the domain of the UNFCCC, broader societal discussions have begun to consider the climate responsibilities of non-state actors. These include individual high emitters regardless of nationality (Chakravarty et al. 2009) and high-emitting industries regardless of where they are incorporated (Allen and Lord 2004). T
hey also include the major multinational fossil energy companies at the base of the carbon supply chain, who to date have no responsibility from marketed products under existing policy regimes, but whose prospective responsibilities are receiving growing attention in scholarly, policy, institutional investment, legal, and public spheres (Leone 2012; Lubber 2012; Frumhoff et al. 2015; van Renssen 2016).
Attention to the responsibilities of fossil fuel producers is supported by recent research by Heede (2014), who found that nearly two-thirds of all industrial carbon dioxide (CO2) and methane (CH4) emissions can be traced to the products of a small number of major industrial carbon producers; 83 producers of coal, oil, natural gas, and 7 cement manufacturers. While recent investigations have addressed the question of how national responsibilities might be shared between producers and consumers of carbon-intensive products (Davis and Caldeira 2010; Peters et al. 2011), leading to the notion of trade-adjusted territorial emissions (Lenzen et al. 2007; Davis et al. 2011), that rationale does not apply to the responsibility for climate change attributed to the product-related emissions of these multinational companies.
Here, we extend Heede’s (2014) research to analyze the contribution of emissions traced to these major carbon producers to the rise in atmospheric concentrations of CO2 and CH4, GMST, and global sea level (GSL).
A benefit of the simple climate model approach is the ability to explore the emissions traced to major carbon producers in a way that is consistent with major climate- and impact-relevant Earth processes.
Since annual carbon emissions partition between the main carbon reservoirs — ocean, terrestrial, and atmosphere — a climate model can assess the fraction of CO2 remaining in the atmosphere while keeping track of the CH4 lifetime in the atmosphere and the resulting change in GMST.
Study of Earth processes over millennia demonstrates that both the land ice volume and ocean volume respond to global mean surface temperature (IPCC 2013). Once we have changes in GMST, we use the model to calculate changes in GSL (Kopp et al. 2016).
Two time periods were investigated for removing annual emissions traced to major carbon producers. The first, 1880–2010, represents the historical period with sufficient data available.
The second, 1980–2010, follows the publication of the US National Research Council report on carbon dioxide and climate and represents the period of growing awareness in the scientific, fossil energy industry, and policy communities of climate change risks associated with anthropogenic carbon emissions (NRC 1979; Frumhoff et al. 2015; Banerjee 2015).
The Rise in Global Atmospheric CO2, Surface Temperature,
And Sea Level from Emissions Traced to Major Carbon Producers
B. Ekwurzel, J. Boneham, M. W. Dalton, R. Heede, R. J. Mera, M. R. Allen, P. C. Frumhoff / Springer
(September 7, 2017) — Researchers have quantified the contributions of industrialized and developing nations’ historical emissions to global surface temperature rise. Recent findings that nearly two-thirds of total industrial CO2 and CH4 emissions can be traced to 90 major industrial carbon producers have drawn attention to their potential climate responsibilities.
Here, we use a simple climate model to quantify the contribution of historical (1880–2010) and recent (1980–2010) emissions traced to these producers to the historical rise in global atmospheric CO2, surface temperature, and sea level.
Emissions traced to these 90 carbon producers contributed ∼57% of the observed rise in atmospheric CO2, ∼42–50% of the rise in global mean surface temperature (GMST), and ∼26–32% of global sea level (GSL) rise over the historical period and ∼43% (atmospheric CO2), ∼29–35% (GMST), and ∼11–14% (GSL) since 1980 (based on best-estimate parameters and accounting for uncertainty arising from the lack of data on aerosol forcings traced to producers).
Emissions traced to seven investor-owned and seven majority state-owned carbon producers were consistently among the top 20 largest individual company contributors to each global impact across both time periods.
This study lays the groundwork for tracing emissions sourced from industrial carbon producers to specific climate impacts and furthers scientific and policy consideration of their historical responsibilities for climate change.
* A Springboard Commentary to this paper is available at doi:10.1007/s10584-017-2042-9.
* Electronic supplementary material
The online version of this article (doi:10.1007/s10584-017-1978-0) contains supplementary material, which is available to authorized users.
Posted in accordance with Title 17, Section 107, US Code, for noncommercial, educational purposes.
