Climatic Change
tracing emissions sourced from industrial carbon producers to specific climate impacts and
furthers scientific and policy consideration of their historical responsibilities for climate change.
1 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 Bcommon
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
Bdangerous 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). They 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