By Abby King

The Argument for Attribution Science in Climate Litigation:

Humans have manipulated the earth’s climate beyond its ecological limits. This manipulation has exacerbated natural climate change, leaving in its wake environmental and social destruction that jeopardizes the health and well-being of future generations (Atapattu, 2015, p. 1-3). The most recent report of the Intergovernmental Panel on Climate Change (IPCC) states that the number of people who are exposed to climate-related risks and susceptible to poverty may reach up to several hundred million by 2050 (Setzer, 2020, p. 14). The disastrous effect humans, specifically corporations from the Global North, have had on the environment is indisputable (Atapattu, 2015, p. 1-3). And oftentimes, the polluter that contributed to the extreme weather event or gradual detrimental change in living environment is not held accountable (Atapattu, 2015, p. 1-3). Instead, countries and peoples in the Global South bear the burden of pollution (Atapattu, 2015, p. 1-3). Attribution science can be used as a tool in climate litigation to help properly allocate responsibility to the corporate and government actors who caused the transboundary harm and provide a remedy by requiring the actors to finance the mitigation and adaption for other states (Burger, 2020).

Attribution science first collects data on extreme weather events that deviate from historical norms, then analyzes what the root cause of why they deviated and assesses the pain and suffering it brought to the people impacted (Burger, 2020). There are two different approaches to attribution science. Single-step attribution focuses on one link in the causal chain of anthropogenic climate change, and this is sometimes favored because it isolates extraneous variables, but this isolation fails to account for other possible causes (Burger, 2020). Multi-step attribution accounts for how multiple climate variables have changed in response to human activity. But with each additional link in the causal chain there is greater room for error, and it becomes more difficult to connect back to the catalyst (Burger, 2020).

Source, impact, and extreme event attribution are the three different ways attribution science can be measured (Burger, 2020). Source attribution identifies how government or corporations have contributed to climate change through greenhouse gas emissions. Impact attribution identifies how change in the climate impacts the natural and human system. And extreme event attribution shows how changes in the global climate system impact how catastrophic and frequent extreme weather events have become (Burger, 2020).

One of the biggest hurdles in attribution science is how to differentiate normal changes within the climate system and impacts on the system from anthropogenic sources. The International Panel on Climate Change (IPCC) addresses this hurdle by establishing liability by studying the physical impacts of extreme weather events like effects on lives, jobs, health, infrastructure, and economies. (IPCC AR5 WGII). Both the February and August IPCC reports substantiate attribution science, which helps legitimize the science in the eyes of the court. Fossil fuel industries do not challenge IPCC climate findings in court because of the experts’ part in the review process, and if attribution science becomes a mainstream way of collecting data, this could change the course of litigation efforts (Burger, 2020).

How to measure fault in attribution science:

Assigning fault for greenhouse gas emissions is difficult, because while a country in the Global South may be doing the actual emitting, it is a corporation from the Global North funding and sanctioning the emissions for these internationally traded goods (Setzer, 2020). The Global South then bears the burden of immediate negative environmental impact from the excess pollution causing health and safety issues while the Global North benefits by selling the finished products (Setzer, 2020). A way to account for this is dividing responsibility in different ways: by stage of economic development, global region, county, sector, company, and consumer (Burger, 2020).

National accountability encompasses territorial emissions of the country and consumption-based emissions that account for the emissions embodied in all the products that the country consumes (Burger, 2020). Corporate accountability is split between upstream and downstream entities. Upstream entities are like fossil fuel producers who create the energy necessary to make the product or good. Downstream entities are like the manufacturers and consumers, who are more closely tied to the good’s final product (Burger, 2020).

Attribution science is vulnerable to being misused and miscalculated to benefit mega-corporations and the Global North, similar to carbon-credits. The attribution of pollution designated to internationally traded goods should be fair. The UNFCCC reporting requirements currently allocate the emissions solely to the exporting jurisdiction, instead of where those goods are consumed. By changing to consumption-based emission reporting will allow countries to have a more accurately reflective emission reduction obligation within the Paris Agreement’s temperature goals and hold upstream and downstream entities more accountable (The Paris Agreement, Section II C; Wentz, 2023 p. 11).

While consumption-based emission reporting can account for current responsibility, attribution science also seeks to identify the states that bear the responsibility based on their historic emissions. Two-thirds of all industrially sourced carbon emissions between 1880-2010 can be traced to 90 large companies in the coal, oil, natural gas, and cement industries (Wentz, 2023, p. 11). Attribution science can be used retroactively to assign fault to these corporations and offers a tool for litigators in court.

Attribution science and climate litigation

By addressing historic and current allocation of blame to these polluters, attribution science can change the future of climate litigation. Climate litigation is defined as any piece of federal, state, tribal or local administrative or judicial litigation that directly and expressly raises an issue of fact or law regarding climate change, its causes, or impacts (Setzer, 2020, p. 3). Climate-change lawsuits used to be rare and typically only utilized by the U.S. or Global North. They have become much more common, but still U.S. based with 1,300 cases filed globally in 2019, and 1,000 of those filed in the U.S. (Setzer, 2020, p. 8).

In order to have a successful claim, the plaintiff needs to establish injury, defendant’s blame for said injury, and prove defendant’s knowledge of said harm (Burger, 2020). The expert knowledge required makes climate litigation expensive and often inaccessible for the countries and people who need remedy most. However, while there are significant capacity constraints for climate litigation in the Global South, cases are still growing in both quality and quantity especially in Brazil, Colombia, India, Indonesia, Pakistan, the Philippines, and South Africa (Setzer, 2020, p. 2).

The Global North and Global South have different approaches to climate litigation, which will change how attribution science can fold into each respective strategy. (Setzer, 2020, p. 9). The Global North tends to request direct regulatory action on climate change by governments. See Juliana v. United States, Friends of the Irish Environment v. Ireland, Urgenda Foundation v. The Netherlands (Setzer, 2020, p. 10). The Global South takes a more indirect route and instead focus on poor enforcement of existing planning and environmental legislation. See Earthlife Africa Johannesburg v. Minister of Environmental Affairs and Others (Setzer, 2020, p. 10-11). Attribution science will need to be applied against existing planning and environmental legislation in the Global South and can be used as evidence to advocate direct regulatory action in the Global North. Using single-step attribution for the Global South to isolate the legislation that is not being enforced could be helpful for using resources more efficiently, especially when looking at impact attribution to see how the natural environment has been changed as a result of the polluters. The Global North could use multi-step attribution by measuring source attribution to include more climate variables when litigating to hold more corporate up-stream entities responsible when asking for direct regulatory action.

The Global South is also able to challenge existing plans and legislation because a human rights framework is already in many countries in the Global South’s constitutions. Colonialism has played a large part of ravaging the Global South of their political, cultural, and physical resources (Setzer, 2020, p. 13).

Recommendation for the International Court of Justice Advisory Opinion:

Attribution science should be included in the International Court of Justice’s (ICJ) advisory opinion on climate change (Tigre, 2023). The ICJ releases advisory opinions that can guide courts as an expert legal body and will release their climate change opinion in late 2024 or early 2025 (Tigre, 2023). Legitimizing attribution science as a tool in climate litigation would offer plaintiffs more leverage in successfully allocating blame to corporate and state actors. The ultimate goal is to make attribution science part of customary international law – opinio juris.

The text of the advisory opinion should build off the Paris Agreement by reiterating the treaty’s findings and going one step beyond that to make attribution science a legitimate tool courts can turn to when assessing blame in climate litigation (Paris Agreement). The IPCC in its most recent assessment concluded that “there is new or stronger evidence for substantial and wide-ranging impacts of climate change” globally. IPCC AR5 WGII at 982. Climate attribution science is helpful in litigation, but also when interpreting the no harm principle, the polluter pays principle, common-but-differentiated-responsibilities, and the obligations of each state under the Paris Agreement. A way to hold the Global North accountable is by switching to a consumption-based emissions model under the Paris Agreement to hold the countries who are taking the most accountable under a common but differentiated responsibility framework. And, while no one country will be the but-for cause of a disaster, attribution science is a tool to divvy up the blame fairly, so the Global South does not need to bear the brunt of the human rights and environmental violations.

Bibliography:
IPCC, 2022: Climate Change 2022: Impacts, Adaptation, and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. Cambridge University Press, Cambridge, UK and New York, NY, USA, 3056 pp., doi:10.1017/9781009325844.
Paris Agreement to the United Nations Framework Convention on Climate Change, Dec. 12, 2015, T.I.A.S. No. 16-1104.
Maria Antonia Tigre & Jorge Alejandro Carrillo Bañuelos, The ICJ’s Advisory Opinion on Climate Change: What Happens Now?, Columbia Law School, Sabin Center for Climate Change Law, (2023).
Michael Burger, et. al., The Law and Science of Climate Change Attribution, Colombia Journal of Environmental Law, 2020.
Sumudu Atapattu and Carmen G. Gonzalez, The North-South Divide in International Environmental Law: Framing the Issues, 2015.
Wentz, J., Merner, D., Franta, B., Lehmen, A., & Frumhoff, P. C. (2023). Research priorities for climate litigation. Earth’s Future, 11, e2022EF002928. https://doi.org/10.1029/2022EF002928.