Legal implications of the climate-health crisis: A case study analysis of the role of public health in climate litigation

We found litigation which was reported using the term climate change, or where it was implied by the subject via reference to relevant social issues, biodiversity loss, environmental degradation, carbon emissions, economic/land/property loss, linked legal regulation, or linked corporate governance. Cases were also found where climate change was peripheral to the argu- ment such as where general environmental destruction was the primary concern, yet climate disruption was alluded to as a secondary consequence. We extracted consistent, basic, pre-defined data from the cases documents on plaintiff, defendant, legal precedent, decision, core argument, and court, to assess cases with an implicit concern for health. We performed a search in these case documents to quantify the number of times that the word health was explicitly used in this litigation. We used the case data to iden- tify climate litigation with a legal strategy, where the plaintiff relied on climate science and public health as part of a systematic challenge to a field of law. This resulted in 65 cases catego- rized as public health climate litigation, where public health was part of the litigation strategy. The primary sources for this research have been the respective case law databases of the Grantham Research Institute on Climate Change and the Environment [68], and the Sabin Center for Climate Change law [69]. We also searched ECOLEX: a data base operated by FAO, IUCN and UNEP, whose purpose is to “build capacity worldwide by providing the most com-

prehensive possible global source of information on environmental law and includes treaties, treaty decisions, legislation, and literature along with jurisprudence”. The primary databases are the most comprehensive, publicly available databases for researchers of case law in the field of Climate law. According to the methodology of the data- base provided by the Grantham Research Institute for Climate and the Environment: “The analysis covers all UN and UNFCCC parties, including the European Union, as well as a num- ber of countries, regions and territories that are not UN or UNFCCC members (e.g. Taiwan, Palestine and Western Sahara)” [70]. The focus of our research is on the role of public health in strategic climate litigation, build- ing upon the significant document pooling already contained in the chosen sources, including the translation of non-English language case documents. The databases of the Grantham Research Institute and the Sabin Center for Climate Change law are organized under a climate science agenda, with an interdisciplinary focus on climate change. Despite increasing literature on climate law, this is an emerging field, and there are limited data sources for such research. While these databases were considered relatively robust sources for the comprehensive identification of past litigation cases, it is notable that they have some limitations in their scope, as discussed in greater detail in the limitations section. Results Temporal trends The literature review yielded a total of 1641 cases of climate litigation filed between 1990 and

September 2020. As of November 2020, a total of 2069 Climate Laws and Policies were in force [71]. The numbers according to region are: (i) East Asia and Pacific– 391 (ii) Europe and Cen- tral Asia– 677 (iii) the EU– 41 (iv) Latin American and the Caribbean– 364 (v) Middle East and North Africa– 125 (vi) North America (including Canada)– 33 (vii) South Asia– 109 (viii) Sub Saharan Africa– 383 [72]. Of these 2069 Climate Laws and Policies, 1920 (93%) have been passed since 2000, and 1367 (66%) have been passed since 2010 [73]. The distribution of these cases by year is shown in Fig 1 which depicts a clear trend of increasing numbers of cases across time, with only 9 cases filed from 1990–99 and 836 cases filed from 2015–20. Not shown in Fig 1, the year the Paris Agreement came into force was piv- otal, with a sharp increase in cases after 2016. PLOS ONE Public health as a legal tool in climate litigation PLOS ONE | https://doi.org/10.1371/journal.pone.0268633 June 15, 2022 8 / 31