On the 10th of November 2020, as doctoral students of the Doktoratskolleg Climate Change, we met Roda Verheyen. As a partner at the Hamburg’s law firm “Gunther & Partner”, and earlier as a scholar, Ms. Verheyen has been dealing with climate law for years. With her firm, she has filed four groundbreaking cases: one against Germany’s largest electricity producer (RWE), two cases against the German government, respectively on behalf of a group of family farmers and climate activists, and one against the European institutions. All of these climate lawsuits have acquired popularity for their innovative, creative and ambitious character.
In the DK Climate Change, we look into climate litigation with an interdisciplinary lens, as we try to bring the philosophical, scientific and legal perspectives into one picture. In the last one and a half years, we have formed a working group on Attribution with the intention, among others, of investigating the implications of attribution science for climate cases. The time working together has brought us to engage with deep interdisciplinary questions about how relevant concepts are defined in different disciplines (e.g. loss and damage), how we frame questions, and how scientific uncertainties are approached.
The webinar was an opportunity for us to understand how such questions are dealt with in practice. Indeed, while working on interdisciplinarity can be felt as a burdensome privilege by a scholar, for a legal practitioner working on climate change, to look into science is rather a necessity. Among the insights given by Ms. Verheyen, I want to emphasize three points which I found particularly important.
Climate science plays an increasing role in climate lawsuits
Climate science and the science of attribution have played an important role since the beginning of climate litigation. [i]
However, climate litigation has recently been profiting from an evolved scientific context where, to start with, scientists have reached a robust consensus on the causal relationship between GHG emissions and climate change. The result of this trend can be seen in the open attitude with which Courts have been recognizing the central role of climate science. In Urgenda (2015), the Dutch District Court of den Haag conceded that “climate science can, on the basis of international law and consensus, define the State’s duty to protect.” In Juliana (2016), Oregon’s District Judge Aiken noted that “climate science is constantly evolving”, and that, as a result, a previous judgement dating back to more than five years before, could not be interpreted so as “to forever close the courthouse doors to climate change claims.” Finally, in a few recent trials, judges have asked to be informed about the state of the art in climate science. Most recently, the Brazilian Supreme Court held a public hearing where 66 experts, including scientists and researchers, were heard. Barroso, the presiding judge, expressed his intention to factually understand the state of Brazil’s policies, and repeatedly referred to the need to deal with the facts, without “creating an imaginary and parallel reality.”[ii]
Each case is unique
While climate science plays an increasingly important role in climate litigation, assessing its influence is challenging for at least two reasons. First, each case is a story of its own. Proving to belong to a group which is vulnerable to climate change is not the same in Germany as in Pakistan, not only because of the different levels of geographical exposure, but also due to the existence of different legal requirements. Secondly, science evolves and consequently, lawyers adapt their arguments and strategies.
This evolving trend can be easily noticed, by observing how evidentiary arguments vary in similar cases. As an example, Ms. Verheyen mentioned two climate cases she represented: Carvalho v. EU and Neubauer v. Germany. The legal core of the two claims is almost identical: climate policies are insufficient to achieve the Paris Agreement objectives and, as such, they violate the fundamental rights of the claimants.[iii] In the two cases, climate science entered into play to resolve the following question: what obligations does human rights law concretely imply for States and public actors?
While in Carvalho (2015) the applicants claimed that the EU, by pursuing its policies, was likely to overshoot its carbon budget share, the Neubauer lawsuit (2020) illustrated that the government’s line of action was incompatible with the pathways to keep the temperature increase below 1.5° (see figure below). The emphasis on the carbon budget models, still controversial due to their lack of robustness, was replaced, in the most recent lawsuit, with a focus on the alarming projections conveyed in the IPCC Special Report on 1.5° (2018). More in detail, the “pathway to follow” according to the claim, was obtained from the average of the various emissions paths assessed in the 2018 Report. As pointed out by Ms. Verheyen, the reason for such difference lied in the availability of different evidence at the time of the filing of the respective lawsuits.
Legal creativity can make up for scientific uncertainty
Climate science and particularly attribution, despite their increasing accuracy, often cannot fit within legal standards, unless they are creatively interpreted.
In cases where plaintiffs ask for a policy change, attribution science is still necessary to prove standing.[iv] Moreover, standing requirements vary from country to country. Under German law, the applicants need to prove that they are “directly and currently concerned in their basic rights”.
In the Neubauer case, the plaintiffs – a group of young climate activists – claimed that the government’s inaction had infringed their right to life and physical integrity, occupational freedom and dignity. Although particularised evidence was provided, showing that the plaintiffs’ health conditions and work opportunities had been affected by climate change, the lawyers were well aware that such arguments could be considered as insufficient, based on a strict interpretation of the law.
In this frame, the inclusion of the right to dignity was meant to prevent the risk that the complaint would be rejected on standing grounds. As formulated in the claim, the principle of human dignity requires the State “not to destroy the foundations of the self-development of others and the preservation of the conditions of existence of future generations.” The dignity argument, increasingly present in climate litigation, is grounded on an idea which can be found in other complaints: that the preservation of the climate is at the root of human life and society. In this sense, Judge Aiken’s opinion in the Juliana case is paradigmatic, namely, where she stated that “a stable climate system is quite literally the foundation “of society, without which there would be neither civilization nor progress.”
To conclude, it would seem that in climate lawsuits, the appeal to human dignity and other supra-constitutional principles might become an unspoken invitation to loosen the interpretation of legal standards where science is uncertain but the foundations of human life are at stake.
 The use of attribution science was crucial in providing evidence to prove standing already in one of the first and most important climate cases, Massachussets v. EPA (2005). See, in this regard Michael Burger, Jessica Wentz and Radley Horton, ‘The Law and Science of Climate Change Attribution’  Columbia Journal of Environmental Law Vol. 45 No. 1 (2020): Volume 45.1.
 ‘First Climate Case Reaches Brazil’s Supreme Court’ (Grantham Research Institute on climate change and the environment) <https://www.lse.ac.uk/granthaminstitute/news/first-climate-case-reaches-brazils-supreme-court/>
 Moreover, the Neubauer claim is logically dependent on the Carvalho one, as it claims that the German Government, by only complying with the EU target, is acting in violation of its obligations under the Paris Agreement.
In order to access the Court, the claimant has to prove to have been affected in one of her protected rights or interests. This legal requirement is called standing. For a definition, see: https://opil.ouplaw.com/view/10.1093/law:epil/9780199231690/law-9780199231690-e79