Climate Litigation is new and rising—it requires continued efficiency to sustain accountability and promote resiliency

First, national judges are by and large successfully adapting their traditional role of administration of justice to the new challenges posed by climate change litigation. Presented with a number of novel and urgent legal questions, they have increasingly held their own governments accountable under national constitutional principles, implementing legislation, or common-law doctrines. Since 2013, as one court noted, courts have increasingly "recognized the role of the third branch of government in protecting the earth's resources that it holds in trust."' 1 6 1 Thus, though climate litigation will continue facing different substantive and procedural hurdles in different jurisdictions—from standing to the political question doctrine—courts have demonstrated that, generally, they are rising to the task and using the tools at their disposal for administration of justice in this emerging area.

This trend can be greatly enabled by making the emerging cross-jurisdictional jurisprudence in this area more readily accessible to judges around the world. Likewise, climate literacy training aimed at building judicial awareness of climate science, climate impacts, and climate resilience imperatives can help equip judges to perform their traditional role of administering justice in the context of this global phenomenon.

Thus far, constitutionally protected environmental rights have represented the most straightforward vehicle for climate litigants in some jurisdictions (e.g., Norway), although litigation based on broader rights (e.g., to enforce fundamental constitutional rights to life and property) has also provided a viable strategy in other jurisdictions (e.g., Pakistan). In still other jurisdictions, courts have relied on the language of environmental statutes and common-law doctrines to mandate agency rulemaking or more effective implementation of climate policies (e.g., Foster). A number of lawsuits may not even present climate change as the core issue, but may have an indirect impact on climate mitigation or adaptation efforts by 161. Foster et al. v. Washington Dep't of Ecology, No. 14-2-25295-1 SEA, Order Denying Motion for Order of Contempt and Granting Sua Sponte Leave to File Amended Pleading (Wash. Super. Ct. Dec. 19, 2016) (citingJuliana and Urgenda). regulating conventional pollutants in a manner that may have climate co-benefits (e.g., Gbemre).

The experience to date suggests that courts are more willing to exercise an active role in guiding regulatory development where the statutory framework has proven ineffective (e.g., Leghari), as well as where States' actions to avert climate harm are seen as out of step with national policy or international commitments (e.g., Urgenda). Resort to international legal principles as a means of defining the scope of the State's legal obligation appears to occur most frequently when the content of national law is ambiguous (e.g., Urgenda; Leghari), and in legal systems that permit a direct uptake of international law.

Second, while courts to date have been unwilling to impose civil liability on private entities, especially in the United States where the majority of these suits has been brought, emerging science appears likely to feed additional litigation insofar as it helps to address some of the causation and apportionment hurdles that have made these cases challenging. Also, additional and collateral avenues for private-sector accountability may emerge. For example, following the announcement that several state attorneys general and the Securities and Exchange Commission in the United States are investigating energy companies for allegedly misleading investors and the public about climate change, a securities fraud class action was filed against an energy company relating to climate change and non-disclosure of climate-related risks. 162

Finally, while few national judges to date have been called upon to adjudicate transnational climate claims, several recent cases, supported by emerging climate research, appear likely to lead to an increase in cases of this kind.

Overall, the number of climate lawsuits is unquestionably on the rise, positioning the courts for an increasingly vital role in ensuring climate-related accountability, enabling resiliency, and contributing to a sustainable future.