Asset specific litigation
Claims brought using environmental, planning or other regulatory legislation to challenge project-specific authorisations. Prevalent in Australia this category includes challenges to permitting decisions based on failures of impact assessments to appropriately consider climate change.

Public law
Challenges to national or local policy or enforcement practices on the basis of failure to achieve government climate change mitigation commitments. Includes Urgenda case forcing the Netherlands to adopt more stringent national climate policies and UK litigation on the Airports National Policy Statement which blocked the building of Heathrow’s third runway.

Financial & corporate regulation
Alleging insufficient disclosure or breach of duty by directors, pension fund trustees, auditors, etc in relation to under reporting or alleged insufficient consideration of climate risk. Actions have been threatened or brought against financial institutions, corporates, trustees and auditors.

Tort law
Based on negligent misstatement, negligence, nuisance or trespass. These are increasingly being used by local municipalities across the world facing funding shortfalls for climate change resilience measures. It also includes claims such as the RWE case where the German court found for the first time that climate harms can in principle give rise to corporate liability.

Soft law mechanisms
Using OECD Guidelines for multinational enterprises, UN or national human rights forums as the basis for non-judicial claims against corporates whose business operations are alleged in reality not to align with their commitments.

Equality of expectation
Defendants have called out plaintiffs for conduct similar to that alleged against themselves (e.g. failure to disclose information on climate risks).

Disclosure
In response to applications for disclosure of historic GHG research, defendants have challenged “abusive law enforcement tactics” and alleged claimants are stifling their right to participate in dialogue about climate change and policy. Privilege is also sometimes claimed.

Contextualisation
While accepting current science, defendants have highlighted the uncertainties in previous research. Defendants have positioned themselves as moving in concert with research acknowledging that they are now in a position to address climate risks.

Joinder
Applying to join third party defendants on the basis they also used and promoted the use of fossil fuels and should contribute to remediation.

Standing
The requirement in some jurisdictions to show the claimant has suffered a loss capable of sufficient particularisation.

Causation
Difficulties lie in drawing a clear causal link between an individual company’s contribution to global climate change and localised harm suffered by the plaintiff. The science of attribution is developing. Activists have also suggested weakening causation tests (e.g. as for asbestos) for example by adopting a “doubling the risk” principle.

Statutory authority
Where plaintiffs seek to rely on common law tort claims, they face the challenge of the displacement principle. This means where an area of law is codified in statute, common law relating to the same facts may be pre-empted.

Resources
The high costs involved in climate litigation operate as a deterrent for many potential claimants, though activist funding is becoming more common.

Judicial will
Climate change can be perceived as a political issue and some judges have declined to engage.