reword to sound different: This article considers the substantive and procedural challenges facing a novel private climate litigation strategy: derivative action proceedings for breaches of the directors' duty of care and diligence. Using the ClientEarth claim against Shell as its guiding example, this article compares the likelihood that directors' duties could be used as a tool for climate action in Australia and the UK. It argues that procedural issues surrounding questions of good faith and whether such proceedings are in the corporation's best interests overshadow the potentially widening scope of directors' duties vis--vis identifying and managing climate-related risks. Despite ClientEarth's unsuccessful 'test case', it has provided a roadmap and foundation for future climate litigation, which is valuable within the broader system of environmental law and policy.