Climate change litigation has been growing in importance over the past three decades as a way of either advancing or delaying effective action on climate change. This report reviews key developments around the world in climate litigation over the period May 2019 to May 2020, in the latest in annual series. The report highlights evolving themes and strategies, including an updated assessment of known case numbers and metrics for categorising cases. It explores the continued and growing focus in climate cases on human rights and the different strategies used in recent litigation against major fossil fuel companies. It also offers insights and suggestions for how litigants and policymakers could measure the impacts of climate litigation.