On 31 July 2020, the Irish Supreme Court issued a decision in the case of Friends of the Irish Environment v Ireland that has been praised as a great victory for the struggle against climate change. In this judgment, the Court quashed the national climate change mitigation plan adopted by the Irish government for falling well short of the standards required by the enabling legislation. This article analyses this decision from a comparative perspective and provides a critical appraisal of its impacts on the advancement of climate litigation. It focuses in particular on the contribution of the case to the understanding of two common legal hurdles in climate litigation: standing and separation of powers.