In July 2020, in a country in which courts consistently defer to the executive, the Irish Supreme Court invalidated the government’s climate strategy. The National Mitigation Plan had outlined some vague measures, deferred most action, and acknowledged that short-term emissions would increase. NGO Friends of the Irish Environment argued it was ultra vires and that it violated the rights to life, bodily integrity, and a healthy environment. In an important victory for climate activists and litigants, the Supreme Court upheld the ultra vires claim and quashed the Plan, requiring the government to produce another. But this success was overshadowed by the court’s retrogressive and gratuitous findings which narrowed the existing doctrine on standing, essentially rejected the relevance of human rights provisions, and denied the existence of a derived right to a healthy environment. The judgment raises questions as to whether climate litigants should pursue a narrower range of grounds and how litigants might approach standing and the right to a healthy environment in future. It highlights the urgency of making strategic use of regional and international mechanisms in addition to domestic courts and the need for litigants to be upfront about the necessity of innovative legal reasoning in climate cases.