Supreme Court Justice Anthony Kennedy, a 1988 Reagan appointee, will leave behind a mixed environmental law legacy. Best known to the public as a crucial swing vote on issues regarding same-sex marriage and abortion rights, Kennedy’s influence on environmental law was no less impactful, as he sided both for and against ecological and public health interests in numerous significant decisions and was almost always in the majority. But on the whole, Kennedy’s retirement will negatively impact the Supreme Court’s environmental jurisprudence; this is because a Trump-nominated successor—whether Brett Kavanaugh or otherwise—will create a five-seat conservative majority hostile to issues of environmental protection and climate action.