As pointed out in an article posted on Grist, Stevens has had his fingerprints on several major environmental issues. Stevens wrote the majority opinion in Massachusetts v. EPA in 2007. In that case, Stevens ruled that the EPA can regulate heat-trapping pollutants since, in his opinion, the pollutants were a danger to public health.
Stevens is also known for consistently defending government agencies’ ability to regulate based on vague legislation.
Assuming she is confirmed, Kagan’s actions are hard to predict. A New York Times article written when Kagan was facing confirmation for appointment as solicitor general suggests the former Harvard Law dean is open-minded about environmental issues such as cap-and-trade.
Whatever Kagan’s philosophies are regarding the environment, they will be known shortly. There is currently one suit filed by Texas over the federal government’s right to regulate carbon dioxide. With a cap-and-trade bill being discussed as Stevens steps down from the bench, it is likely that more challenges may soon come before the high court.