One of the United States’ first environmental laws, the Clean Air Act, was passed in 1963. The act allowed the Environmental Protection Agency (EPA) to regulate power plants by setting a “standard of performance” for the emissions of certain pollutants. Individual states implemented that requirement by restricting emissions for existing power plants. 

The Clean Air Act has been amended numerous times. One such revision was in the form of the 2015 Clean Power Plan, which established guidelines for states to limit carbon dioxide emissions from power plants and turn to renewable energy sources instead. The Trump administration pushed back, passing the Affordable Clean Energy Rule to repeal the Clean Power Plan. 

The U.S. Court of Appeals vacated the Affordable Clean Energy Rule, finding the law “arbitrary and capricious.” Among many others, the North American Coal Corporation, challenged the court, questioning the EPA’s authority. 

In front of the Supreme Court, the question was simple: does the Environmental Protection Agency have the authority to regulate greenhouse gas emissions if their policy considers cost and energy requirements? 

In a 6-3 decision, the Supreme Court ruled that the EPA does not. 

This case was the first time where the Supreme Court’s majority explicitly invoked the “major questions doctrine.” When an agency seeks to exercise authority on an issue of major significance, it must be supported by clear congressional approval. A majority in the Supreme Court found that there was no such  “clear Congressional approval” of the EPA’s authority to regulate carbon dioxide emissions in existing plants, and thus was invalid. 

Justice Neil Gorsuch wrote a concurring opinion, in which he argued the importance of the major questions doctrine, stating that it protects against “unintentional, oblique, or otherwise, unlikely instructions” on areas of “self-government, equality, fair notice, and the separation of powers.”

Yet with the least legislatively productive Congress in the last five decades, this ruling sets a dangerous precedent. Invoking the major questions doctrine effectively means that Congress’ past legislation does not carry on into the future if any circumstances change: in our case, the greater threat of climate change. It erodes stability because previous laws would not even have to be explicitly repealed to be nullified. 

As the Brookings Institute points out, this  case indicates that the legislature “must continue to assert itself to orient our federal government’s responses to the leading challenges of our time.” 

Even Section 111(d) of the Clean Air Act, what the majority argues is “too broad” and vague, was clearly intended to give the EPA flexibility. It states “​the degree of emission limitation achievable through the application of the best system of emission reduction which the [EPA] Administrator determines has been adequately demonstrated.”

In the current context, the ruling halts the EPA from setting emission caps. 

Justice Elana Kagan’s dissenting opinion points out how President Biden had announced his plans to develop a new policy on emissions, “yet this court determined to pronounce on the legality of the old rule anyway. This court could not wait—even to see what the new rule says—to constrain EPA’s efforts to address climate change.”

With the Earth warming 20 times faster than its natural rate, the threat is indisputably imminent. But instead, the Court went against their fundamental purpose—to decide Constitutional issues—and took a stance on legislative policy instead.