In the latest reminder of how much the judicial branch matters to climate policy and environmental progress, a federal judge appointed by President Trump has intervened to block the Biden Administration from considering the impacts of climate change when it makes decisions about everything from emissions regulations to fossil fuel drilling approvals.

US District Judge James Cain of the Western District of Louisiana's injunction takes aim at what's often referred to as the "social cost of carbon." In other words, he ruled that the government had no basis for measuring the climate and health impacts of each ton of (carbon or methane) emissions, including sea level rise and extreme weather from droughts and wildfires to hurricanes and floods.

Why It Matters

Measuring climate impacts is not only critical; it's common sense -- akin to cancer risks and regulatory decisions about cigarette labeling. Air pollution is one of the leading causes of early death and reduced life expectancy worldwide. And climate change is directly linked to events such as fires, heatwaves, hurricanes, and increased incidences of vector-driven diseases, such as Lyme disease and West Nile.

The combined twelve years of conservative leadership in the US -- eight years of the Bush Administration and particularly four years of the Trump Administration -- reshaped America's courts. From rulings on gas lease auctions in the Gulf of Mexico to this injunction against measuring the social cost of carbon, conservative jurists have aimed at one of the Biden Administration's most potent tools in the climate fight, executive authority. More importantly, big climate cases are winding their way through the federal judiciary, and some will reach the Supreme Court next year.

If climate advocates in Congress lose the majority, the Administration will have to rely on regulatory authority more than ever.

A Ray Of Hope

It should be noted that historically, the Supreme Court has upheld US Administrations' prerogatives to regulate greenhouse gas emissions.

It is also worth remembering that where and by whom climate cases are heard matters immensely. After the Biden Administration was forced to continue with an offshore drilling lease auction by one Louisiana judge in 2021, it was invalidated by a 2022 ruling in a DC court, giving the Administration greater flexibility. Similarly, this decision in Louisiana was (and is) controversial, as a similar lawsuit by the fossil fuel industry had been thrown out in Missouri.