The Supreme Court on Friday declined to block Biden administration limits on planet-warming methane from oil and gas production and toxic pollution from coal plants. 

The high court denied requests from red states and the industry to temporarily halt the Environmental Protection Agency (EPA) regulations. It did not explain its reasons for doing so, and no dissents were noted. 

The decision leaves two key rules in effect while cases against them play out in lower courts. 

The methane rule requires oil and gas wells to control leaks of methane, a greenhouse gas that is more than 28 times as powerful as carbon dioxide and is the main component of natural gas.

The pollution rule requires coal plants to emit less lead and arsenic, among other toxic substances.  

For some coal plants with historically looser limits on emissions of mercury, a neurotoxin, the rule also requires them to release less of this pollutant. 

While these two rules remain in effect for now, it is still possible that they could ultimately be overturned through ongoing legal proceedings. 

The Supreme Court still has not said whether it would grant a similar request to block a separate rule regulating carbon emissions from power plants.  

The high court has in recent years undercut the federal government’s ability to protect the environment from harm, restricting how it can regulate planet-warming emissions and narrowing the scope of its water protections. 

Zach Schonfeld contributed.