Following a 2007 Supreme Court ruling, the U.S. Environmental Protection Agency (EPA) has proposed the first Clean Air Act standard for carbon pollution from new power plants.

The rulemaking proposed March 27 only concerns new generating units that will be built in the future and does not apply to existing units already operating or units that will start construction over the next 12 months.

Currently, there is no uniform national limit on the amount of carbon pollution new power plants can emit. As a direct result of the Supreme Court’s 2007 ruling, the EPA in 2009 determined that greenhouse gas pollution threatens Americans’ health and welfare by leading to long-lasting climate changes that can have a range of negative effects on human health and the environment.

EPA says the proposed standard is flexible and would help minimize carbon pollution through the deployment of the same types of modern technologies and steps that power companies are already taking to build the next generation of power plants.

The agency says the proposed standards can be met by a range of power facilities burning different fossil fuels, including natural gas technologies that are already widespread, as well as coal with technologies to reduce carbon emissions.

The power plants that are currently projected to be built going forward would already comply with the standard, the EPA says; therefore the agency does not project additional cost for industry to comply with this standard.

EPA says it has engaged in an open public process to gather information to aid in developing a carbon pollution standard for new power plants. The agency is seeking additional comment and information, including public hearings, as it completes the rulemaking process. EPA’s comment period will be open for 60 days following publication in the Federal Register. More information can be found at epa.gov/carbonpollutionstandard.