One of President Trump’s signature moves has been rolling back Obama-era regulations on the environment. That’s how the administration ended a key rule on carbon emissions. But the replacement to this rule known as the ACE rule, has raised legal challenges from fossil fuel companies and environmentalists. POLITICO’s Alex Guillen explains. Anthony Adragna is an energy reporter for POLITICO and host of POLITICO Energy.Alex Guillen covers the EPA and environmental issues for POLITICO.Carlos Prieto is a Politico podcast producer.Jenny Ament is the senior producer of POLITICO audio.Irene Noguchi is the executive producer of POLITICO audio. Learn more about your ad choices. Visit megaphone.fm/adchoices