Coal industry and business giants are pushing the Environmental Protection Agency to backpedal on its proposed regulation of existing power plant emissions, despite warnings from environmental experts that the limits already do not go far enough to stave off climate crisis.

Partnership for a Better Energy Future, which represents 140 leading coal and oil industry and other business groups including the Chamber of Commerce and National Mining Association, sent a scalding letter Monday night to EPA chief Gina McCarthy, slamming the agency’s proposed new regulations on carbon emissions from current power plants as “disruptive” and “arbitrary.”

The EPA proposal, introduced in June as part of President Obama’s climate plan, aims to cut the carbon dioxide emissions of existing power plants to 30 percent of 2005 levels by the year 2030. The agency opened a 120-day public comment period on the proposal.

The industry letter charges that the proposal would “negatively impact the economy,” exceeds the EPA’s authority, and is not technologically achievable. The letter urges the EPA to “go back to the drawing board on this rule.”

Yet, Bill Snape, senior counsel for the Center for Biological Diversity, told Common Dreams that the proposal “is in fact incredibly modest” and that “phasing out coal” is humanity’s only option.