PORTLAND — Curt Spalding, the U.S. Environmental Protection Agency’s Regional Administrator, will be in Portland tomorrow to lead a roundtable discussion about proposed federal standards that would regulate greenhouse gas emissions at new coal-fired power plants.

Carbon dioxide emissions from coal plants are believed to be the leading cause of greenhouse gases, and the rule change will make it harder for new plants – existing plants would be grandfathered – to stay within the required limits.

The forum, which will be held at the Cumberland County Civic Center’s lobby meeting room, will provide Mainers with a look at what the new standards would mean for Maine.

The discussion will also offer state forestry and tourism officials, physicians, energy experts, scientists, and local elected officials the opportunity to offer their perspective on the new standards.

Thursday’s forum is scheduled to last about 90 minutes, and will begin at 10:30 a.m. The public will have an opportunity to ask questions.