EdelmanAfter a two-year review, Edelman promises to ban coal companies and climate change deniers from its client roster. Bravo!

The PR firm has taken heated criticism and suffered high-profile resignations due to its representation of companies that contribute to global warming.

Those defections include the embarrassing departures earlier this year of the New York, Chicago and San Francisco leaders of its "business & social purpose group," a practice designed to "help clients bring together profit and purpose."

Critics found it disingenuous for Edelman, an early-adopter of internal carbon accounting systems and strong sustainability advocate, to work for climate change deniers such as the American Petroleum Institute and American Legislative Exchange Council, a stalking horse for the Koch Brothers' anti-green agenda. It simply just didn't smell right. API and ALEC left Edelman before its just-installed ban.

The PR firm now sees the light and says such clients are simply bad for business and a blow to its legitimacy.

Richard Edelman personally decided that the firm founded by his father, Dan, should get out of the coal business, the No. 1 contributor to climate change.

COO Matthew Harrington wrote in a memo that climate deniers and coal producers threaten Edelman's reputation and business prospects.

The ban on coal and climate deniers extends to phony front groups organized to spread misinformation and half-truths of "greenwashing" in order to spread doubt on the existence of warming.

Richard Edelman has long been the most influential leader of the PR business. In exiting the coal business and banning greenwashers, he demonstrated that leadership once again.

The decision of the world's biggest PR firm to acknowledge the threat from global warming will have an impact from beyond the PR community.

Hats off to Edelman and his firm!