The big announcement is coming later this morning, but NPR’s Elizabeth Shogren had the scoop already:

The Sierra Club is getting a big boost in its effort to shut down coal-fired power plants. New York Mayor Michael Bloomberg is supporting the organization’s efforts with a donation of $50 million. The plants produce nearly half the nation’s electricity. But they also pump out lots of pollution that contributes to climate change, makes people sick and causes premature deaths.

Once efforts to embargo the story were out the window, The Washington Post went with their story, reporting:

Sierra Club executive director Michael Brune described the gift from Bloomberg Philanthropies, which will be spread out over four years, as “a game-changer, from our perspective.” The group will devote the money to its “Beyond Coal” campaign, which has helped block the construction of 153 new coal-fired power plants across the country since 2002.

Bloomberg and Sierra Club officials were to appear together later this morning outside a coal-fired plant in Alexandria, Va., for the announcement.

The Sierra Club said:

In the U.S. coal is the leading cause of greenhouse gas emissions, and coal’s pollution contributes to four out of the five leading causes of mortality – heart disease, cancer, stroke, and respiratory illness. Coal emits almost half of all U.S. mercury pollution, which causes developmental problems in babies and young children, as well as being a major contributor to asthma attacks. Coal pollution causes $100 billion in health costs annually.

Bloomberg said:

If we are going to get serious about reducing our carbon footprint in the United States, we have to get serious about coal. Ending coal power production is the right thing to do, because while it may seem to be an inexpensive energy source the impact on our environment and the impact on public health is significant. Coal is a self-inflicted public health risk, polluting the air we breathe, adding mercury to our water, and the leading cause of climate disruption.