Why did Bloomberg Tap the Sierra Club for his $50 Million Donation?

Why the Sierra Club?

They were the lucky environmental group to get $50 million pledged from Bloomberg Philanthropies Thursday. Turns out that Mayor  Bloomberg, who was the nation's second largest donor in 2010, has been chummy with the senior leadership of the Sierra Club since 2007. Carl Pope, former executive director of the Sierra Cub, was present at the launch of the city's Greener Greater Buildings Plan in 2009, one of the mayor's signature environmental achievements.

"He is interested in playing a leading and ongoing role as an environmental philanthropist just as he has and continues to play a leading role as an environmental mayor and civic leader," said Rohit Aggarwala, who heads up environmental donations at Bloomberg Philanthropies.

Aggarwala, who was the "sustainability guru" behind PlaNYC 2030, was quickly recruited by the mayor last summer just months after he left city government. He's one of many in the Mayor's close circle who have made the transition from public service to working in Bloomberg's private empire (examples include former Deputy Mayor Dan Doctoroff, now running Bloomberg L.P., and current Deputy Mayor Patricia E. Harris who is simultaneously acting as chief executive and chairwoman of the multibillion-dollar Bloomberg Family Foundation). The mayor clearly trusts him, as Aggarwala has gained approval to give away $68 million of Bloomberg's cash over the next four years.

Earlier this spring, Bloomberg Philanthropies pledged $18 million over four years to the C40 Cities Climate Leadership Group, an association of major cities around the world committed to reducing carbon emissions and slowing climate change, where Bloomberg himself is currently chair.

The Sierra Club's Beyond Coal initiative, which aims to convert aging coal power plants to clean energy, fits into Bloomberg's public health and climate change agenda, as well as his strategy of focusing on local initiatives, Aggarwala said.

"This fits into the much broader and in fact much larger tradition of his philanthropic giving to public health issues, whether it's tobacco, or global road safety, or an earlier grant he gave years ago related to Malaria, public health around the world, around the country and locally have all been major concerns of his and key areas where he's donated money."

Bloomberg has announced on numerous occasions he plans to give away all of his fortune, saying his definition of good financial planning is making sure the check to the undertaker bounces when it's finally time to go. If he gives away this year as much as he did last year- $279.2 million - donations to environmental causes would make up about a quarter of his entire philanthropy in 2011.