Fahn's background has prepared him well for the many challenges the Sierra Club faces. For nearly two decades he has represented a wide array of individual, small businesses, environmental and community groups in his solo law practice. Since 1998 he has also served as the Executive Director of As You Sow, a San Francisco based non-profit organization dedicated to environmental advocacy and consumer activism. One of the most prominent enforcers of California's Proposition 65, As You Sow works to hold corporations accountable for complying with consumer and environmental laws, including Proposition 65, and the Clean Air and Clean Water Acts.

water policy, nuclear power, mountain lion hunting, off-shore oil drilling, toxics enforcement and parkland acquisition, to name a few.

Since he was first elected to the national Board of Directors in May 1999, Fahn has focused on protecting endangered species, developing the Sierra Club's Environmental Justice program and launching a national Corporate Accountability campaign. He was also instrumental in the development of a family of environmentally friendly Sierra Club Mutual Funds. Fahn was re-elected to the Board of Directors in 2002. That same spring he was elected by his fellow board members to serve as the national vice president for conservation. He was elected to the position of president by the Board in May, 2003.