Hi. This meetup is a legacy from when I chaired Sierra Club NYC Group, 2008 - 2010. Because of how a small number of long-term volunteers have managed it, the SC NYC group is virtually defunct. A brief look at its website conveys the superficial impression that it holds events, has active committees, and engages volunteers. Not so. http://nyc.sierraclub.org/
Ken Baer and Jim Lane have been running the NYC group and steering the NY State Chapter for nearly two decades as their personal fiefdom. What appears to be a functioning group is a charade, made possible by well-meaning but naive volunteers who enable Baer and Lane. To maintain their status as officers-for-life, and keep enough of their cronies around to guarantee control of the Group's Executive Committee, Baer and Lane committed fraud and libel in the 2010 group election, abundantly documented here. http://www.sierraclubnyc.blogspot.com/
Some Sierra Club members in NYC, affiliated with the State Chapter, are very active on the hydrofracking issue. If you want to do activist projects, that's a good place to be. Also try www.UnitedforAction.org.