about 1,000 people... reaching its 10th anniversary this year, has led to a 24 percent cut in emissions vs. "The EU(27) even with active legal measures have maintained a fairly level CO2 emission rate but have managed to reduce their CO2 emissions/head by ~22% since 2005. " http://euanmearns.com/the-record-of-recent-man-made-co2-emis...
It feels good, but that's about it. Further, per person they are probably doing more damage than the average person in London or other major city.
Trying to work at a community level here will likely get pushback from some property owners (likely remote) who will block any potential or even perceived increase to their taxes/expenditures even if you can prove ROI within 5 years.
I don't think all those efforts are mutually exclusive you know :)