Green Drinks is a social get together for anyone interested in sustainability issues and has been a great success in the past, with over 20 people on the mailing list and regular attendance of about 8 people.
It is a free-standing group, for which a replacement organiser is currently needed. This will only take an hour or two of your time a month, plus the meetings themselves. Maybe you would consider sharing the role with a couple of others? This is quite possible as there are already a couple of people who may be prepared co-run the group.
If you are interested in attending or taking on the role of organiser please email firstname.lastname@example.org