In Australia a wowser is someone who believes other people having fun is bad. An enviro-wowser is someone who frowns on other people's activities if they are believed to use too many resources. It's a modern form of wowserism for the middle class.
The enviro-wowser was annoyed because we had lights on at the party. The enviro-wowser was shocked to see her date drive up in a V8.