I'm thinking the key to youngsters become involved with the environment is to bring it into their awareness at a young age. This applies to both education and parents. At a very young age in primary school, my class was taken into a local wood and taught at a very basic level about the trees (eg, 'draw this tree's leaf - this is a sycamore tree. Trees produce oxygen...and so on). We also encountered herbs and animals, finding much delight in the squirrels as I remember! I still visit this wood today on occasion. Sadly, I think my school was in a minority in this regard.
I applaud your efforts and think that people like you, my primary school teachers and probably every member of this board are important in a culture shift that is much needed. Environmental issues need to be raised and taught by schools, parents, the media and role-models. If we can show younger people what is out there in non urbanised/industrialised Britain, they will at least have a chance to love it, and naturally want to protect it. A long, slow process this is, but look how things have changed in the years since the industrial revolution. Keep pluggin' away!
Edit: as an afterthought, perhaps the more cynical people would find more enthusiasm in doing something proactive rather than reactive. Eg; instead of (or preferably as well as!) recycling, they could be getting involved in campaigns that put pressure on businesses/politicians for reductions in unnecessary packaging.