Mr Tea, fortunately or unfortunately, most people's opinions are not that important. What are the opinions of the people who actually govern the country (not necessarily politicians, of course!)--that's the relevant question.
What I'm saying is, if issues relating to climate change and environment at large were sufficiently important to a sufficiently large number of people, the Greens would be a major force in parliament, or even form the governement, rather than being a small fringe party that gets a few local councillors here and there.
I think a lot of people are vaguely aware that there is Trouble brewing but either feel that it is suffiently far off in the future or happening far away, or that there's no point trying to do anything serious about it because it's now inevitable, and that even if everyone in Britain became a self-sufficient crofter overnight, what good is that really going to do when China's building car factories faster than we can build cars?