@john_sinha I've seen some YouTube clips. Stopping traffic can be an effective tactic but only if its part of a sustained campaign, not just an A to B march on a single day.
Climate change is difficult to deal with for similar reasons to those which Cory Doctorow described. What we have now is not so much climate denial as climate nihilism. It's easier to imagine the end of the world than the end of capitalism.
For most people it's all very abstract. Ethical shopping, smart meters and similar has negligible effect on the problem. The real scary stuff is still perhaps two or three decades away. Things like flooded coastal cities forcing huge migrations and big changes in where food can be grown. Perhaps accompanied by famines on a scale that has never been known before.
Also on a purely practical level environmental protesters are public enemy number one as far as the establishment is concerned. They're prepared to invest considerable resources in infiltrating and disrupting environmental groups. So any campaign should assume that's happening and plan to neutralize the effects.