So far human greenhouse gas emissions have raised the temperature of the planet by one degree Celsius.http://english.aljazeera.net/indepth/features/2011/06/2011622132049568952.html
The Al Jazeera article goes on to list impacts felt RIGHT NOW - including high food price - floods -wildfires - loss of biodiversity - and acidifying oceans. Meanwhile, the UK Guardian has created a huge FAQ on climate change in the hopes of educating people. Find it at http://www.guardian.co.uk/environment/series/the-ultimate-climate-change-faq
Media in Canada don't seem to pay attention to climate change - and Canada's politicians do nothing. The Conservatives do nothing - and are reviled for it - but the Liberals signed the Kyoto Accord and then did dick-all as well. Why? Well , Stephan Dion was soundly punished at the polls for presenting a green platform that took climate change seriously. Therefore, presumably our politicains do nothing because we don't really want them to take action. We aren't exactly rioting in the streets,are we? ( Well, we're not rioting because we're worried about the impacts of climate change.)
Denial ain't just a river in Egypt! And arguing with people in denial ends up reinforcing their defenses - what's a poor activist to do? Work through ready made communities - church groups - chambers of commerce - etc and tailor your message to the group.
And work on yourself - meditate - and work on seeing everyone in the world as connected to everyone and everything - and as worthy of your love. Then, when you carry out your activism, you will do so with loving kindness and compassion. I think it's the only chance we've got.....