hard to say..... i think we are probably nearing a tipping point with reagrds to a man made geological event.. i don't however think that will be it for the planet, or even for us..
Most large cities are near the sea, so with rising sea's and more extreme weather patterns i think there could be a huge loss of life over the next 100-200 years, simply from land-loss and therefore less aggricultural output, as well as more hurricanes, tornado's, droughts and flash floods, not to mention the growth of deserts and desalination of the ocean causeing very different temperatures in Europe, and maybe elsewhere as well (ie spain turning into a new sahara, the Uk dropping 10 or so degree's in temperature)... But we are an adaptable species and will suvive in some form.

and even if we don't the planet will... the majority of the planetwide ecology 65 million years ago died and the planets not a wasteland today... or look at the Ice age 10,000 years ago. Im sure that looked catastrophic at the time... As thet said in Jurasic park, life always finds a way.

Yeah, the mistake some people seem to make is equating climate change to the destruction of the planet. There will be loss of life, but the planet will be fine. It's us we need to worry about. Us and all the other various species under threat. We may vanish but the Earth will keep on keeping on. And someday an ecosystem will develop in which even the plastics are consumed and will become part of the natural world.

I'm optimistic that, once the first major event happens, as the rising waters begin to claim a major city, people will stop being complacent. In the West especially, complacency sets in very quickly, and it takes these big events to really get people motivated to change.

not the strongest.... but the most adaptable

and i think Guildy is not saying that it doesn't matter for us, he and i and forkboy are all saying it doesn't matter for the planet... I think we can all agree that things need to change, but they probably wont untill we allready have had a massive loss of life/ habitable zones..

I'd say we are getting close to it. How far off? No idea. There are changes been made to environmental practices etc but it seems so small and inconsequential...Gildermershina is right about the complacency part...I don't think nearly enough people have got a grasp on what could happen, it's almost as if 'lalalalalala...nothing's wrong, its all good!' It all seems fantastical to a lot of people in terms of rising seas, increasingly frequent and violent weather events, loss of habitable and arable land and so on. I suppose for it to be at least slowed down (don't know if you can even stop it) humanity really need to go all out and change the very ways we go about our lives but until something catastrophic happens, it seems unlikely.