This is a good article, in that it points out we can't wait for some kind of ultimate catastrophe to decide do something. Once we reach that decision point, things are going to continue getting catastrophically worse until we can somehow get fossil fuel burning down to zero.

One good metaphor I think is the standard classficiation formula for hurricanes. With each 20-30 mph increase in wind speed, the associated damage increases exponentially. Each new level of wind speed makes the previous level insignificant by comparison. With each new level you're just that much farther from what the world was constructed to expect.

That is basically where we're going. As CO2 level increases we move from peripheral effects at marginal areas to drowning major cities (as just one example). The damage increases exponentially. And it’s not just the symptoms but the rate of change as well that increases with CO2 content.

So the single most important message to get across is that we can't wait for catastrophes to act. Otherwise what we thought were catastrophes will look like nothing compared to the inevitable reality.