Start changing behaviour after the IPCC first report came in, in 1990. Waiting until we have not just visible, but dramatic and surprisingly early consequences is leaving taking evasive action in the car until the bodywork has started to crumple. I note that nearly all the surprises seem to be of things being far more or far sooner than predicted...
That leaves dramatic and expensive global scale action. We're not doing it. There's no sign we're thinking about doing it. Let the market resolve is the sole incredibly weak suggestion.
I don't think history is going to view citizens and politicians of the 21st century kindly. I can forgive and understand those contributing to the problem before say 1990, before the awareness was widespread. We've emitted more since 1990 than in the entire time before.
