Climate change is happening now and it's happening faster and much worse than predicted. It's threatening to the world we know and everything in it. It's already killing people. This is beyond doubt or argument.
We have just years to change course. If we manage it, we could save the world, at least the one we recognise. Realistically, the prognosis at the moment is that we won't manage to steer the ship around in time.
So why have we, as people with everything to lose, not acted sooner?