This short “elevator pitch” on global warming has one very good metaphor. That’s the part where he says:
These changes are occurring very fast. We are on a very fast train heading for the wall.
This is true when looking at the pace of change in geological time scales. The speed of changes is off the charts.
Climate change has occurred without burning of fossil fuel in the past. But it has never happened so fast.
In the history of humanity (around five million years) the last 2000 years amount to less than one percent. The last 200 years (where most of the fossil fuel was burned) amount to less than 0.1 percent.
If humanity wants another five million years of survival, we better slow down that train. And we better do so before it hits the wall.
Fortunately, while the pace of change is extremely fast in geological time scales, it is slow when compared to human life spans. It is not like a 500 km asteroid scheduled for impact next year, or global nuclear mutual destruction happening in a couple of minutes.
Humanity still has a couple of decades left to put the brakes on that train.