Al Gore: If we don't take action there could be as many as 1 billion climate refugees

"If we don't take action there could be as many as 1 billion climate refugees crossing international borders in the next several decades. Well a few million has contributed to this wave of populist authoritarianism and dictatorships..., what would a billion do. We can't do this, we could lose our capacity for self governance. Already we're seeing people driven from the places they've always called home and we're seeing an expansion of areas in the world that are physiologically unlivable now because of the combination of heat and humidity. They're relatively small areas now, but if we don't act they will expand to include most of India, large parts of Northern South America, the Philippines, Indonesia, Pakistan...The survival of our civilization is at stake and it sounds dire because it is dire..."