@zipperlip; we've become so interdependent that planes can be crashed into heavily populated areas with devastating impact, essential service fibre cables are prone to acts of terror, a single freighter getting stuck in the Suez Canal can disrupt global trade, the total pollution load attributable to human activity already greatly exceeds the Earth's 'carrying capacity' and hurricanes can sink a fully loaded oil tanker in Manila Bay.
Many moons ago people were concerned that we were on the eve of destruction ... so what's changed?
