Crossing a threshold

David Korten, in his wonderful book The Great Turning indicates that around the 1980 we crossed an evolutionary threshold, by placing a burden on the life support systems of the Earth beyond the sustainable limits. In the last 50 years the population grew more than double, from 2.6 billion to 6.4 billion in 2005. The number of motor vehicles is ten times what it was in 1950. Fossil fuel use is five time what it was, and global use of water has tripled. It is only 27% of the world population who enjoyes material affluence to consume goods and services. We are consuming at a faster rate than the resources of the Earth regenerate, that means that at this rate of consumption we would actually need 1.2 Earth equivalent planets. But we only have one. So we are depleting the natural capital of the planet: minerals, fossil fuels, forests, fisheries, soil, water. We are extracting these resources at the expense of our children and the next generations.

The WWF (World Wildlife Fund) publishes a Living Planet Index, that tracks the health of the planet through its freshwater, ocean, forests and coastal ecosystems. The index declined 37% between 1970 and 2000. They say it's unlikely to reach zero - a dead planet - "because the planet will surely rid itself of the offending species long before this occurs".