Environment - Call of Life
Theres a mass extinction occurring on our planet today. We may well lose half of the worlds biological diversity, but do we know enough about whats going on to be scared by? Natural structures that have been solid for millions of years are now in chaos. Plant and animal numbers are quickly dropping and species are becoming extinct faster than ever before. Scientists have begun to call this a mass extinction event. Extinction happens, thats a fact. Something like 95% or more of all the life forms that have lived on Earth went extinct naturally. The difference today is that the rate of extinction vastly exceeds the rate of evolution of new species. So over time weve typically had the situation where more species were evolving into being than were going extinct. Today we have a dramatic cutback in whats out there. The natural rate of extinction is about one in a million. Within a year the natural, geological background rate of extinction should involve one species in a million going extinct. Today we estimate that there could be several dozen species effectively going extinct every day. Extinction rate now is at least 100 hundred times, soon will be 1,000 times, conceivably 10,000 times greater than it has been in the prehistoric past. Its like looking out at a beach and seeing that its disappearing. You dont need to have identified and put a name to every grain of sand out there, much less counted all those grains of sand to see very clearly that theyre disappearing. There has never been anything like this in human history. The only precedence we have are really catastrophic declines in the geological past. Weve documented five mass extinctions in the geological record over the last 500 million years and these are quite dramatic events. 65 million years ago an asteroid is believed to have hit the planet somewhere near the Gulf of Mexico and the result of that impact was the destruction of systems that supported life all over the world. It was something like 85% loss of life.