This week's Radio Ecoshock broadcast is about past greenhouse worlds, quick climate shifts, and mass extinctions caused by changes to the atmosphere. Dr. Andrew Glikson studies comet/asteroid impacts, volcanoes, and past climates. He's been doing it for 40 years. While studying the oldest record of life on Earth, in the Australian outback, Glikson found a relationship between comet or asteroid impacts and the generation of living things. We do not yet know whether life forms (such as bacteria) actually arrived from outer space - or whether the impact generated energy and unique chemical conditions that caused certain natural reactions to duplicate themselves. All that is a side issue to this speech, which is an education on the dominating role of the atmosphere in determining the state of life on Earth. Whether caused by impacts or volcanoes, or even gradual tilts in the Earth axis, a changing atmosphere can make life luxurious - or kill off up to 90% of all species. The science explained by Andrew Glikson in this speech find a parallel in the book "Under A Green Sky" by Peter Ward, a scientist in Washington State. We are talking, for example, about the Permian mass extinction, about 200 million years ago. The ocean lost it's oxygen, and life surived in only a few pockets of the ocean. Most land species were exterminated. Of the five past great extinctions (we are apparently living in the 6th extinction now) - FOUR WERE CAUSED BY CLIMATE CHANGE. Not hits from outer space. For the survival of our species, we need to know what happened - and few people alive know more than Andrew Glikson, as he summarizes not only his own research, but the general science now developing in the field. This speech from Australia National University explains our current shift toward a hot-state planet - much faster than ever before. It has been slightly modified for radio, (to fit in an hour) with the permission of Dr. Glikson. Learn about your planet (or die?) The Radio Ecoshock Show 080704 1 hour CD Quality 56 MB or Lo-Fi 14 MB Alex Radio Ecoshock Less