Earth ‘on fast track’ to warming
18/2/2006 BBCBy Paul Rincon BBC News science reporter, St Louis The findings came from probing sediments on the ocean floor Greenhouse gases are being released 30 times faster than the rate of emissions that triggered a period of extreme global warming in the Earth’s past. That is the conclusion of scientists who presented results at a coference in St Louis, in the US. Emissions that caused a global warming episode 55 million years ago were released over 10,000 years. Burning fossil fuels is likely to release the same amount over the next three centuries, the scientists claim. Professor James Zachos of the University of California at Santa Cruz studied the period of global warming known as the Palaeocene-Eocene ’ Thermal Maximum (PETM). Temperatures shot up by 5C (9F) during this episode, driven by a massive release of carbon dioxide and methane into the atmosphere. Crossed threshold. By probing sediments on the ocean floor, Professor Zachos was able to determine that about 4.5 trillion tonnes of carbon entered the atmosphere over a period of 10,000 years. If present trends continue, this is the same amount that will be emitted by burning fossil fuels during the next 300 years, according to the UC Santa Cruz geologist.