tehanu writes "Scientists working with Antarctic ice have found that the level of greenhouse gases is at the highest level in over half a million years. Carbon dioxide is 27% higher now than any other time over the last 650 000 years. Methane, an even stronger greenhouse gas is 130% higher. The period of time studied covers eight full glacial cycles including a time when the earth's position relative to the sun is the same as it is today. Other scientists have found that the annual rate at which the sea has risen since the industrial revolution is twice that of over the last 5000 years. It is predicted that by 2100 the sea level will be 40cm higher. These results provide strong evidence that human activity since the industrial revolution, rather than just natural processes, has strongly altered the world's climate. As one of the scientists involved in the research put it: 'The levels of primary greenhouse gases such as methane, carbon dioxide and nitrous oxide are up dramatically since the Industrial Revolution, at a speed and magnitude that the Earth has not seen in hundreds of thousands of years.'"