A warmer world, billions of people exposed to hunger and disease, shrinking biodiversity, retreating glaciers, expanding deserts. These are just some of the changes the world can expect from climate change. Few now dispute the science behind global warming. A 2007 report by the United Nations' Intergovernmental Panel on Climate Change (IPCC) has become the bible of climate change.
The latest synthesis confirms that scientists' views have become firmer on global warming since the last report in 2001. It refers to “new and stronger evidence” of the impact of climate change on ecosystems, such as mountains and the Polar regions, and concludes that the earth is more vulnerable than the previous report assumed.
New knowledge
But new knowledge is emerging constantly and last year's IPCC conclusions are already being overtaken. The North Pole could have ice-free summers as early as 2013, according to a recent academic study published too late to be included in the IPCC report. Global sea levels have been rising one and a half times faster than previous IPCC forecasts. These studies are cited in a review of new science compiled by British scientist Tina Tan for WWF, a conservation group, that was published in October.
The IPCC has been criticised for not taking sufficient account of so-called feedback effects, by which the results of climate change intensify warming and trip the climate into even higher temperature rises. Once Arctic ice has melted to water, it absorbs the sun's energy rather than bouncing it back into the atmosphere, which leads to more warming and accelerates further melting. Scientists are also investigating the melting of the permafrost, but there is no agreement on its role in climate change.
