Royal Society statement on climate change

The world's nations are gathering in Copenhagen in an attempt to reach agreement over how to prevent dangerous interference with the climate, the stated aim of the United Nations Framework Convention on Climate Change (UNFCCC).

There is no such thing as 'safe' climate change. Even the global temperature increase to date (about 0.75˚C) is contributing to effects that are impossible to adapt to in some regions, notably small low-lying islands and coastal areas. As the temperature rises further, so will the risk of more widespread and dangerous climate impacts; from sea level rise, from increasing frequency and intensity of climate extremes such as heat waves, floods and droughts, especially in vulnerable areas.

A maximum global temperature increase of 2˚C since pre-industrial times has been adopted by many nations as a goal to prevent dangerous climate change. If global greenhouse gas (GHG) emissions are reduced at 3 - 4% per year after 2020,it has been estimated that there is a fifty-fifty chance of limiting global temperature increase to roughly 2°C;but only if GHG emissions begin to decline within the next decade. By 2050, emissions would need to be down to near 50% of their 1990 levels, with continuing reductions in the second half of this century.

It is not only the rate of GHG emissions that matters, but also their accumulation over time, particularly for the long-lived gases such as carbon dioxide (CO2). Once our actions have raised concentrations of CO2 in the atmosphere, levels will remain elevated for more than a thousand years. The crucial role played by the cumulative emissions of CO2 means that the later global emissions peak, the more rapid the eventual decline would have to be, which would likely cause economic and social disruption across the globe.

via blogs.mirror.co.uk

Posted via web from Global Warming News