§ Lord Juddasked Her Majesty's Government:
What recent studies they have made of the West Antarctic ice sheet and of the consequences of its collapse; and what were their conclusions on necessary international action to meet any such threat. [HL2975]
§ The Parliamentary Under-Secretary of State, Department for Environment, Food and Rural Affairs (Lord Whitty)In research commissioned by Defra, an interdisciplinary panel of experts were asked to summarise the state of scientific knowledge and uncertainty and estimate the risk of a sea level rise of over four metres due to the collapse of the West Antarctic ice sheet (WAIS). The study revealed a wide range of opinions on the stability of the WAIS and concluded that it would most likely not collapse in the next few centuries, although they estimate a 50 per cent probability of WAIS causing sea level rise of at least 10mm per year within 200 years. There is still much uncertainty about the behaviour of the WAIS: whether it is still adjusting to changes after the last ice age and how it will respond to climate warming and contribute to sea level rise. Both the British Antarctic Survey (BAS) and the Hadley Centre continue to assess the impacts of climate change on ice sheets both in the Arctic and the Antarctic through observational and modelling studies. The collapse of the WAIS over a period of centuries would raise sea levels by some six metres with a major impact on low-lying countries and coastlines.
International action to reduce greenhouse gas emissions through the Kyoto Protocol is the first step in a long process to reduce emissions enough to stabilise greenhouse gases at a level which avoids dangerous anthropogenic climate change. There is 26WA however no international consensus as to what that level should be. The EU has proposed that carbon dioxide concentrations below 550 parts per million should guide emission reduction efforts, but what level would be required that to avoid loss of the WAIS is a matter for further research.