Climate change: an update

'Climate Change is Real'

This was the clear message at the Woking LA21 Climate Change event. Dr. Chris Gordon, Head of the Government Meteorological Research Programme of the Hadley Centre, Met Office described the evidence from the Intergovernmental Panel on Climate Change Report 2001 which is the consensus of 1,800 scientists worldwide. He pointed out that the few scientists with alternative views were given a disproportionate emphasis by the press, which also regarded fluctuations of weather as contradicting global warming. In fact natural fluctuations do occur but the overall trends are what matter.

Since the late 1800s as industrialisation took place, 'greenhouse' gases such as carbon dioxide and methane have dramatically increased: they act like a blanket so not all of the heat, irradiated from the earth's surface, is able to escape, so that the earth has warmed by 0.6⁰C. This may not seem very much but evidence from tree rings, ice cores etc show that 'the increase in temperature of the 20th century is likely to have been the largest of any century during the past 1,000 years'. Marked changes are already occurring such as glaciers retreating worldwide.

Complex mathematical models have been developed and tested against temperature records of the past 140 years. Considering natural factors like sun spot and volcanic activity, there would have been a decrease at the end of the last century. However, by including the effects of manmade pollution, there is a close match as shown in the graph. The IPCC report states `There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities'.

The climate models have been used to test different scenarios for the future which depend on how man controls gas emissions. Worldwide there could be very significant effects on agriculture and water supply as rainfall patterns change, diversity of species will decline as they are unable to adapt to new conditions, more extremes of weather like storms and droughts will have devastating effects, new diseases affecting man, animals and plants are likely to spread even into Europe, sea levels will rise causing islands to disappear and coastal flooding in areas like East Anglia.

Very recent results of the UK Climate Impacts Programme (UKCIP) for this century predict temperature rises in SE England of 3⁰C in winter and up to 5⁰C in summer. Rainfall in SE England is likely to increase in winter by 20% with therefore greater risk of flooding but decrease in summer by 40% resulting in more frequent droughts. The projected rate of warming is much larger than the observed changes during the 20^th Century and is very likely to be without precedence during at least the last 10,000 years.

These predictions are indeed daunting but as Dr. Gordon emphasised, the extent of change will depend on our actions. Non-polluting technologies are available but industry needs incentives to invest. The leader of the council Cllr Jim Armitage as chairman of the meeting drew the evening to a close on a very positive note. We can act locally and aim for the Royal Commission target of an 80% reduction in emissions in the next 100 years, which is necessary to stabilise global climate. Step by step we can make a difference. LA21 and the Green Pages are spreading the message. We all need to act, and act now!