Article - Issue 28, September 2006
Dr Scott Steedman FREng FICE
Dr Scott Steedman FREng
We need a strategy for adaptation that draws upon the science of climate change but which is driven by engineers – a decision maker’s tool for adapting to an uncertain climatic future.
Stone Age man walked across a great river valley to colonise the land we now call Britain. As the ice sheet melted sea levels rose, flooding the channel and slowly forming our present coastline. Today’s schoolchildren are shown river terraces and taught that sea levels rise and fall. Climate change is as old as the earth.
For around 40 years the temperature of the earth’s surface has once again been on a rising trend. Solar activity and the amount of water vapour in the atmosphere are two of the most important natural controls in this very complex system. In terms of anthropogenic effects, we know that human activity can influence global climate – our success in reducing sulphur emissions in the 1960s and 1970s (remember acid rain?) had the perhaps unhelpful consequence of removing the cooling influence of atmospheric aerosol particles. Today, the growing world population, the growing economies of developing countries and growing global demand for energy are three likely sources of CO2 emissions with a strong potential ‘forcing’ effect on climate change.
The effects of climate change may be broadly grouped into three categories. The first is gradual change, such as rising temperatures or longer rainy seasons. The second is an increasing frequency of ‘extreme’ events, such as hurricanes, downpours and droughts. The third is defined by the Intergovernmental Panel on Climate Change (IPCC) as ‘large scale singular events’ such as the collapse of the Gulf Stream, the disintegration of the West Antarctic Ice Sheet (which would stimulate further large-scale sea level rise) or the desertification of large parts of Africa.
Given the difficulty of reaching scientific consensus over the range of the likely rise in global temperature, the chances of reaching agreement over these consequential effects – the increased probability of extreme events, or the onset of one-off ‘surprises’ – seems very remote. We can all support the principle that cutting CO2 emissions is highly desirable. Agreeing a policy of global mitigation when the benefits may only emerge after several decades seems a worthy strategy, but may prove difficult to implement.
Fortunately there is another path, largely neglected to date, that is beginning to emerge. The excellent House of Lords report entitled The Economics of Climate Change (July 2005), debated in the House on 14 July 2006, and the current Stern Review for the Treasury on the same subject, look closely at the real cost of each climate change scenario that we face. They suggest that much more weight should be given to policies of adaptation, as opposed to the current emphasis on mitigation. In the context of the UK, DEFRA is already developing a national adaptation policy framework.
Adaptation is a pragmatic approach local to each environment. In many ways this approach is entirely consistent with the continual process of development and infrastructure renewal that is an essential part of wealth creation and economic growth. The implication by some that adaptation is somehow a ‘bolt-on’ additional cost that developing countries cannot afford (such as flood defences, water transfer schemes, power and communications) misses the point that if the economies of developing countries are indeed to converge with the developed world (a key assumption in the IPCC scenarios), then by definition the value of those economies will sustain the necessary investment.
Adaptation is a path led by engineering rather than science, which is perhaps one reason why it has had a low profile in the climate change debate. Two other key groups are essential in developing any adaptation policy. The insurance industry is important in dealing with extreme events – risk management is an entirely appropriate solution to many environments – and agriculture is essential because of the crucial link between infrastructure and farming in all functioning economies.
The House of Lords report calls on the government ‘to ensure that greater efforts are made to understand the relative costs and benefits of adaptation compared to those of mitigation’. We need this and more. We need a strategy for adaptation that draws upon the science of climate change but which is driven by engineers – a decision maker’s tool for adapting to an uncertain climatic future. It would be entirely appropriate for the Academy to take the lead.
Dr Scott Steedman FREng