Trends: socio-economic, climate change
Nearly all of the growth of the London population is and will be accommodated by further densification of development around high transport accessibility nodes. This intensifies vulnerability by concentrating the number of people and assets within a relatively small area. Three major climate threats can be identified:
London is vulnerable to ‘tidal’ flooding when tidal surges combine with high tides and onshore winds, ‘fluvial’ flooding from the freshwater rivers in London and ‘surface water’ flooding, when heavy rainfall overcomes the drainage system. London is protected from flooding by a series of flood defences and the drainage system, but the standard of protection varies throughout London. A significant proportion of London’s critical infrastructure lies in flood prone areas and in addition some of the poorest Londoners also live in areas of tidal flood risk.
Eighty percent of London’s water comes from the River Thames and River Lea. The former is the largest river basin in the southeast of England and offers the most dependable supply of water during droughts. However, abstraction is high and the whole of the southeast England is classified as ‘severely water stressed’; the current high water abstraction to meet demand is causing damage to the environment.
Summers in London are rarely hot enough to cause a significant health impact. However, the August 2003 heat wave caused 600 deaths in the city, which is disproportionally high compared to other UK regions. It is likely that the heat island effect was a key factor in this excess mortality, as it prevented the city from cooling off overnight.
Climate change is expected to result in warmer, wetter winters, and dryer, hotter summers. This will increase the frequency and intensity of the abovementioned existing risks, which unless London adapts, will increasingly affect the prosperity of London, the quality of life of Londoners and ultimately London’s reputation as a leading ‘world city’.