The most general form of adaptation by infrastructures vulnerable to impacts of climate change is investment in increased resilience, for instance in new sources of water supply for urban areas. Most fields of infrastructure management, including water, sanitation, transportation and energy management, incorporate vulnerabilities to changing trends of supply and demand, and risks of disturbances in their normal planning.
In a situation where climate change, observed or projected, indicates a need for different patterns or priorities in infrastructure planning and investment, common strategies are likely to include increases in reserve margins and other types of backup capacity, attention to system designs that allow adaptation and modification without major redesign and that can handle more extreme conditions for operation. In many cases an issue is tradeoffs between capital costs and operating expenditures.
With regard to infrastructure where adaptation requires long lead times, such as water supply, there is evidence that adaptation to climate change is already taking place. An example would be the planning of British water companies mentioned in Section 18.104.22.168.1 above, undertaken at the behest of the UK Environment Agency (Environment Agency, 2004). Another would be the decision taken in 2004 to install a desalination plant to supplement the dwindling flows available for water supply for the city of Perth, Australia (Chapter 11, Section 11.6).
The infrastructure whose adaptation is especially important for the reduction of key vulnerabilities is that installed for flood protection. For example, London (UK) is protected from major flooding by a combination of tidal defences, including the Thames Barrier, and river defences upstream of the Barrier. The current standard for the tidal defences is about a 2000 to 1 chance of flooding in any year or 0.05% risk of flooding, and this is anticipated to decline to its original design standard of a 1000 to 1 chance, or 0.1% risk of flooding, as sea level rises, by 2030. The defences are being reviewed, in the light of expected climate changes. Preliminary estimates of the cost of providing a 0.1% standard through to the year 2100 show that a major investment in London’s flood defence infrastructure of the order of UK£4 billion will be required within the next 40 years (London Climate Change Partnership, 2004). The capacity of storm drainage systems will also need to be increased to prevent local flooding by increasingly intense storms (UK Water Industry Research, 2004).