14 May 2014: A new Heatwave Plan for England has been published today by the Public Health England. With respect to London, the Plan mentions:
- Extreme temperatures on the London Underground network could lead to a range of health and safety challenges.London Underground network operations monitor Met Office weather forecasts, and if temperatures are forecast not to fall below 24°C for three days running they will get ready to implement plans to deploy hot weather notices and bottled water supply, as well as measures to prevent track buckling.
- On a critical issue for London which is air pollution, the Plan states that – smogs typically accompany heatwaves as these often occur during periods of limited dispersion and /or easterly continental air masses arriving in the UK. As a result pollutants are less well spread or added to a higher background concentration which can lead to high concentrations of nitrogen dioxide and particulate matter. Heatwave conditions often lead to increased ozone levels following interactions of other pollutants with sunlight.
The Heatwave Plan also mentions a number factors which are likely to put increasing pressure on the supply of electricity – something which is likely to become more important as climate change impacts grow:
- At a time when energy companies traditionally maintain power stations for the winter by standing units down over the summer, rising temperatures increase the demand for supply due to the use of air-conditioning units and reduce the power-carrying capacity of the system, as it is harder to cool conductors – this will restrict the ‘maintenance window’ available and could ultimately require greater redundancy on the system to permit maintenance.
- Rising temperatures cause cooling problems for power stations as they are unable to cool components. This effect has been experienced in France, but not yet to a serious extent in the UK.
- High air temperatures are more of a problem and nuclear reactors can trip out at above 40°C, although this has never yet been reached at any site (38°C being the record).
- Rising temperatures lower power station efficiency. This effect is of lower concern than the two effects above.