Heatwave in the UK – ‘altering the design of our cities to beat future heat’

Last week, principal investigator of ACTUAL, Prof. Janet Barlow, appeared on BBC News to discuss the current heatwave in the UK. Over the course of the last week, we’ve been experiencing the warmest temperatures since 2006. It gets particularly hot in our cities as the Urban Heat Island can keep night-time temperatures as much as 6-8 degrees warmer than rural areas due to characteristics such as high heat storage of building materials and dark ‘sun-absorbing‘ surfaces.  Keeping our buildings cool by shading out the sunshine during the day can ease the heat and avoid costly use of air conditioning.

With London and the South East under “Level 3 heat-health watch” alert, the difficulties in managing health and transport infrastructure during prolonged warm periods have been coming to the forefront.  Level 3 includes a definitive call to action for health and social officials to target vulnerable populations such as the elderly, the infirm and pregnant women. Transport in the South East of the UK has been struck by issues such as buckling rails, melting tarmac and delays due to passengers being taken ill on train services. The urban heat island effect increases the possibility of strong overheating warnings in the city as the alerts are triggered by consistent high day temperatures bridged by excessive night-time temperatures above the expected norm.

The Tyndall Centre’s ARCADIA project estimates that by the 2050s, one third of London’s summer may exceed the Met Office current heat wave temperature threshold (Daytime temperature of 32°C and night-time temperature of 18°C).  “Planning for cities resilient to climate change has started now,” says Janet, who will be interviewed on BBC Radio Five Live tonight at 17:25. “Our cities are going to be literally greener! Vegetation both provides shade and cools us by evaporation of water through its leaves. Not only green roofs but green walls will become a more common sight, helping to save energy inside buildings as well as creating a pleasant environment outside.”