Greater London

Heatwaves are becoming significantly more intense and frequent in London due to climate change. The Met Office reports that the chance of a 40 °C day in the UK has been rapidly increasing and now is 20 times more likely than in the 1960s [1]. Additionally, the length of warm spells in England has more than tripled, with the highest increase seen in the South East. There, warm spells have increased from around 6 days in length (during 1961-90) to over 18 days per year during 2008-2017 [2]. Prolonged heatwaves, such as those in 2022 when temperatures exceeded 40 °C and nearly 3,000 excess deaths were recorded, put immense strain on public health and infrastructure [3]. The city’s urban heat island effect, where densely built-up areas retain more heat, amplifies these impacts, making London particularly vulnerable, especially in lower income neighborhoods where there is less green areas that mitigate the effects of heat [4].

River flooding is one of the main climate risks in London. The Thames is now expected to rise over 1 meter by the end of the century, meaning that much of the existing flood defences need to be significantly risen [5]. Experts predict that even after 2030, the Thames barrier could be breached and London flooded at any time [6]. In addition, London has many residential basement properties particularly vulnerable to rapid flooding, out of which a significant proportion is social housing [7].