A new report from Central London Forward (CLF), a partnership of the 12 central local authorities, warns that the impacts of climate change could cost London up to £15 billion a year by 2050 without urgent action across all government levels. More frequent and severe heatwaves, floods, and droughts will affect both the health and finances of Londoners.
Urban Heat Island effect exacerbates heat
London has experienced record-breaking temperatures in the last two summers, partly due to the Urban Heat Island (UHI) effect, which can make the city feel up to 10 degrees Celsius hotter than surrounding areas because of heat trapped by dense buildings.
The report emphasizes that the Greater London Authority (GLA) and boroughs can take steps to address both causes and symptoms of climate change. A key recommendation is expanding green infrastructure—parks, gardens, woodlands, rivers, wetlands, urban trees, and planted roofs—to absorb heat, create cooler spaces, and reduce flood impacts.
Green spaces seen as 'soft targets' for cuts
Research indicates that green spaces are often considered 'soft targets' for local authority funding cuts due to a lack of statutory requirements. The authors point to Elephant Park in Southwark, one of the largest new green spaces in central London in 70 years, as an example to follow. Despite high maintenance costs, CLF argues the benefits justify the expense.
Mass retrofitting of social housing should also be a top priority for the GLA, according to the report, though funding is a challenge given over a million homes need attention. Similarly, flood resilience efforts are hindered by outdated infrastructure—City Hall notes that London's drains and sewers, built over 150 years ago, were designed for a smaller city with more green surfaces.
Flood risk from outdated infrastructure
Officials warn: "The combined challenges of London’s growing population, changing land uses and changing climate mean that if we continue to rely on our current drains and sewers, we face an increasing risk of flooding." To combat this, the GLA's Surface Water Strategy promotes permeable paving and Sustainable Drainage Systems (SuDS) across streets, schools, and housing estates. However, CLF says such initiatives "can be difficult to fund and deliver at the scale and pace needed."
The report praises the GLA's Cool Spaces Network, which designates libraries, leisure centres, and shaded parks as public cooling areas, but notes that "the general public is often unaware of their benefit or existence, and it is difficult to establish enough spaces to make a difference."
Call for legislative responsibility
CLF calls for a legislative requirement for local authorities that lack the "strength and political will" to act voluntarily on climate adaptation. This includes embedding climate change as a priority in planning decisions, giving it equal weight to energy efficiency and net zero. Secure, long-term funding for adaptation projects—available on a non-competitive basis—is also needed.
Charlie Rainsford, Assistant Director of Policy and External Affairs at CLF, told the Local Democracy Reporting Service (LDRS): “The effects of climate breakdown are already being felt in Central London, with severe thunderstorms and heatwaves in the space of 24 hours. It is vital that we make Central London more climate resilient so that we can keep people safe, support businesses and maintain London’s place as an attractive place for visitors. However, the responsibility for action currently falls on local authorities, without any sustainable funding or a common framework. We are calling for long-term, consistent and devolved funding for adaptation projects and embedding adaptation in planning policy.”
City Hall's response
City Hall sources highlighted that the Mayor has funded the planting of over 640,000 trees since 2016, including two major woodland creation projects, and the creation or improvement of 900 hectares of green space. A spokesperson for the Mayor of London told the LDRS: “Extreme heat is becoming more common and more intense as a result of the climate crisis and Londoners are already experiencing more frequent heatwaves, including last week’s rare Red Heat Health Alert. That’s why City Hall is working closely with boroughs, health services, TfL, emergency services and community organisations to plan how to mitigate the effects of climate change and is why we’ve established a network of free Cool Spaces, thousands of water refill points and drinking fountains across the capital. Last week, the Mayor launched Heat Ready London, a long-term vision bringing together partners to help our city adapt to rising temperatures, protect vulnerable Londoners, strengthen critical infrastructure and ensure our communities remain resilient in the decades ahead.”
