The London Climate Resilience Review is warning that London and UK are “underprepared” for climate change impacts like flooding and extreme heat and that London faces “lethal risk”.

The warning comes in the newly published interim report by the Review which is calling for immediate action now to prevent major flooding damage to London.

Following the flash floods in 2021 and the 40-degree heatwave in 2022, the Mayor of London commissioned the independent review to take stock and make recommendations to guide London’s preparations for more extreme weather.

In London the extreme flooding of July 2021 damaged homes and properties, costing local authorities tens of millions, with aggregate insured losses estimated to be over £100 million, displacing residents and disrupted critical services to vulnerable Londoners.

Key findings include:

• Despite some progress in preparing for the impact of extreme heat and surface water flooding, London is underprepared for the frequency and severity of climate change currently experienced. A “step change” in adaptation planning and investment is needed to allow the capital to withstand the disastrous effects of climate change, such as more intense and frequent heatwaves, more intense rainfall, flash flooding and sea level rise.
• Climate change presents a lethal risk to Londoners with some communities more vulnerable than others, including low-income households, the elderly, minority communities, children and youth and vulnerable health groups.
• The lack of a clear strategic vision from the national government is hindering progress at a regional and local level.
• Adapting London will benefit the UK as a whole, given the capital’s economic importance and the presence of critical national infrastructure, including transport hubs and key hospitals.

“In the absence of national leadership, regional government has a more significant role to play”

Emma Howard Boyd CBE, Chair of the Review, said:

“London has many good plans and programmes to prepare for climate hazards but we need to recognise that Londoners now face lethal risks, and a step change is needed. Last year was the hottest on record and this is causing chaos and disruption all over the world. London is not immune, as shown by the flash floods in 2021 and a 40-degree heatwave in 2022.

“I am really pleased that the Mayor has agreed to support an exercise to prepare for even more severe heatwaves than we saw in 2022. This is a positive step that will help London organisations plan to protect more Londoners in future shocks.

“In the absence of national leadership, regional government has a more significant role to play. We need pace not perfection. It’s time for the UK, led by its cities and regions, to take action and prioritise adaptation. That is an opportunity to make the UK economy more climate resilient, to protect the most vulnerable, to preserve all that we love about London and to show leadership to other cities nationally and globally.”

The Review will present a final report to the Mayor later in the year. The interim report’s key recommendations include:

• London should conduct a multi-agency exercise to test the city’s preparedness for a period of extreme heat.
• Whitehall should give councils more funding and powers to adapt their communities for climate change, instead of making local authorities compete for limited central,money.
• Improvements are needed to housing standards to ensure homes are resilient against climate change, including heat and flooding.
• Action is needed now to prevent major flooding damage to London, including developing an action plan for where flood defences need be raised before 2050, installing sustainable drainage systems and creating a Strategic Surface Water Authority to tackle flooding caused by heavy rain.
• The Mayor should lead collaborative work with local authorities and the private sector to set out a clear strategic vision for climate adaption in London by 2030.

The Mayor of London, Sadiq Khan said:

“I would like to thank Emma Howard Boyd, the Review team and everyone who has contributed to this Interim Report and its recommendations.

“Work led by City Hall and London Boroughs has long been underway to prepare the capital for the increasing frequency and intensity of climate risks, like flooding, heatwaves and drought. However, the harsh truth is that the increasing frequency and intensity of these events and a lack of action by the Government has left our city - and nation - vulnerable to extreme weather.

“I welcome these recommendations and have proposed in my latest Budget an additional £3 million to accelerate climate adaptation work in London. We will be looking at how we can take forward the recommendations identified so far and urging others, especially Government, to do the same.

“I can also confirm today that the London Resilience Partnership will carry out an exercise later this year to test London’s preparedness for a severe heat episode and that my green finance programme will begin work to consider how adaptation finance, including naturebased solutions, can be accelerated in early 2024.”

London’s main climate risks are:

• Rising sea levels and the need to strengthen the Thames’ defences.
• Surface water flooding, as seen in the past few weeks alone.
• Heat, with London having already hit 40°C for the first time in 2022.
• Drought – if no action is taken by 2050, the UK’s national water supply will face a shortfall of nearly 4 billion litres a day. Lack of water supply will cost London’s economy an estimated £500 million a day.
• Wildfires, such as those seen in Wennington in 2022.

Baroness Brown of Cambridge, Prof Dame Julia King DBE FREng FRS, Chair of the Adaptation Committee of the CCC (Climate Change Committee), said:

“In recent years we've seen a 40-degree heatwave, water shortages, wildfires, floods and storms in London. This year El Niño will almost certainly and tragically underline the need to make climate resilience a much greater national priority. I urge Ministers to read this report and understand the need to make short and medium term commitments, we cannot afford to continue to kick into the long grass issues like sea level rise in the Thames.”

Sir John Armitt, Chair of the National Infrastructure Commission, commented:

“The truth is that London is not ready to cope with the likely weather changes ahead. This interim report lays out what needs to happen to fix that, including an honest public conversation about the costs of securing reliable transport and utility services in the face of a changing climate. That requires infrastructure operators to calculate those costs, informed by expert advice from the Met Office. The Commission commends the ongoing work of the Review team and its coherent plan of action.”

The Review gathered evidence from individuals, communities and organisations including the NHS, Transport for London, London Fire Brigade, the Metropolitan Police, Borough Councils, the GLA, UK Government, NGOs, the financial services sector, sports and cultural institutions as well as representatives of vulnerable groups.

In 2022, there were 3,271 heat related deaths in England and 387 in London. The 2022 heatwaves would not have happened without climate change but many of those deaths would have been preventable. The heatwaves caused widespread failure of green infrastructure including street trees, in Epping Forest alone a total of 76 fires were reported between 26 June and 16 August 2022. The extreme heat stretched water supplies, melted road surfaces and caused disruptions to rail infrastructure. Social care, education and health care face major disruptions across London. The aggregate costs are not known.

Cllr Kieron Williams, London Councils’ Executive Member for Climate Change, Transport and Environment, said:

“Londoners are already experiencing the severe impacts of climate change, from heatwaves to flash flooding. Alongside the work we’re doing to cut carbon emissions, we urgently need to make our city more resilient to the more extreme weather we are already seeing, so we can protect our diverse communities and way of life. This timely review into London’s preparedness is a clear call to action. London boroughs look forward to working with our partners across the capital to act on these recommendations, so together we can make London safer and greener.”

The Review’s findings will be split into two parts. This is the Review’s interim report, which sets out strategic and urgent recommendations. The Review’s full report will be published later in 2024 and will include the Review’s full findings and complete set of recommendations. This report sets out 20 recommendations which call for strategic, delivery, capacity building or investment actions. The Review has indicated high level timeframes for recommendations. Recommendations are directed to stakeholders across London, including the Mayor of London, UK government, local authorities and the community and voluntary sector. More recommendations will be set out in the final report.

Patrick Begg, Outdoors and Natural Resources Director at the National Trust, said:

“As we head towards a General Election, all politicians should give climate adaptation the immediate, unswerving attention it deserves, so the UK can be better prepared for the weather extremes we are increasingly experiencing. We support the review’s timely call for a cross-Government, Cabinet Office Minister for resilience and adaptation, and urge all parties to commit to increase support for nature-based solutions to climate change and to put climate adaptation at the heart of their manifestos.”

Click here to download the London Climate Resilience Review’s full interim report