2022 saw UK temperatures soar to above 40°C for the first time, while 2023 was the world’s hottest year on record. Westminster’s Environmental Audit Committee has raised concerns over the UK’s lack of preparedness in its report on ‘Heat resilience and sustainable cooling’.

• Read the report summary
• Read the full report
• Read all publications related to this inquiry, including oral and written evidence

The “silent killer” of heatwaves could claim up to 10,000 lives annually in the UK without concerted action, with the most vulnerable at greatest risk. Physical and mental health can be severely impacted: the Committee heard that suicide risk is twice as high in the UK when the temperature was 32°C rather than 22°C.

Work-related injuries also increase, and interrupted sleep patterns due to high temperatures can cost the UK economy £60bn a year, or 1.5% to 2% of GDP.

The social and economic case for accelerating heat adaptation measures in the UK is clear-cut, and EAC recommends measures around prioritising passive cooling – that do not involve expending energy – and clear Government messaging on the risks of heat events, underpinned by a national strategy on heat resilience.

Nature based solutions offer important passive cooling measures and additional co-benefits. Parks, trees, water bodies and green infrastructure – such as green roofs – can have significant cooling effects and also help biodiversity and air quality.

The Government must adopt a range of these measures, particularly in areas where the ‘urban heat island’ effect typically raises temperatures: for example, London can be up to 8°C warmer than surrounding rural areas.

Over 4.6 million English homes experience summertime overheating, and with 80% of homes that will exist in 2050 having already been built, retrofitting for net zero and thermal comfort will be needed on a vast scale.

Existing initiatives on insulation and energy efficiency should be developed into a national retrofit programme which should be delivered by local authorities, supported by long term funding, focusing on insulation and ventilation, as well as passive measures, above active cooling mechanisms.

Fans may also have a role, and the Government should consider amending Building Regulations to encourage the use of ceiling fans. The Government must urgently bring forward proposals to encourage access to low-cost finance for householders to retrofit passive cooling measures.

Some of the passive measures EAC heard about included installing external shutters, which could reduce incidences of heat mortality by around 40%, and coating the roofs of buildings with reflective white paint.

Passive cooling measures would reduce the need for energy intensive air conditioning units, which in 2022 and 2023 led to a surge in demand for electricity causing coal fired power stations to fire up once more. A repeat of this surge risks a vicious cycle of increased greenhouse gas emissions that in turn make the world even hotter. Action to increase the energy efficiency of air conditioners is therefore also required.

Any national retrofit programme must be well-funded but also address concerns of a “net zero tradespeople crisis” amid concerns that by 2030, there will be a shortfall of 250,000 people in suitable roles.

Information on coping with extreme heat does not always appear to be reaching those in need. Repeating calls the predecessor Committee made in its 2018 Heatwaves report, EAC urges the Government to launch a public information campaign on the developing threat of heatwaves and their significant impact on human health and activities.

The Met Office should trial naming heatwaves to boost public recognition of the threat to health and wellbeing in the same way as named storms. Humidity levels should also be incorporated into weather forecasts and heat-health alerts.

At COP28, the UK signed the Global Cooling Pledge, which saw nations commit to reduce cooling related emissions by 68% from 2023 by 2050. EAC hopes its report assists the Government’s production of a national cooling action plan as the pledge calls for, and in response to its report, the Government should set out its timetable for this plan.

Environmental Audit Committee Chair, Rt Hon Philip Dunne MP, said: “The world is heating up, and in the coming year we may exceed an increase of over 1.5°C above pre-industrial levels: breaking a key ambition of the Paris Agreement. The record temperatures we are seeing in UK summers, triggered by climate change, pose significant risks to health and wellbeing, and swift action must now be taken to adapt to the UK’s changing climate.

“Projections suggest that without action, there could be 10,000 UK heat-related deaths annually. High temperatures are costing the UK economy £60 billion a year: so measures to address the risks from overheating are simply a no-brainer.

“There are a number of relatively simple ways to mitigate overheating risk, such as installing shutters, increasing the size of green spaces and using reflective paint on roofs. Yet none of these measures are being rolled out at scale. There is now a real opportunity to focus on these measures in tandem with improving the energy efficiency of the country’s homes in a new national retrofit programme.

“Tackling overheating at scale will not be a quick or easy undertaking. Clear collaboration between Government departments and local authorities is necessary, supported by a clear messaging campaign and a pipeline of funding and skilled retrofitters to undertake the work needed.

“Existing Government policy fails to grasp the urgency of the task at hand. A Minister with oversight on heat resilience must be appointed to oversee this important work.”

Dr Radhika Khosla, Associate Professor at the Smith School of Enterprise and Environment, University of Oxford, who acted as Specialist Adviser for the EAC’s inquiry, said: “We were delighted to partner with the EAC for this timely and important inquiry.

“Sustainable cooling has rightly been pushed up the global agenda in recent years as temperatures rise around the world. But now that we recognise the problems from extreme heat, it is imperative we commit to the solutions.

“Our hope is that this report helps the UK take action to meet its Global Cooling Pledge commitments and, most importantly, helps to save lives and protect people’s wellbeing while reducing emissions from cooling.”