Repeated summer heatwaves are likely to have cost the UK economy more than £4bn in lost output so far this year, according to analysis by green thinktank Verdant. The findings highlight the growing economic toll of climate change, with the group's director, James Meadway, calling for urgent government action to protect workers and businesses from extreme heat, warning that costs will worsen in future years.

Verdant's estimate has risen from £2.36bn after June's heatwave to £4.4bn once July's high temperatures are included, with the thinktank warning annual costs could exceed £25bn by 2030 if heatwaves keep intensifying at the current rate. It is calling for a maximum working temperature, compensation for workers who lose hours to heat, and investment in cooler urban green spaces, with London and the south-east likely worst affected. The estimates, based on Allianz research showing productivity drops 3% per degree above 30C, broadly match separate LSE Grantham Research Institute findings of over £1bn lost during June alone, when a survey found 87% of people reported health impacts from the heat. The analysis comes as England faces an amber extreme heat warning, with almost three-quarters of the country now in drought.