46C summer days and ‘supercell’ storms are Britain’s future – and now is our last chance to prepare | Bill McGuire

Neither the Tories nor Labour seem bothered by the climate mayhem that awaits us, but to save lives they must act

It's the August bank holiday in 2050 and the UK is sweltering under the worst heatwave on record. Temperatures across much of England have topped 40C for eight days running: they peaked at 46C, and remain above 30C in cities and large towns at night. The country's poorly insulated homes feel like furnaces, and thousands of people have resorted to camping out at night in the streets and local parks in a desperate attempt to find sleep. Hospital A&Es are overwhelmed and wards are flooded with patients, mostly old and vulnerable people who have succumbed to dehydration and heatstroke. Already, the death toll is estimated at more than 80,000.

No, this isn't the beginning of a dystopian drama, but a snapshot of a mid-century heatwave unless we prepare for the increasingly extreme weather that will be driven by climate breakdown. To say that the government has no credible plan for this, as the UK Climate Change Committee did last week, is - if anything - an understatement. Britain is woefully underprepared for extreme weather, and in a number of key areas we are going backwards. About one in 15 of England's most important flood defences were in a poor or very poor condition in 2022, up from roughly one in 25 just four years previously. The government's Great British insulation scheme is operating at such a slow pace that it would take nearly 200 years to upgrade the country's housing stock, while Labour has rowed back on its ambitious plans to insulate 19m homes within a decade.

Bill McGuire is professor emeritus of geophysical and climate hazards at UCL, and the author of Hothouse Earth: an Inhabitant's Guide