Courtesy of The Financial Times, a look at how climate preparation must be embedded into government’s growth strategy to avoid ‘catastrophic’ impacts:

Protecting London from extreme weather is a matter of “national security”, according to an independent report, which found that flooding, drought and wildfires were putting the UK capital’s economy and citizens at risk.

Preparation for more frequent and extreme climate risks was “non-negotiable”, the London Climate Resilience Review said on Wednesday, estimating that global warming could hit the city’s GDP by 2-3 per cent per year by the middle of the century.

“The lack of co-ordinated preparation for the cascading consequences of climate change across government departments is a clear national security risk,” said Emma Howard Boyd, former chair of the Environmental Agency, who led the review.

“This has been known about for years, so we urgently need to see action at pace and scale,” she added.

If London appeared “unable to manage heatwaves and floods, the impact on investor confidence in the national economy would be catastrophic”, Boyd said.

She added that climate resilience must be embedded in the Labour government’s growth agenda and that “adaptation is non-negotiable”.

Boyd said that, as well as ensuring that measures for the built environment, such as the river Thames’s defences, were robust, the government needed to understand the “costs of downtime”.

She added that the impact of heat and humidity on labour productivity in London was already valued at £577mn a year.

The review called for local, regional and national governments to work together to enable more investment in climate resilience across the UK.

The final report, commissioned by mayor of London Sadiq Khan, which followed an interim study in January, said that, while assessing the economic impact of climate change was “extremely challenging”, it used two separate modelling studies to underpin its analysis.

Under one scenario, the GDP effect was 2.8 per cent 2041-60, rising to 6.3 per cent by 2081-2100. Under a so-called high-mitigation strategy, this was reduced to about 2 per cent.

The report urged the government to ensure homes and infrastructure were built to withstand extreme weather, to take into account the increased risk of drought, and to develop a plan to deal with wildfires. In Epping Forest alone 76 fires were reported between June 26 and August 16, 2022 amid soaring temperatures.

Khan said climate change was “one of the biggest dangers our capital faces”, adding that he had already seen how “extreme weather can devastate communities, ruin businesses and end lives”.

The report also warned that 43 per cent of London’s properties were likely to be affected by subsidence by 2030, an issue that rose to prominence in 2022 as record-breaking temperatures led to a surge in insurance claims. Heatwaves result in changes to the moisture content of London’s clay soils, unsettling houses in the process.

Khan has set a net zero target for London of 2030 and has focused on rolling out electric buses, shifting taxis away from diesel, planting trees and funding low-emissions neighbourhoods. The city’s greenhouse gas emissions fell by 45 per cent from their peak in 2000-20.

The government said it was: “Committed to protecting communities in London and across the country from the dangers of flooding. That’s why this government will launch a flood-resilience task force to turbocharge the delivery of flood defences, drainage systems and natural flood management schemes.”