The climate crisis narrative continues to be spun by the Guardian and its willing collaborators. Today the headline is “Millions of homes in London, Essex and Kent at risk of sinking as climate crisis worsens – Analysis pinpoints areas most vulnerable to hotter, drier weather causing ground to shrink and drag foundations down”. The article is based on a press release issued by the Association of British Insurers (ABI).

The Guardian manages to turn a short ABI press release into a fairly long article. Happily for them the ABI is fully signed up to the climate crisis narrative, claiming:

Subsidence-related insurance claims totalled £153 million in the first half of 2025, as households across the UK felt the impact of an exceptionally warm and sunny spring, according to figures from the ABI….

…The ABI’s figures follow unusually high spring temperatures, with the Met Office confirming the UK experienced its warmest spring on record this year – with above-average temperatures across all four nations.

There’s even an obliging quote from Louise Clark, Manager of General Insurance Policy at the ABI:

Climate change is significantly increasing the risk of subsidence in the UK, particularly in areas with clay-rich soils that sink and swell in response to changing moisture levels caused by hot temperatures.…

Undoubtedly, high temperatures and reduced rainfall will contribute to potential issues with subsidence as they result in soil drying out. But I couldn’t help feeling that the climate change narrative is unduly simplistic, not least since whatever else spring 2026 was (whether or not it was warmer than average) it wasn’t hot in the way a summer might be (other than for a few days in late May in parts only of the UK). The press release mentions a couple of other directly relevant factors – the bulding of houses on clay soils, and the effect of trees and shrubs in drawing moisture from the soil.

Not surprisingly, it turns out that the majority of subsidence claims are in London and the south east of England. Climate worriers will triumphantly claim that this is the part of the country that is “suffering” hot, dry summers because of the “climate crisis”, and it’s certainly true that this is the part of the UK that experiences dry, warm weather. But the situation is massively compounded by the fact that this is an incredibly densely populated part of the country where millions of homes are built on clay soils.

The Geobear website informs us that:

A vast area of England, particularly the London and South East regions, is built on shrinkable clay soil. This type of soil is highly susceptible to changes in moisture – it swells when wet and shrinks dramatically during dry spells. This shrinking and swelling is the primary cause of over 75% of subsidence cases.

In fact, insurers have identified 226 postcodes that are most susceptible to subsidence claims, all located in the clay-rich south-east of England.

The Speedcheck website amplifies on that:

Clay soils are widespread across southern and south-eastern England, forming a significant engineering challenge for construction projects. The most well-known of these is the London Clay Formation, a thick, fine-grained sediment that underlies much of Greater London, Essex, Kent, and extends into parts of Surrey, West Sussex and Hampshire. This clay is notorious for its susceptibility to moisture changes, expanding when wet and shrinking when dry, which can cause ground movement and structural issues if not properly managed in foundation design…

…Clay’s shrink-swell behaviour is a common cause of differential settlement and subsidence, especially under shallow foundations that cannot adapt to seasonal volume changes. These challenges are particularly pronounced in densely populated zones of London and the wider Southeast, where infrastructure and buildings are frequently affected by soil movement.

Note that the problem is seasonal – expanding when wet and shrinking when dry – rather than a simple problem of shrinking when dry (which would fit the climate crisis narrative better).

Logically, the solution would seem to be to cease building in such areas. However, as a paper sponsored by the Peel Group in 2019 notes, we have:

a Government response which is somewhat one-dimensional in its approach, explicitly directed at stipulating an unprecedented boost in the supply of new homes in the areas of highest demand and greatest unaffordability, most of which are concentrated in London and the South East. This manifests itself in both the method for planning for housing and in the allocation of funding to support new provision.

Although that observation is seven years old, I suspect not much has changed since then. The current Labour government has ambitious plans for house-building, and as the i newspaper reported:

Under the plans, 24 per cent of the 370,000 homes built each year are set to be built in London, while 19 per cent will be in the South East and 11 per cent in the South West. These regions will be expected to deliver just under 200,000 homes between them.

The London borough of Kensington and Chelsea will have a significant increase in its house requirement, with the estimated local housing need revised from 847 homes a year to more than 5,107, an increase of over 500 per cent.

Builders and architects are aware of the problems of building on clay soil, and the approach to foundations has been refined in recent years. Indeed, it seems that pre-1965 properties seem to be most at risk, so it is to be hoped that mass house-building on inappropriate soil won’t result in more subsidence claims.

However, there is another problem, an ironic one given that the focus on the “climate crisis” and the acknowledgement of the severe impact of the urban heat island effect means that there are many strident voices calling for more of them – trees.

The Guardian article tells us that:

Highly populated parts of London including Camden, Islington and Barnet are most susceptible, as well asKent in the south-east of England.

I enlisted the help of AI, which says:

Camden, Islington, and Barnet all exceed the average tree cover across London. Barnet and Camden are consistently ranked among the leafiest boroughs in the entire capital, well ahead of the city-wide average.

A report for the Islington Society suggests:

The overall canopy cover of the borough of Islington is estimated at 25.0%. In comparison with other studies (Urban Tree Cover, 2018), the canopy cover is above the average (17%) estimated in the 320 towns and cities surveyed in the UK. In comparison to the rest of London, Islington is above the average of 21% canopy cover.

It is suggested that Islington could reasonably aspire to a canopy cover of 30% by 2050 subject to the production of a fully costed and resourced action plan, and in alignment with the target of London to achieve 30% canopy cover.

Why? Because (ironically) as the report tells us:

Trees are arguably the single most important component of Green Infrastructure (the mosaic of parks, street trees and all other ‘green assets’ found in urban areas), yet are often overlooked and undervalued. In particular, trees are important because they enhance and improve the urban environment by providing a wide range of benefits (or ecosystem services) at relatively little cost. For example, there is a growing body of research which demonstrates that trees improve our health and well being. Trees also provide a ‘sense of place’, moderate extremes of high temperature in urban areas, improve air quality and act as a carbon sink.

What a dilemma. We need trees, and lots of them. But you plant them too close to houses (and fail to prune them) at your peril.

Postscript

It’s always worth considering the sensational headline claims in detail, in order to put them into context. The ABI press release advises that:

Over the first six months of the year, insurers supported almost 9,000 households in recovering from subsidence damage, with the average payout per claim standing at £17,264.

Two points stand out from that. The first is that the payments were made by insurers in order to deal with existing subsidence claims over the first six months of the year. These are not claims that solely manifested themselves in those six months. Even if they had done so, the winter was wet, not dry. Headlining with a £150M+ figure, and suggesting that it is due to a dry spring (which is in turn alleged to be due to a climate crisis) is a piece of legerdemain, and should be called out. The ABI obligingly said the subsidence claims occurred “as households across the UK felt the impact of an exceptionally warm and sunny spring”. Patently, claims paid out in the first six months of 2026 were not the result of weather in the second quarter of 2026.

Secondly, tragic though the subsidence damage is for those affected by it, it actually affected a relatively small number of properties. According to the ONS there were 28.6 million households in the UK in 2024. If the Government is anywhere close to hitting its house-building targets, it seems reasonable to assume that there are 29 million in 2026. Thus, the subsidence claims relate to approximately 0.03% of UK housing stock. Tragic for the people affected, but far from a crisis.