In March, the World Meteorological Organisation reported that the concentration of carbon dioxide in the Earth’s atmosphere had reached its highest level in the past 800,000 years – and continues to build.

The world has already warmed approximately 1.1-1.3°C above pre-industrial levels (i.e. from 1850 to 1900), and is on track for around 2.5-3°C of warming by 2100. Given that we don’t know what level of future emissions the world will produce, predicting future effects is very difficult.

Subject to the uncertainties above, the Met Office’s latest projections show the UK getting substantially warmer and wetter overall, but with stark seasonal contrasts – wetter winters and significantly drier summers – and more extreme weather events.

Under a “medium emissions” scenario, Britain will warm by a couple of degrees by the end of the century against 1990 temperatures. The changes are regionally variable. London’s annual average temperature is likely to increase by 2-3°C. In summer, very hot days (30-35°C) will occur more often, and extreme days (35-40°C) will become increasingly commonplace. There will be an increase in average winter rainfall, and summers will be drier, but punctuated by intense storms.

What effects will this have?

In its 2025 report, the Climate Change Committee (CCC) lists five key risk areas for the UK. First, the threat from extreme weather to food production and nature (i.e. biodiversity and the ability of land, such as peat bogs, to sequester carbon). Second, the risk of infrastructure disruption: drought putting pressure on water supplies, extreme heat buckling railway lines, and so on. Third, the risk to properties from flooding and overheating. Fourth, the risk of heat-related deaths. Finally, the risk to economic prosperity from climate change. The CCC predicts that economic output could be reduced by up to 7% by 2050 (the Office for Budget Responsibility recently put this figure even higher).

Will food production be affected?

The effects are already being seen. In 2024, flooding followed by very dry weather damaged crops and drove up the price of animal feed. This year’s very low rainfall also affected yields. A study this year found that 86% of farmers had experienced extreme rainfall in the past five years, while drought had affected 78%.

Warming won’t be altogether negative: warmer weather will extend the growing season, and make some crops – chickpeas, oranges, grapes – viable. But dry summers will reduce yields of many staple crops, and of grass-fed livestock. Farmers may need to invest more in irrigation systems. Pollinators may be wiped out. Higher temperatures will allow pests and diseases to thrive. There are also the threats posed by flooding.

What effects will flooding have?

Since 1900, global sea levels have risen by around 16.5cm. Depending on emissions levels, the Met Office anticipates a sea level rise of between 0.3m and 1.15m by 2100, relative to 1990 levels, though around 0.5m is more probable. Rising sea levels cause coastal erosion, destroying homes and habitats, and increasing the likelihood of coastal flooding, which is a particular risk on the east coast. The Environment Agency assesses that 13% of agricultural land is already at risk of river or coastal flooding. The Government thinks more than half of the UK’s prime “Grade 1” agricultural land is at risk. According to the think-tank Climate Central, one-third of Lincolnshire – one of Britain’s most productive agricultural regions – is at risk of being below the annual flood level by 2050.

How will floods affect property?

The Environment Agency estimates that 6.3 million properties across England are now at risk from flooding from rivers, seas and surface water, and that this could rise to eight million by 2050 – one out of every four properties. One concern is that some areas will become uninsurable and thus uninhabitable; a government-backed scheme to provide insurance to vulnerable properties ends in 2039. In Tenbury Wells in Worcestershire, hit by floods in 2019, 2020, 2023 and 2024, some properties are already uninsurable.

How will public health be affected?

As summers heat up, the CCC estimates heat-related deaths could exceed 10,000 a year by 2050 (the long-term average for England and Wales is 634, but the hot summer of 2022 caused more than 4,500 heat-related deaths). A warming climate will also change disease patterns, creating a welcoming environment for food-borne bacterial infections such as salmonella and campylobacter, and for insect-borne diseases such as malaria and Lyme’s.

How can Britain adapt?

For the period to 2030, Labour has allocated more than £59 billion to achieving net-zero emissions. It spends far less on adaptation, though significant pledges have been made. Nine new industrial-scale reservoirs will be built by 2050 to address water shortages; and a £2.7 billion boost given to the £1 billion spent on flood defences annually. In 2022, the government identified 56 climate risks, from loss of native species to political instability abroad, and 12 opportunities (notably, the potential benefits of higher winter temperatures, and the growth of tourism). More than half of the risks were judged as needing “more action” in the near term.