A new climate change flood map has predicted three million homes could become unsellable if the UK does not hit its emissions target.
The government has set a net-zero emissions target for 2050, which will require drastic changes in the way people travel, heat their homes and consume electricity.
If the goal is missed, one in ten homes (3,066,318) will be at risk of flooding due to heavier rain and rising sea levels, according to locations intelligence provider Gamma which has mapped at-risk areas.
This would put one in five homes in Portsmouth in danger of flooding by 2050.
A third of houses and commercial buildings in Great Yarmouth will also be under threat, meaning homeowners may not be able to sell their properties for the next 30 years.
The report adds that around 14,000 properties further inland in Kensington and Chelsea will also face a threat of flooding.
Hotter and drier summers may also cause cracks in buildings as the soil dries unevenly.
The number of properties at risk of subsidence in Swindon could jump from 1% to 81%.
The Gamma report comes as Boris Johnson set out his ambition this week for a green revolution he hopes will force countries to drop their addiction to fossil fuels and commit to net-zero carbon emissions.
Next week the UK hosts the COP26 UN climate talks in Glasgow, which aim to strengthen global action on climate change
In 2019, Britain became the first member of the Group of Seven major industrialised economies to set a net-zero emissions target for 2050.
The strategy is a series of long-term promises, some with caveats, to shift the world's fifth-largest economy towards green technologies, including moving to clean electricity and low-carbon heating in British homes.
It aims to secure 440,000 jobs and unlock £90 billion of private investment by 2030.
It also aims to help Britain gain a competitive edge in low-carbon technologies such as heat pumps, electric vehicles, carbon capture and storage and hydrogen.
The government targets being powered entirely by clean electricity, "subject to security of supply", by 2035.
It aims to have 40 gigawatts (GW) of offshore wind power by 2030 and 1 GW of floating offshore wind.
As of the end of last year, renewables accounted for around 40% of total electricity generated in Britain, with wind energy supplying about 24% of that.
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