DECARBONISING Britain by 2050 will cost £1.4trillion — the equivalent of £50,000 a household.
Tearing out gas boilers, cleaning up industry and switching to electric cars will all carry big price tags, a shock Treasury watchdog report warns.
Chancellor Rishi Sunak would have to impose carbon taxes to make up for the loss of fuel duty and other hits to its coffers when fossil fuels are ditched, the 242-page Office for Budget Responsibility study predicted.
Boris Johnson has vowed to reach Net Zero emissions by 2050 in a global bid to halt climate change.
But the OBR forecasts the bill will be £1.408trillion over 30 years — or £50,647 for every UK home.
The OBR reckons the state will have to find £344billion towards the cost.
Yet it insisted a large chunk of the bill — £1.086trillion — will be covered by savings as cars and homes become more energy efficient and cheaper to run.
That would mean a typical household playing £11,583 in three decades.
But the OBR warned doing nothing on climate change would have “catastrophic economic consequences”.
Floods and other extreme weather disasters would wreak economic damage.
A scramble for resources globally might also spark war and mass migration that could harm Britain.
And the OBR said that acting sooner rather than later would be more cost-effective in the long run.