A UK Conservative Party policy document puts the cost of the transition to net zero at almost twice the amount calculated by the government's official climate policy adviser. According to a Carbon Brief factcheck, the £957 billion figure cited in the document appears to stem from double counting data in a spreadsheet. The Climate Change Committee's (CCC) actual estimate in 2020 was £478 billion for the period 2020–2050.
The Conservative document, titled “Right Way”, was published in October 2026 and sets out policy proposals emphasising common sense and competent government. It argues that people want a government capable of solving the problems it takes on and that sophisticated modelling should not replace political judgement. The same section questions various estimates of the cost of the climate transition and attributes the incorrect £957 billion calculation to the CCC.
The CCC's 2020 figures separated additional investment from operating cost savings. The investments included low-emission electricity generation, heat pumps and electric vehicles, among other things, with total capital expenditure of about £1.38 trillion over 30 years. These were offset by operating savings of about £900 billion. Taking both figures into account, the net additional cost of the transition came to £478 billion.
The spreadsheet contained annual investment and operating costs by sector, as well as a separate row showing the combined annual totals. As Carbon Brief explains, adding up all these rows counts the same costs and savings twice. The result is £957 billion. This appears to be the source of the figure that ended up in the Conservative document, even though its reference points to the CCC's official report, which contains no such estimate.
When it published the calculations in 2020, the CCC said the net cost amounted to less than 1% of GDP over the 30-year period. The committee also argued that the substantial investments would deliver savings by reducing fossil fuel imports. By its own estimate, they would increase GDP by about 2% overall. Its assessment therefore included both additional expenditure and expected economic benefits.
In 2025, the CCC substantially revised its calculations, mainly because of falling electric vehicle costs. For the period 2025–2050, it calculated investment costs of £670 billion and operating savings of £562 billion, giving a net cost of £108 billion, below 0.2% of GDP. Earlier in 2026, the committee also said that reaching net zero would cost less than a single sharp rise in fossil fuel prices. It also estimated that the transition would deliver benefits worth £110 billion a year.
The earliest online appearance of the £957 billion figure found by Carbon Brief was in an article by retired engineer David Turver in the Spectator on 12 January 2026. The following day, he repeated the figure in a report for the Institute of Economic Affairs, citing chart 5.3 of the CCC's 2020 report. However, the spreadsheet data corresponding to that chart give a net cost of £478 billion. Carbon Brief believes Turver mistakenly added the annual totals row as well.
Turver's report also fuelled inaccurate headlines that put the transition cost at £7.6 trillion or even £9 trillion. According to Carbon Brief, these figures relied, among other things, on the implicit assumption that fossil fuels and the cars, boilers and power plants that use them have no cost. This assumption affects the comparison between the costs of the transition and those of continued fossil fuel use.
In March 2026, the incorrect £957 billion figure was repeated by the Great British Think Tank, which says it sources every number from official public bodies. It subsequently appeared in the Conservatives' “Right Way”. The factcheck highlights how a possible data handling error can move from articles and reports into policy documents while retaining a seemingly valid reference. In this case, the official source supports a substantially lower cost than the one attributed to it.
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