A recent policy booklet published by the UK’s opposition Conservative Party features a prominent financial figure regarding the "cost of net-zero" that appears to have been inflated by a factor of two due to an underlying spreadsheet calculation error.
The policy document, titled "The Right Way" and framed as a "common sense" approach to governance, argues that the public ultimately desires a government competent enough to solve the problems for which it assumes responsibility. Within a section cautioning that sophisticated economic modeling should never serve as a substitute for grounded political judgment, the document takes aim at various official estimates concerning the price tag of transitioning the United Kingdom to a net-zero carbon economy.
However, in criticizing these projections, the Conservative publication asserts that the government’s official independent adviser, the Climate Change Committee (CCC), had previously pegged the total cost of reaching net-zero at nearly £1 trillion. Specifically, the booklet states that in 2020, the CCC estimated its designated route to net-zero would total £957 billion.
In reality, the official CCC figure published in 2020 was exactly half that amount—£478 billion. Furthermore, the committee released a revised estimate of £108 billion last year, largely driven by the rapidly falling costs associated with electric vehicles and advancing clean technologies.
The origin of the Conservative Party’s erroneous £957 billion figure can be traced back through a trail of think-tank reports and online commentary that inadvertently double-counted financial data from a 2020 CCC spreadsheet.
Spreadsheet Error and the Paper Trail
The root of the miscalculation lies in a detailed spreadsheet released by the CCC in December 2020 alongside its advice for the UK’s sixth carbon budget. The spreadsheet included a comprehensive table outlining the additional capital investments required to construct a net-zero economy, spanning everything from low-carbon electricity generation infrastructure to domestic heat pumps and electric vehicles.
These extra capital expenditures, identified in the data as "CAPEX," aggregated to a total of £1.38 trillion over the thirty-year period between 2020 and 2050. These costs were evaluated alongside projected operational savings, categorized as "OPEX," which totaled £0.90 trillion over the same timeframe. When balancing the capital expenditures against the operational savings across the 2020 to 2050 window, the combined net figure came to £478 billion.
Alongside the annual sectoral figures for CAPEX and OPEX, the CCC spreadsheet also included a summary line providing combined totals for each individual calendar year. The error occurred when this dataset was re-analyzed elsewhere, and someone mistakenly summed all of the annual totals together while also including the underlying component numbers. This effectively resulted in the operational savings and investment costs being counted twice, doubling the net total to £957 billion—the exact figure that eventually found its way into the Conservative Party’s official policy booklet.
When the CCC originally published its findings in 2020, it emphasized that the net cost of £478 billion amounted to less than 1% of the United Kingdom’s gross domestic product (GDP) over the course of three decades. The committee noted at the time that the substantial investments required would not only yield ongoing savings through reduced fossil-fuel imports, but would also provide an overall boost to GDP of approximately 2% by stimulating green industries and innovation.
Subsequent updates from the advisory body have only underscored these shifting economic dynamics. In 2025, the CCC updated its investment cost and operating savings projections to £670 billion and £562 billion respectively, yielding a revised net total of £108 billion for the 2025 to 2050 period—representing less than 0.2% of GDP. Earlier this year, the committee reiterated that achieving net-zero emissions would ultimately cost less than enduring a single major fossil-fuel price shock, while delivering wider environmental and economic benefits valued at £110 billion annually.
Despite these clear, publicly available clarifications from official bodies, the inflated £957 billion figure entered circulation through external publications before being adopted by political actors. The earliest known online reference to the erroneous total appeared in January 2026 in an article published by The Spectator, authored by retired engineer and self-described energy analyst David Turver.
Just a day after that article was published, the same mistaken figure was repeated by Turver in a formal report prepared for the free-market Institute of Economic Affairs (IEA). While Turver’s report cited specific supporting charts from the CCC’s 2020 carbon budget advice, the underlying spreadsheet data for those charts totaled only £478 billion. By adding up every line item in the spreadsheet without accounting for pre-calculated annual totals, the analysis inadvertently doubled the final sum.
The ripple effects of this methodological oversight extended beyond domestic policy debates. Turver’s report also served as the basis for several other exaggerated figures circulating in media and commentary, including claims that net-zero would cost anywhere from £7.6 trillion to £9 trillion. These larger figures relied on implicit assumptions that essential infrastructure items—such as fossil fuels, existing vehicles, home heating boilers, and power plants—would carry zero residual value or cost.
In March 2026, the £957 billion figure was reiterated in a publication by the Great British Think Tank, an organization whose stated motto focuses on data over rhetoric and claims that all figures are strictly sourced from official public bodies. By October 2026, the figure had transitioned from third-party research into formal political strategy, appearing directly within the Conservative Party’s "Right Way" policy booklet as a central argument against current climate economics.
