The Conservative Party's new 100-page policy manifesto, The Right Way, contains a numerical error so elementary it would fail a first-year accounting class. The document claims the Climate Change Committee estimated net zero costs at £957bn. The actual figure in the CCC's Sixth Carbon Budget is £478bn. Someone added the column totals into the column sums, doubling the number. The error was spotted by Carbon Brief, which traced the inflated figure back through a chain of copy-paste: from the CCC's own spreadsheet, through a report by the Institute of Economic Affairs (a right-wing think tank), into the Spectator, and finally into the Tory conference document. At no point in this chain did anyone apparently check the original source. The CCC has publicly said it does not recognise the number and has offered to walk Badenoch through its actual advice. The CCC's most recent analysis puts the expected cost of reaching net zero by 2050 at roughly £110bn total, or about £4bn per year — 0.2% of GDP. The gap between £110bn and the Tories' £957bn claim is not a rounding error. It is the difference between a manageable investment and a case for abandoning climate commitments entirely, which is precisely the conclusion the document draws. The document is explicitly modelled on Margaret Thatcher's 1976 policy paper The Right Approach, and Badenoch's foreword emphasises her engineering background and the importance of accurate diagnosis. The irony is structural: the party's central argument for scrapping net zero rests on a number that is provably wrong, cited without verification, in a document whose stated purpose is analytical rigour. The provenance chain matters. The IEA report appears to have made the original error, the Spectator amplified it, and the Conservatives institutionalised it in party policy. This is how bad numbers harden into policy orthodoxy — not through deliberate fabrication, but through a chain of trust where nobody returns to the primary source. This is not a minor footnote error. The inflated cost figure is the load-bearing beam of the Tories' argument for abandoning net zero. Remove it, and the policy rationale collapses to a question about whether £110bn over decades — a fraction of annual NHS spending — justifies walking away from the UK's most significant long-term emissions framework. The Conservatives and Badenoch's office were contacted for comment. The CCC's offer to brief Badenoch on its actual numbers remains open.
