Conservatives’ £957bn net-zero estimate challenged over apparent double counting

The Conservatives’ case for abandoning the UK’s 2050 net-zero target faces a numerical challenge after the Guardian reported on 9 October that a policy document promoted by Kemi Badenoch at the party’s Birmingham conference overstated an older cost estimate by nearly £500bn. The report concerns the projected economic cost of the transition, rather than money already spent.

The disputed figure appears in The Right Way, a 100-page conference document. According to the Guardian, it attributes a £957bn estimate to the Climate Change Committee’s 2020 Sixth Carbon Budget, while the relevant figures actually total £478bn. The committee told the newspaper it did not recognise the higher number.

How the £957bn net-zero figure is challenged

The Guardian quotes the Conservative document as saying: ‘In 2020, the Climate Change Committee (CCC) estimated that its route to net zero would cost £957bn.’ It reports that the document gives gross economic costs of £1.4tn, reduced to £957bn once savings are included.

The newspaper’s proposed explanation is that a spreadsheet calculation added individual figures and a row containing column totals, counting the same costs twice. Its reported £478bn total is approximately half the party document’s figure; the rounded numbers imply a difference of about £479bn.

A CCC spokesperson told the Guardian: ‘We don’t recognise this number.’ The spokesperson added that the committee had previously offered to meet Badenoch to explain its advice and that the offer remained open. The newspaper said it contacted the Conservatives and Badenoch’s office; the article contained no response from either.

Why the estimate matters for Conservative policy

According to the Guardian, the document uses the estimate in explaining the Conservatives’ decision to scrap the 2050 target, introduced under Theresa May. That is the party’s policy position: the report does not establish that the UK’s national target has been repealed.

The document also presents itself as a diagnosis of Britain’s problems. The Guardian quotes it as saying: ‘To fix a problem we must first have an accurate understanding of what is causing it.’ The reported discrepancy concerns the numerical basis offered for its net-zero position; it does not establish deliberate misrepresentation.

What the CCC’s newer £110bn estimate measures

The CCC’s Seventh Carbon Budget, published in February 2025, models a pathway covering 2025–2050. It estimates net costs of around £110bn, averaging about £4bn annually, or 0.2% of GDP. These are economy-wide estimates, rather than a government spending bill.

The model projects average annual investment of £26bn, offset by £22bn in operating savings. Annual savings are projected to overtake investment costs around 2041. Those savings are a future modelled outcome, dependent on the transition taking place, rather than benefits already realised.

The newer total cannot simply replace the older one in a like-for-like comparison. The CCC attributes its lower estimate to changed assumptions and methodology, as well as a different period that excludes 2020–2024. Gross investment, costs after operating savings and wider social benefits also measure different things.

How households and wider benefits enter the calculation

The CCC expects private investment to provide most funding, given suitable incentives. Public support can help distribute costs and pay for one-off building improvements. Households needing heating upgrades face upfront costs, and the committee says lower heat-pump bills depend on removing policy costs from electricity bills.

In supplementary analysis published on 11 March 2026, the CCC tested its proposed pathway against different scenarios using government Green Book guidance. It found net zero more cost-effective than continued fossil-fuel reliance in every scenario tested. That conclusion is conditional on its modelling.

The analysis estimates benefits at 2.2–4.1 times spending, with avoided climate damage the largest benefit: £40bn–£130bn in 2050. It also weighs potential gains from cleaner air, warmer homes, active travel and healthier diets against downsides including extra public-transport time and possible congestion associated with electric vehicles.