The UK Conservative party's "Right Way" document claims that reaching net-zero will cost close to £1tn, citing a Climate Change Committee (CCC) estimate of £957bn. According to a Carbon Brief factcheck, this figure is wrong: the CCC's 2020 estimate was exactly half that amount, at £478bn. The error appears to come from a spreadsheet blunder that counted costs and savings twice.
The mistaken figure traces back to a January 2026 article and report by David Turver, who added up all the numbers in a CCC spreadsheet without noticing that it already included a line for annual totals. This double-counting produced the £957bn figure, which was later repeated by the Great British Think Tank and then adopted in the Conservative document.
The CCC has since revised its estimates. In 2025, it put the net cost of net-zero at £108bn over 2025-50, or less than 0.2% of GDP, largely because of falling electric vehicle costs. The committee has also said that cutting emissions would cost less than a single fossil-fuel price shock and would bring benefits worth £110bn per year.