UK Conservative net-zero cost figure traced to spreadsheet double-count
A Conservative Party booklet claims the Climate Change Committee put the cost of net-zero at close to £1tn. The CCC's 2020 estimate was actually £478bn, later revised to £108bn, and the higher figure appears to result from adding combined annual totals twice in a spreadsheet. This double-counted both capital costs and operational savings.
The Conservative booklet “Right Way” cites the CCC’s 2020 advice as putting net-zero near £1tn. The CCC’s spreadsheet instead lists £1.38tn in extra capital spending and £0.90tn in operating savings across 2020–50, producing a £478bn net cost. A later CCC update cut the net figure to £108bn for 2025–50.
The £957bn number appeared online in January 2026, first in the Spectator and then in an Institute of Economic Affairs report. Both trace to a spreadsheet total that already combined annual CAPEX and OPEX, so adding every row counted costs and savings twice.
The discrepancy could affect public trust in political cost claims, especially among voters weighing net-zero affordability. It may also intensify scrutiny of opposition policy documents and the think tanks or commentators cited in them. If repeated, such errors could distort debate over climate spending, though the CCC’s lower revised estimates may help reframe net-zero as a modest net cost rather than a near-£1tn burden.