Zero Carbon Sooner — Revised case for an early zero carbon target for the UK | Paper

Summary

This paper is an update of an earlier briefing note, revised to take account of new findings from the IPCC’s updated 6^th Assessment Report (AR6). The broad aim of the paper is to establish how soon the UK should aim for (net) zero carbon emissions. The paper first derives a ‘fair remaining carbon budget’ for the UK. It then analyses a variety of emission pathways and target dates for their adequacy in terms of remaining within this budget.

A first key finding is that a target date for zero carbon is not sufficient in itself to determine whether the UK remains within its carbon budget. Policy must specify both a target date and an associated emissions pathway. A second key finding is that the sufficiency of these targets and pathways depends crucially on whether emissions are accounted for on a ‘territorial’ basis or on a ‘consumption’ basis.

For a linear reduction pathway not to exceed the remaining carbon budget the net zero target year would have to be between 2027 and 2032, depending on the accounting framework. For a target year of 2050, the average rate of emission reductions must lie in the range 17-27% if the UK’s fair budget is not to be exceeded. As measured on a consumption basis, these rates would require absolute reductions approaching 95% of current carbon emissions as early as 2030. Consequently, this paper argues in favour of setting a UK target for net zero carbon emissions no later than 2035, with a maximum of around 5% of the mitigation effort achieved through negative emission technologies.