The Committee on Climate Change has issued “unequivocal advice” to the government not to carry forward an emissions surplus from the second carbon budget to subsequent accounting periods.
In a letter to energy and clean growth minister Claire Perry, the chair of the climate watchdog, Lord Deben, said rolling over the surplus would make it “more difficult and expensive” for the UK to meet its long-term emissions targets.
“The committee’s unequivocal advice is that surplus emissions from the second carbon budget should not be carried forward,” he wrote.
“The carbon budgets have been set to meet the 2050 target at lowest cost, and on the basis that there would be no carry forward of surplus emissions from earlier periods.”
The letter was sent shortly after the government published the final figures for greenhouse gas emissions during the second carbon budget spanning the period of 2013 to 2017. The emissions covered by the budget were 384 megatonnes below the cap of 2,782 megatonnes of carbon dioxide equivalent (MtCO2e).
In an assessment document accompanying the letter, the Committee on Climate Change said surpluses should only be rolled over if they are the result of early policy delivery, if carrying them forward would not undermine progress towards meeting subsequent targets, or if loosening the following budgets would avoid incurring excessive costs.
But Lord Deben said the surplus in question has not emerged due to the government’s efforts to combat climate change, which “failed to produce the expected reductions in emissions.” It is instead the result of “accounting changes in the EU Emissions Trading System (ETS) and the lasting effects of the recession”.
As traded emissions are not included in the UK’s carbon budgets, the net purchase of 105MtCO2e of ETS allowances from other EU countries added more than a third to the overall surplus.
Source: Committee on Climate Change
Lord Deben said the agreed carbon budgets are “already too loose compared to the cost-effective path for emissions reduction”, adding: “Carrying forward surplus emissions would further loosen carbon budgets, leading to unnecessary costs in meeting the long-term target.”
He concluded: “The aim should be to meet and outperform carbon budgets through actions to reduce emissions, rather than relying on statistical revisions which can go both up and down.
“The previous government confirmed their intention not to use surplus emissions from statistical accounting changes to meet carbon budgets. We welcome your confirmation in the house that it is your intention to meet the carbon budgets through domestic action.”