Carbon budget for 2030 – but still equivocation over aviation

10th December, 2010

The Committee on Climate Change (CCC) has recommended a ‘budget’ for the period 2026-2030: “An Indicative 2030 target to reduce emissions by 60% relative to 1990 levels (46% relative to 2009 levels).” 

 CCC says that this target for 2030 is consistent with the 2050 target of 80% cuts (relative to 1990). Details of the report may be found on the CCC web site. 

 However, international aviation continues to confound these figures.

AEFs welcomes the CCC’s clear statement that international aviation must be included in the 2050 target: “It is vital that the UK’s target includes the UK’s contribution to international aviation and shipping (IA&S) emissions (and .. should in future be included in the legally binding carbon budgets).”  

However there is still equivocation on the budget for 2030. CCC says: “Our approach in this report is to reflect, but not explicitly include, international aviation and shipping emissions.”

The reason is said to be: “ .. because of complexities around methodologies for inclusion ” However, the report goes on to say:“EU ETS data on international aviation emissions will not be available until 2011; subject to data availability and accuracy, it is likely that there then will be an appropriate basis for inclusion in the net carbon account.”

CCC recognises the impact of international aviation emissions: “For example, in the context of the 2050 target, lower expected abatement in international aviation and shipping must be made up by higher abatement in other sectors of the economy.”  ..

“Our assessment of UK contributions to global trajectories assumes a 2050 target to reduce greenhouse gas emissions by 85% excluding international aviation and shipping. This equates to an 80% reduction in total greenhouse gas emissions where these sectors are included based on bunker fuels estimates and where their emissions are at 2005 levels in 2050.”

Increasing the target for other sectors to 85% to accommodate aviation and shipping is a significant and potentially very controversial recommendation. But the real impact of aviation may be even greater than CCC admits.

Firstly, CCC assumes that aviation emissions will be no higher at 2050 than at 2005. This was a target from the last government, introduced to appease opponents of a third runway at Heathrow. However, estimates by the Department for Transport show a massive rise of 56% just between 2005 and 2030. The present government has not confirmed the target.

Secondly, the targets and budgets do not appear to allow for the non-CO2 emissions from aviation. The Climate Act and the CCC’s budgets are only for greenhouse gases included under the Kyoto Protocol.  Aircraft emit water vapour and nitrogen oxides which are powerful greenhouse gases when emitted at altitude but which are not included under the Kyoto Protocol.  These are thought to have as great an effect as CO2.  And if formation of cirrus cloud is allowed for, the effect may be much greater.