There is no longer any reason to exclude international aviation and shipping emissions from carbon budgets, the Committee on Climate Change (CCC) has told the government in a statutory advice document.
 
The UK’s existing carbon budgets should be increased to allow for emissions from both sectors, says the advisory committee's report. “Failure to do so could result either in increased costs and risks of meeting carbon budgets, or in accepting higher risks of dangerous climate change."
 
Under the Climate Change Act 2008, the government must cut emissions by at least 80% below 1990 levels by 2050. A framework of five-year carbon budgets was established to help achieve this.
 
The budgets and targets cover all UK greenhouse gas emissions, except those from international shipping and aviation. These were initially excluded due to methodological and accounting difficulties.
 
Taking account of the CCC’s statutory guidance, the government must either include these sectors by the end of this year or explain to parliament why it has not done so.
 
While existing carbon budgets do not formally include international shipping and aviation emissions, they were designed to put the UK on a trajectory consistent with the 80% reduction target, even when these two sectors are factored in. As such, emissions from the sectors should be added to – not fitted within – existing budgets.
 
This current approach of “assuming” but not legislating for the inclusion of international aviation and shipping “lacks legal underpinning and should now be formalised”, says the CCC. Including these sectors now would be “the most transparent, comprehensive and flexible approach”.
 
The complexities that previously excluded international aviation and shipping from the carbon budgets and targets “no longer exist”, it says. These related to the design of the EU emissions trading scheme (EU ETS) for aviation and difficulties in assigning international shipping emissions to specific countries.
 
But aviation has now been brought within the EU ETS (ENDS Report, October 2011) and the CCC has undertaken further analysis on methodological accounting options for shipping (ENDS Report, November 2011).
 
The report recommends that 30.5 million tonnes of carbon dioxide per year should be added to Britain's second, third and fourth carbon budgets (covering the period 2013-27) for international aviation. This is the UK’s share of the EU ETS cap, based on all departing flights, and is equivalent to 5.5% of all UK CO2 emissions in 2011.
 
For international shipping, about 9MtCO2 per year should be added to UK budgets, initially on a bunker fuel basis but moving to an ‘activity-based’ methodology “once this is sufficiently developed and agreed internationally”, says the report. That is equivalent to 1.6% of all UK emissions in 2011.
 
The CCC says this should be done now to provide a clear basis for setting the fifth carbon budget for 2028-32; preparatory work for this budget will begin in 2014.
 
The report also adds 0.3Mt of carbon dioxide equivalent for international aviation and 0.1MtCO2e per year for shipping, to cover the small amount of other greenhouse gases regulated under the Kyoto protocol, such as methane and nitrous oxide (see table).

The report also adds 0.3Mt of carbon dioxide equivalent for international aviation and 0.1MtCO2e per year for shipping, to cover the small amount of other greenhouse gases regulated under the Kyoto protocol, such as methane and nitrous oxide (see table). Other climate effects from the two sectors that do not fall under Kyoto, such as contrails, should be “further researched, closely monitored and reduced where possible”.

Other climate effects from the two sectors that do not fall under Kyoto, such as contrails, should be “further researched, closely monitored and reduced where possible”.
 
Including international aviation and shipping in carbon budgets and targets would involve no additional cost beyond the 1-2% of GDP in 2050 accepted by parliament when the Climate Change Act was first legislated, the report says.
 
This is because no additional effort is required for aviation beyond the EU ETS, for shipping beyond the International Maritime Organization’s (IMO) Energy Efficiency Design Index or for other sectors beyond that implied by current carbon budgets.
 
The report says international aviation emissions should return to 2005 levels by 2050, a target set by the previous Labour government. Based on the CCC’s ‘likely’ scenario, whereby emissions reductions are delivered through 0.8% annual efficiency improvements and 10% biofuel use, this would allow demand to grow by 75% from 2010 levels.
 
For international shipping, the report says emissions should fall to 6MtCO2 per year in 2050, about a third below 2010 levels.
 
This reflects the CCC’s central demand and abatement scenarios and should be relatively unproblematic, given that larger ships, technological improvements, operational measures and increased biofuel and liquefied natural gas use could reduce the sector’s carbon intensity by 65% by 2050.
 
Finally, the report says that its proposals are consistent with the principle that efforts should be made at global or EU level. However, it identifies a number of challenges in developing international frameworks and makes a series of further recommendations.
 
Government should continue to support the EU ETS, it says, while working with other countries to agree a global mechanism for reducing aviation emissions.
 
It should also support the development of market-based measures by the IMO. If these are not “forthcoming” – which they have not been (ENDS Report, March 2011) – government should push for the inclusion of international shipping emissions within the EU ETS.
 
And it should support technology development towards more efficient aeroplane and ship design, as well as advanced biofuels.
 
Launching his last report before stepping down as CCC chairman, Lord Adair Turner said: “This report makes a recommendation which, if now accepted by government and parliament, will complete the UK statutory framework.”

Please note this article has been republished with the kind permission of the ENDS Report.