While advisers to the UK Government have proposed an emissions cap on aviation in order to meet 2050 carbon dioxide targets, aerospace industry representatives claim this target will already be met by the country's 'Sustainable Aviation' initiative.
In a letter to the UK's transport and energy secretaries, the Climate Change Committee lays out advice on a framework to reduce aviation emissions.
It says global aviation could account for 15-20% of all permitted carbon dioxide emissions in 2050, but says that aviation will not be able to deal with the "vast majority" of these reductions in the long term through purchase of emission allowances or offset credits.
"Ideally all global [carbon dioxide] aviation emissions would be capped," says the letter, although it adds that, in practice, caps would probably focus on developed countries in the interim.
The committee says that cutting gross aviation emissions in 2050, when combined with 90% emission cuts in other sectors, will achieve the economy-wide 80% reduction required in the UK.
It is recommending that an international agreement should plan to limit gross aviation emissions in 2050 to no more than 2005 levels, resulting in aviation emissions accounting for up to 25% of total allowed emissions in developed countries in 2050.
But the Society of British Aerospace Companies says the carbon dioxide 'roadmap' included as part of the UK's 'Sustainable Aviation' initiative already sets out how the industry will meet a three-fold increase in passenger demand while keeping carbon emissions at 2000 levels.
"This demonstrates that the more pessimistic forecasts around greater contributions from other sectors will not be necessary," says a spokesman for the organisation. He adds that the aerospace industry is "already keen" to see an emissions cap through a global version of the European Union's emissions-trading scheme.
The committee supports the inclusion of aviation emissions in the EU scheme from 2012, but says emission allowances should be fully auctioned to prevent airlines' benefiting from "windfall profits" which might result from free allowance allocation.
It also says that sources of funding - such as the possibility of using auction revenues - need to be agreed for research and development into the new technologies required to cut emissions, as well as for processes to adapt to climate change.
SBAC says that the use of revenues from the EU's emissions-trading scheme to finance research is a "very good idea". Discussions aimed at firming these proposals are set to take place at the key Copenhagen climate summit from 6 December.