By Roger Harrabin
BBC Environment Analyst
The rest of the economy may have to make space for aviation emissions
The UK may have to cut emissions of greenhouse gases by 90% by 2050 so the aviation sector can continue to grow.
That is the warning from the government's official climate advisers, the Climate Change Committee (CCC).
It would mean even bigger cuts than the 80% drop on 1990 levels already planned for households and industry in Britain.
But the committee also says global aviation emissions should be capped during the forthcoming Copenhagen climate talks.
The committee was asked by government to advise on what should be done about emissions from aviation.
In a letter to the Transport Secretary Lord Adonis and the Climate Secretary Ed Miliband, the committee says the aviation industry will have to cut emissions from planes back to their 2005 level by 2050.
That is much more permissive than the overall UK target of cutting emissions 80% on 1990 levels by 2050.
The failure of aviation to play its full part could mean that the rest of the economy has to reduce its emissions by 90% instead of 80%.
This 90% target is so ambitious that it might be easier for some sectors to make the leap to zero carbon emissions rather than trying to whittle down pollution decade by decade.
And some analysts think this might be an easier and cheaper approach than reaching a 90% cut in stages.
The committee members see alternatives.
Planes, they say, might use biofuels or aviation might cut emissions below 2005 levels through new technology.
Plane operators might also be able to buy emissions permits in international emissions trading.
But all of these options carry difficulties of their own.
Biofuels compete with crops for land and are already in demand for fuelling cars.
It looks to be a huge task for aviation to restrict emissions to 2005 levels, even without trying to go further.
And the emissions trading system in which rich countries pay poor ones to clean up their pollution may prove to be a stop-gap solution which could be defunct by 2050.
The CCC's recommendations are designed to reduce aviation emissions in line with a global reduction in emissions of all greenhouse gases of 50% by 2050.
It says that, if left unchecked, global aviation could account for 15-20% of all the manmade CO2 produced in 2050.
The committee advises that:
- All CO2 emissions from aviation should be capped, either through a global aviation deal or by including international aviation emissions in national emission reduction targets;
- Any international agreement to reduce emissions should be no less than the EU's target of a 5% reduction in net emissions from 2013-2020;
- Emissions allowances for aviation in the EU emissions trading scheme, says the CCC, should be fully auctioned to prevent windfall profits for airlines;
- Funds should be found for radical innovation in engine, airframe and fuel technology;
- Additional non-CO2 gases from aviation are contributing to global warming. The effects of these should be addressed within a global deal on aviation.
The CCC's Chief Executive David Kennedy said: "It is vital that an agreement capping global aviation emissions is part of a Copenhagen deal.
"We are calling for a cap that would not require people to fly less than today, but would constrain aviation emissions growth going forward."
The right-leaning think-tank Policy Exchange recently proposed that world production of sustainable biofuels should be diverted from cars to planes in order to overcome the lack of current breakthrough technologies in aviation.
Greenpeace climate change campaigner Vicky Wyatt said: "Any government of whatever stripe, were they to follow the committee's advice, would find it almost impossible to build a third runway at Heathrow.
"We already fly more than any other nation on Earth and other industries such as the power sector would have to reduce their emissions even further to create room for the aviation sector to grow even more. Electricity consumers could end up footing the bill.
"The only way to make the deep cuts in aviation emissions that we need is to stop building new runways, like the one at Heathrow."
Secretary of the CCC, David Kennedy, told the BBC it would discuss Heathrow as part of a deeper review on aviation due later in the year, but that it was by no means clear whether or not it would make policy recommendations on the expansion of the airport.
Meanwhile, the Times newspaper has reported that passengers will face new taxes to halt the rise in aviation pollution, but Mr Kennedy said under the current EU emissions trading scheme (EUETS), supported by the UK government, taxes would rise very gently.
In the first decade they would be barely noticeable, he said: "Under the current regime it is likely that in about 30 years taxes would have risen sufficiently to make us think about whether we want to take that third long-haul flight of the year."
The trading scheme currently proposes giving airlines 85% of their emissions permits free of charge.
The committee recommended that airlines should have to buy all their permits at auction to prevent them making a windfall profit.
Mr Kennedy said there was no evidence that this would double the cost of tickets for passengers.
When power firms were given free permits under the EUETS they made billions of pounds in windfall profits by passing on the notional market cost of the emissions permits to consumers even though they had not had to pay for the permits themselves.
Mr Kennedy declined to comment on whether the committee would make recommendations on further aviation taxes in its forthcoming review, but the BBC understands that as car taxes are much higher per tonne of CO2 produced the committee may compare the taxes on planes and cars.
The shadow energy and climate change secretary, Greg Clark said: "The Climate Change Committee was established by the Climate Change Act... to give advice to the government, so its recommendations need to be taken seriously.
He added that the government's policy on aviation would "lack credibility" as long as it continued to support a third runway at Heathrow.