In the absence of a zero-carbon plane, long-term growth in aviation demand cannot continue unchecked, says UK's climate adviser
(photo: Heathrow Airport)
Mon 18 Feb 2019 – The largest contribution to reducing long-term aviation emissions will come from new technologies and aircraft designs, but in the absence of a true zero-carbon plane, steps will be required to limit growth in demand, says the UK government’s advisory Committee on Climate Change (CCC). In a letter to the Secretary of State for Transport, the Committee’s Chairman, Lord Deben, said UK aviation emissions have more than doubled since 1990, while emissions for the economy as a whole have fallen by around 40%. The government has agreed with the CCC’s planning assumption that emissions should be around their 2005 level – 37.5 MtCO2e – by 2050, but the letter urges that this should be met on the basis of actual emissions and not by relying on international offset credits. Speaking at the RAeS Greener by Design conference in November, a CCC official said the target will have to be revisited in the light of the Paris Agreement.
The CCC letter is an initial response to the ‘Aviation 2050 Strategy’ green paper and consultation recently announced by the UK government (see article). The current 2050 target is to reduce economy-wide GHG emissions by at least 80% from 1990 levels and the government has set in place legally binding carbon budgets to achieve the goal. The Committee has been tasked with providing advice on the implications of the higher ambition of the Paris Agreement, including when net-zero emissions can be achieved.
“A stronger UK target would require more effort from all sectors, including aviation,” said the letter. “We intend to provide an updated view on the appropriate long-term ambition for aviation emissions within our advice on the UK’s long-term targets.”
Deben said a report would be published in the spring, which would be followed by a setting out of implications for the government’s final aviation strategy white paper due to be published in the summer.
The CCC said achieving the present aviation emissions target for 2050 would require contributions from all parts of the aviation sector, including from new technologies and aircraft designs, improved airspace management and airline operations, and use of sustainable fuels. The white paper should set out a clear strategy to ensure technology solutions “are developed and brought to market in a timely fashion,” it recommends.
The Committee remains cautious about the prospect for aviation biofuels and is holding to its 2009 forecast of up to 10% biofuel use in 2050, given what it sees as uncertainty about sustainable biomass supply and cost-effectiveness. It says production will likely need to be in conjunction with carbon capture and storage (CCS) to be competitive with competing uses for biomass in, for example, electricity generation or hydrogen production.
It advises the government not to plan for high levels of aviation biofuel use, therefore, but does recommend in the period to 2030 that government policy should aim to develop a market for such fuels produced in “genuinely CCS-ready facilities” through the national 2030 Renewable Transport Fuel Obligation programme.
The Committee’s letter also welcomes the UK commitment expressed in the green paper to negotiate in ICAO a long-term goal for international aviation emissions that is consistent with the Paris Agreement, noting the CORSIA scheme’s end date of 2035 and the agreement last year by the global shipping sector to reduce its GHG emissions by at least 50% below 2008 levels by 2050. “A new long-term objective would provide a strong and early signal to incentivise the investment in new, cleaner technologies that will be required for the sector to play its role in meeting long-term targets,” it added.
The UK’s overall 2050 target to reduce emissions by 80% compared with 1990 includes emissions from international aviation, which have not so far been included in the carbon budgets. With a lower goal for aviation, this implies for the rest of the economy, emissions will actually have to fall by 85% to meet the 2050 target.
“So aviation in some sense is in a privileged position,” Adrian Gault, the Committee’s Chief Economist, told the Royal Aeronautical Society’s Greener by Design conference in November.
“The 80% reduction target was based on a UK contribution to keep the global temperature rise to around 2 degrees C, but the Paris Agreement calls for well below 2 degrees and to pursue efforts to limit it to 1.5 degrees.
“We will therefore be revisiting the 80% target and whether it is strong enough. This will include us looking again at the planning assumption for aviation, which allows for a 60% growth in passenger demand. The overall implication is that targets will only get tighter in the light of Paris.”
The CCC commissioned a report from aviation experts looking at plausible scenarios for technology improvements in new aircraft entering the fleet, how quickly they can be introduced and at what cost. This analysis will be included in the spring report to the government. The Committee will also review the implications of the CORSIA carbon offsetting scheme for international aviation and the effect of other GHGs on global warming, said Gault.