A new CO2 Standard strikes a balance between strength and achievability for aircraft produced after 2020

The agreement of a carbon dioxide (CO2) Standard by the 170 experts that form the Committee on Aviation Environmental Protection (CAEP) marks yet another milestone in the industry’s battle against climate change.

The standard is technically complex, but basically sets a fuel burn limit per flight kilometer during the cruise phase of flight. The limit is adjusted according to an aircraft’s range and payload while the aircraft’s performance is averaged out from three measurements taken at different points during the cruise phase.

The CO2 Standard focuses on the cruise flight performance as this is typically when the most fuel is consumed and the majority of CO2 is emitted. Once formally approved by the ICAO Council, the standard will apply to new aircraft from 2020 and to aircraft models already in-production from 2023.

A cut-off date of 2028 has been recommended for the production of any aircraft that does not meet the CO2 Standard. “It is particularly encouraging that the CAEP’s recommendation … responds so directly to the aircraft technology improvements, which States have forged consensus on at recent ICAO Assemblies,” says Olumuyiwa Benard Aliu, President of the ICAO Council. “Every step taken in support of ICAO’s full basket of measures for environmental improvement is an important one, and I am sure the Council will be deeply appreciative this latest CAEP achievement.”

Providing momentum

The CO2 Standard is an important tool that will complement the industry’s efforts to mitigate its environmental impact, including the anticipated global market-based measure (MBM).

Since 2009, airlines have spent $1 trillion on new fuel efficient aircraft and there are some 14,000 aircraft on order. Moreover, the Air Transport Action Group (ATAG) estimates that manufacturers, recognizing that environmental performance is a key competitive differentiator, are investing some $15 billion per year on efficiency research and development.

The results are evident. Fuel efficiency is moving in line with the industry’s self-imposed target of a 1.5% average improvement to 2020.This is driving the de-coupling of emissions growth (about 3%) from the growth in demand (5%) that the industry is satisfying.

The CO2 Standard will formalize the discipline of fuel efficiency improvements. As was the case with noise standards, it is expected that its stringency will ratchet up over time to further encourage achievable advances in technology.

Executive Director of ATAG, Michael Gill, says the standard will generate much-needed momentum. “The CO2 Standard is a milestone on the road towards this year’s ICAO Assembly and the discussion to deliver a robust global offsetting scheme with which we can cap growth in CO2 emissions from aviation from 2020,” he says. “This CO2 Standard places an obligation on the manufacturers and the market-based measure will do the same thing for airlines and other operators. Both steps are an integral part of the aviation sector’s plan for capping CO2 emissions from 2020 and then halving them by 2050, based on 2005 levels.”

“Air transport must support the sustainable development of economies while also dealing with our climate change responsibility,” he adds. “The agreed CO2 Standard and the global MBM we hope will be agreed at the ICAO Assembly in September will enable that to happen.”

Robust limit

Setting the standard required a delicate balance. It needed to be sufficiently challenging to make it meaningful. But, making it too stringent could have delayed implementation until the requisite technology was developed—a counter-productive move.

The major manufacturers welcomed the result. Boeing, for example, released a statement that said the CO2 Standard represents “real progress” beyond the substantial industry achievements to date. “The new standard is ambitious and will become part of the certification process applied to every airplane before delivery based on the ICAO schedule,” the statement continued. The proposed global standard will have the greatest impact on larger aircraft. Aircraft weighing over 60 tonnes account for more than 90% of international aviation emissions and typically these aircraft and the airlines that use them have access to the broadest range of emissions reduction technologies.

A balance also had to be struck between what is being reduced. Noise and other emissions are not decreased by the same technologies that can decrease CO2 emissions. Nitrogen Oxide emissions can go up in the hotter engine cores that decrease CO2. Clearly, the scales could tip too far in one direction.

Given these labyrinthine considerations, Gill says the CO2 Standard represents, “an appropriate level of regulatory pressure while allowing the marketplace to determine the makeup of the global aircraft fleet.”

Next generation

In-service aircraft do not have to meet the Standard. While retrofitting is a common enough occurrence, these modifications tend to be limited to smaller items such as wingtips. Changing engines or making substantial alterations to the airframe of in-service aircraft is a far more significant undertaking and prohibitively expensive.

The goal of the process is rather to ensure that when the next generation of aircraft enter service, there will be guaranteed reductions in international CO2 emissions.

Once the CO2 Standard is formally adopted at ICAO level, it will be implemented by national civil aviation authorities around the world and will be part of the rigorous certification process all new aircraft must meet before entering service. The Standard will be reviewed periodically to increase its stringency in line with technology advancement.

“The CO2 Standard does not solve aviation’s climate challenge on its own, but it is an important element in our comprehensive strategy for tackling carbon emissions,” concludes Tony Tyler, IATA’s Director General and Chief Executive Officer. “This CO2 Standard proves that the industry and the world’s governments are working together to find a sustainable future for aviation.”