Yesterday's agreement on carbon offsets at the ICAO conference in Montreal was hailed as aviation's "Paris moment" by council president Olumuyiwa Benard Aliu.

ICAO countries have committed to the Carbon Offset and Reduction Scheme for International Aviation (CORSIA), bringing an end to three years of tough negotiations following the UN body's last triennial meeting.

The 190 members are now tied to achieving carbon-neutral aviation growth against a benchmark level of their average 2019-2020 emissions, via a staggered introduction beginning in 2021. Countries such as China, Germany, the UK and the USA have committed to join the scheme from the start.

A pilot period will last from 2021 until 2024, followed by a "first phase" from 2024 to 2026. Then, from 2027 to 2035, the measures are due to become mandatory for all ICAO members, with a few exceptions for smaller states and developing countries.

If a country exceeds the benchmark level once it is part of the scheme, it will be required to offset the extra CO2 emissions through offset credits or allowances from emissions-trading schemes.

During the scheme's lifespan, ICAO hopes it will cover 84% of global aviation emissions growth.

Industry and governments have been welcoming the news, with US secretary of state John Kerry describing it as an "historic step" and the European Commission's vice-president for the Energy Union, Maros Sefcovic, calling it an "historic milestone". Many airlines were also quick to throw their support behind the deal.

Once these platitudes die down, however, the focus will shift to the aviation industry's actual implementation of the key parts of the scheme. In some respects, it is already on the back foot.

The ICAO agreement on international flights was only necessary to begin with because the aviation industry had lobbied for them to be excluded from December 2015's Paris Agreement on climate change, arguing that inclusion would have created an unworkable assortment of regulatory requirements.

That leaves the industry open to accusations that it is deciding its own standards on climate change, not helped by a last-minute removal yesterday of references to a central component of the Paris accord – "limiting global warming to well below 2°C".

Lou Leonard, the World Wildlife Fund's senior vice-president of climate and energy, was quick to pick up on that concern: "This deal was the world's first opportunity to test whether the new Paris Agreement would change the way we do business and rally the world toward its new goals.

"Yet just hours after celebrating the Paris Agreement's early entry into force, countries at ICAO are sending mixed signals about their ambition to reduce emissions by weakening the link between the aviation mechanism and the temperature goals set in Paris," Leonard states.

To mitigate concerns regarding how seriously it is taking this issue of climate change, the aviation industry can already cite the rise of fuel-efficient aircraft and efficiencies from ATC initiatives such as Single European Sky, plus investment in biofuel development.

However, an inconvenient truth when it comes to aviation emissions is that the global commercial airliner fleet will only get bigger. That creates a huge challenge.

FlightGlobal's recently released Flight Fleet Forecast predicts deliveries of new passenger and freighter aircraft totalling 42,800 in number over the next 20 years, far outpacing retirements.

As the International Energy Agency warned last year, in a 40-year outlook, the aviation industry will struggle to meet any meaningful emissions targets as long as traffic is rising and alternative fuels remain a niche concern, regardless of the efficiencies introduced by new aircraft.

This was echoed by Patrick Gruber, chief executive of biofuel specialist Gevo, who told FlightGlobal in May: "If the aviation industry really wants to reduce its greenhouse gas emissions, it must have renewable carbon as a feedstock."

Practical responses in this and other areas will take a while to emerge, but will be critical. Themes such as aircraft efficiency, ATC improvements and alternative fuels are hardly new, but will only become more important.

Airbus chief executive Fabrice Bregier was quick to highlight those areas in the airframer's initial response to the agreement: "Airbus is fully committed to all pillars of the industry's climate action plan through delivering the world's most fuel efficient aircraft, supporting air traffic management and airport operations improvements around the world and facilitating the wider adoption of sustainable alternative fuels," he says.

And speaking yesterday, IATA chief Alexandre de Juniac hailed the news while also acknowledging that hard work was to come. "There is still a lot of technical work to ensure effective and efficient implementation, and to ensure the environmental integrity and administrative simplicity of the scheme," he states. "In the coming years, we will be working closely with ICAO on capacity-building both for regulators and the industry."

Having said the right things and tied itself to this agreement, the aviation industry now faces the tough challenge of making it happen while retaining broad commitment to its aims. Achieving a balance between allowing traffic growth and taking meaningful action on emissions is not going to be easy.

Source: Cirium Dashboard