Glasgow’s hosting of the world’s dignitaries in November at COP26 was meant to have been an important stage in the global attempts to minimise the effects of climate change. It was the fifth meeting of the Conference of the Parties following the 2015 Paris Agreement (at COP21), but delayed by a year because of the pandemic.

At this meeting each nation was meant to present the success of the measures taken in the intervening lustrum, and provide updates to their Nationally Determined Contributions (NDCs) to ensure global warming be limited to no more than 2°C (and preferably 1.5°C) above pre-industrial levels by the end of the century.

Geopolitics also intervened and not all the world’s leaders appeared. Two in particular, representing the countries that are the world’s second and third largest emitters of CO₂, were notable by their absence: Russia’s Putin, no doubt busy preparing to send threatening troops to the Ukraine border; and China’s Xi Jinping (although he did attend by video link) perhaps fearful of catching the latest Covid variant but also busy trying to secure deeper control over Hong Kong, Taiwan and islands in the South China Sea.

After two weeks of talks and negotiations, COP26 came up with a new global agreement — the Glasgow Climate Pact — to set the global agenda on climate change for the next decade. For the first time at a COP conference there was an explicit plan to reduce the use of coal (responsible for 40% of CO₂ emissions worldwide) but, after a late intervention by India and China, the wording was phrased as “phase down” rather than “phase out” the use of the fossil fuel. There was also an agreement to phase out subsidies for fossil fuel production and consumption.

It was agreed the the world’s countries would meet in a year’s time to agree to pledge further cuts in CO₂ emissions. Current pledges, if met, would limit global warming to only 2.4°C by the end of the century — as the chart shows, the world’s average temperatures are probably already more than 1.2°C above the average for the second half of the 19th century. The pact reiterated the findings of an IPCC report that limiting warming to no more that 1.5°C requires “rapid, deep and sustained” emissions cuts, with CO₂ emissions falling to 45% below 2010 levels by 2030 and to net-zero around mid-century.

The 40 or so countries who failed to update their NDCs were “urged” to do so (moderately strong wording in UN-speak) “as soon as possible”. The pact also “urges” countries that have not submitted long-term strategies to the UN to do so before COP27 (Egypt, 2022) “towards just transitions to net-zero emissions by or around mid-century”.

The outcome of COP26 did not please everyone, with complaints that the measures agreed do not go far or fast enough to prevent catastrophe.

Transport Day

One of the days during the conference was devoted to transport.

30 countries agreed to work together to make zero emission road vehicles the new normal by making them accessible, affordable, and sustainable in all regions by 2030 or sooner.

19 governments stated their intent to support the creation of green shipping corridors — zero-emission shipping routes between two ports. Twenty-eight offshore wind industry stakeholders committed to work together toward making zero emission operations and maintenance vessels a reality in the North Sea by 2025.

There was also an inaugural meeting of a new group — the International Aviation Climate Ambition Coalition. A declaration, signed by 18 states (representing more than 40% of global aviation emissions), committed to work together to achieve “a new aviation decarbonisation target” through ICAO and support the fair “implementation of and strengthen the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA)”. They agreed to promote the development and deployment of “sustainable aviation fuels that reduce lifecycle emissions and contribute to the achievement of the UN Sustainable Development Goals (SDGs), in particular avoiding competition with food production for land use and water supply”; and of “innovative new low- and zero-carbon aircraft technologies that can reduce aviation CO₂ emissions”.

The Aviation declaration doesn’t change much — it effectively confirms that ICAO is the forum for ensuring the industry targets net-zero emissions by 2050. The signatories are principally countries in North America, Europe and North East Asia (but also include the Maldives, one those most at risk from rising sea levels).

Notably absent are any of the countries which might be expected to provide the substantial portion of aviation growth over the next couple of decades; in particular India, and China.

IATA: Fly Net Zero

Pre-empting the political negotiations in Glasgow, IATA at its AGM in October approved a resolution for the global air transport industry to achieve net-zero carbon emissions by 2050, aligning with the Paris Agreement goal for global warming not to exceed 1.5°C.

It seems only appropriate that it should have been Willie Walsh as the organisation’s director general to make the announcement: it was he as CEO in 2019 who committed IAG to a target of net-zero emissions by 2050 — the first airline to do so (see Aviation Strategy, Nov 2019).

The proposal is a major challenge. Despite the setback from the pandemic, underlying fundamentals suggest that the airline industry will still be a long term growth industry. Total airline passenger numbers worldwide are expected to exceed the 4.4bn achieved in 2019 by 2025 and IATA seems to be forecasting a modest annual average rate of growth of 3% a year over the following 25 years. By 2050 total passenger numbers carried could exceed 10bn.

Without taking additional efforts, total CO₂ emissions from the industry (in prepandemic times accounting for 2-2.5% of the world’s total) would also double by the middle of the century to nearly 2 gigatonnes (Gt). The Air Transport Action Group (ATAG) — a grouping of companies and associations throughout the value chain of the commercial aviation sector designed to work together on long-term sustainability issues — somewhat speciously points out in its recent Waypoint 2050 report that technological developments and operational changes since the 1990s had already removed an estimated total 11Gt of emissions; and had the industry frozen efficiencies at 1990 levels, it would have been looking forward to having to abate over 5Gt of CO₂ a year by 2050 (see chart).

Sustainable Aviation Fuel

By far the largest element of IATA’s path to net-zero comes from the use of Sustainable Aviation Fuels (SAF) — which it estimates will need to account for 65% of the total industry fuel requirement and 65% of the expected 1.8Gt CO₂ emissions in 2050 (see chart). This will require significant governmental and political support to provide the incentives for a significant the ramp up of production (from the current 100m litres a year to 450bn litres in 2050) and bring the cost (currently a multiple of the price of Jet Kerosene) down to competitive levels. Echoed by the IACAC declaration at Glasgow, IATA emphasises that the industry is committed to only using sources for SAF that do not diminish biodiversity or compete with food and water.

The group notes the distinct difference in approach to such support on either side of the Atlantic.

In the USA, the California Low Carbon Fuel Standard, designed to reduce greenhouse gas emissions in the transportation sector, was updated in 2019 to allow SAF to be treated as eligible credits and acts as an incentive for SAF production as those credits can be sold on to other participants in the CA-LCFS. The US Renewable Fuel Standard (RFS), dating back to 2005, focused on renewable fuel for ground transportation, requiring a minimum amount of renewable fuel on an annual basis, growing over time. It offers SAF an “opt-in” approach allowing SAF to generate compliance units without aviation fuel generating compliance obligations. This approach increases SAF’s competitiveness with renewable diesel, while refraining from imposing a mandated SAF use obligation.

And then in May 2021 the US Congress introduced the Sustainable Skies Act, aiming to boost incentives to use SAF. It provides credits starting at $1.50/gallon for blenders that supply SAF with demonstrable lifecycle GHG savings of at least 50% and rewards higher GHG achievement up to a maximum of $2/gallon. The legislation requires eligible SAF to use the full set of ICAO sustainability criteria as one of the safeguarding provisions to ensure its environmental integrity. A complementary proposal also includes a $1bn grant over five years to expand the number of SAF production facilities in the US.

In September 2021, the US announced a new sustainable aviation fuel goal to increase the production of SAF to at least 3 billion gallons per year by 2030. New actions include:

• A proposed SAF tax credit that aims to cut cost and rapidly scale up domestic production of SAF.
• Continuous funding opportunities to support SAF projects and fuel producers, with the launch of a new SAF Grand Challenge to ramp up domestic production of SAF.
• Closely working with international partners to support the global scale up and availability of SAF.

In contrast Europe has taken the approach of applying sticks rather than giving carrots. In July 2021, the European Commission published a package of legislative proposals branded “Fit for 55”. One component of the package is the ReFuelEU proposal which aims to boost production and uptake of SAF.

The proposal includes a blending mandate imposed on aviation fuel suppliers, with the obligation for the suppliers to ensure that all aviation fuel supplied to aircraft operators at EU airports contains a minimum share of SAF, including a minimum share of synthetic fuel.

The mandate is expected to start in 2025 with a minimum volume of SAF at 2%, increasing in five-year intervals to ultimately reach a minimum volume of 63% in 2050, of which 28% would consist of synthetic aviation fuels.

To avoid tankering, all airlines departing from EU airports will be obliged to uplift jet fuel prior to departure. The amount of jet fuel uplifted must correspond to the volume of jet fuel necessary to operate the planned flight, regardless of the destination. The yearly quantity of aviation fuel uplifted by a given aircraft operator at a given EU airport has to be at least 90% of the annual aviation fuel required. The legislative proposal also requires aircraft operators' reporting to EASA.

Another proposal in the “Fit for 55” package is to remove the tax exemption on jet fuels. The tax would be introduced gradually from 2023 before being enacted in full in 2033 at a rate of €10.75/GJ (which translates to $535/tonne compared with a current price of $722/t). SAF would benefit from a minimum rate of zero. However this tax would only apply to intra-EU flights which are said to account for only 40% of EU aviation emissions.

The proposal is subject to the normal legislative procedure and requires scrutiny (amendment) and approval by the EU Council and Parliament, which could take up to two years.

IATA is clearly not in favour of the EU proposal, pointing out that mandated solutions that are not accompanied by positive measures (such as the use of public money to help reduce the price gap between SAF and conventional jet fuel) can result in higher prices and a deadweight loss on consumers.

Carbon offset capture and storage

The second largest contributor to the path to net-zero comes from carbon offset, capture and storage — providing 19% of planned emissions reductions. This will be particularly important during the next two decades with the mechanism of ICAO’s CORSIA scheme designed to allow carbon neutral growth to the mid 2030s. IATA points out that the net-zero commitment is based on removing as much as possible CO₂ in-sector or at source, but it is possible that by 2050 some emissions may still need to be offset or removed from the atmosphere by other means. But it expects reliance on carbon offsets to fall rapidly as SAF comes on stream in large quantities.

The emergence of carbon, capture, utilisation and storage (CCUS) processes is seen as a vital tool in the aims to meet the goals in the Paris Agreement. If these processes also involve using the carbon captured to generate SAF, IATA suggests it could even be a carbon-negative option.

Technology

The next major section for emissions reductions comes from new technology — estimated to provide 13% of the total. Battery powered electric aircraft may be a possibility by as early as 2025; but they will of necessity be small (up to 20 seats) and with a maximum flight time of up to an hour, and provide a replacement for a tiny proportion of the industry.

Battery technology will no doubt continue to improve but it will probably be many years before batteries approach anywhere near the energy density of jet kerosene to power larger, narrowbody equipment — the workhorse of the industry. Long haul widebody aircraft would require a currently unimaginable radical redesign.

IATA suggests that by 2030, electric or hydrogen hybrid equipment could be available with capacity of 50-100 seats and flight times of up to 90 minutes; and hydrogen powered regional aircraft by the end of the 2030s seating up to 150 passengers. It is interesting to note that Norway has set a goal of making all short-haul flights lasting up to 1.5 hours all-electric by 2040.

Larger aircraft will probably have to rely on incremental improvements in existing technology to be even more fuel efficient than the current stock on offer. Geared turbofans and other advances in design may drive an additional 15-25% improvement in fuel efficiency over the next two decades.

Operations and infrastructure

Only expected to contribute 3% to the target for reduced emissions, operations and infrastructure improvements above the normal annual 1.5%-2% efficiency gains will be a reasonably important contributor. Included in this section are such things as retrofitting aircraft for better aerodynamics (such as winglets), even lighter-weight seats, further reduction of cabin weight, and maximising engine operational efficiencies.

Air traffic management is expected to be a crucial contributor. In the US the NextGen ATC will provide significant savings. Eurocontrol has been encouraging the deployment of continuous rate of climb/descent operations to optimise flight paths. Airbus has been trialling what it calls “fello' fly”: flying aircraft in formation mimicking migrating geese to achieve wake energy retrieval. It suggests a potential 5-10% fuel saving on long haul flights. Who knows, the climate emergency may even be able to make the Single European Sky, first mooted over 20 years ago, a reality.

Criticism

The adoption of the Fly Net-Zero plan, as the UK daily newspaper the Guardian put it, “met less acclaim than airlines hoped”. As far as Willie Walsh and IATA are concerned it was a momentous decision, but for some environmental campaigners “essentially meaningless”.

One of the problems is that the plan focuses on the use of SAF and carbon offset, both contentious issues. For the first there is a need to educate the great unwashed that burning fuel and releasing CO₂ into the atmosphere is still acceptable when half that fuel is from truly sustainable sources.

The second requires a belief that carbon offset programmes are sufficiently monitored to be effective. Scott Kirby, CEO of United, recently described the concept as a ”fig leaf for a CEO to check a box and pretend that they’ve done the right thing for sustainability”.

For the environmental groups, however, there is no explicit element in the plan to limit demand. With the intensification of the debate following the flygskam movement, there have been growing calls to tax aviation, aviation fuel, and impose higher taxes on frequent fliers, all with the purpose of making air travel more expensive and to curb its growth. This is an almost exclusively European perspective.

However, there must be an implicit impact within IATA’s long range forecasts: airline costs will rise, as will fares. IATA estimates the total cost to airlines of mitigating the 21.2Gt of CO₂ over the next 30 years at $1.55trn.

But Greenpeace, for one, slammed the IACAC declaration at COP26 and its support for the Fly Net-Zero programme as “greenwashing" and “full of scams like offsetting, and excessive optimism on so-called ‘sustainable aviation fuels’”, insisting that policymakers “should ban short-haul flights”.

Some have indeed been doing just that. One condition of Air France-KLM’s government bailout in 2020 was to stop domestic flights where there was a train alternative of less than two and a half hours: and it was passed into law (except for connecting flights) in April 2021. Air France probably doesn’t mind: its regional operations had been heavily loss-making even in good times, and if it were legally forced to close them at least no competitor would be able to enter.

Short- vs Long-haul pollution

Such moves create positive political messages (“Look! We’re doing something for the environment”) but have a tiny impact on aviation emissions.

As the pie charts show (from Eurocontrol’s data), flights of less than 500km account for a quarter of departures but only 4% of emissions. In contrast flights over 4,000km (Eurocontrol’s definition of long haul) account for 6% of departures but nearly half of total CO₂ emitted.

It is fair to say that short haul flights have a higher level of carbon intensity (in terms of grammes of CO₂ per RPK). As the graph shows (using data from the International Council on Clean Transportation) short haul flights of less than 500km emit nearly twice as much per passenger kilometre as flights of 3,000km. On long haul flights there appears a gradual upward slope in carbon intensity. This is understandable: the longer the flight, the more fuel is needed to carry the weight of the fuel required to reach the destination.

A further example of political posturing was the New Year address from Denmark’s Prime Minister Mette Frederiksen declaring a goal to make Denmark’s domestic flights fossil fuel free by 2030. An admirable goal.

But Denmark has a very small domestic market of nine viable routes over very short distances (100-380km) and operated by small regional aircraft (an average of 67 seats, excluding the largest routes such as Aarhus-Copenhagen which supports narrowbody operations). In total, pre-pandemic, they accounted for 5% of seats into, out of, and within Denmark. At least she doesn’t want to ban essential connections, saying: “To travel is to live and therefore we fly”.

IATA recognises that its plan to reach net zero cannot be achieved by airlines alone. It will need the help and support of manufacturers, air traffic controllers, the oil industry, corporates, researchers, investors, passengers; and, above all, Governments.