Reducing emissions from air transport

Progress so far

It may be thought that there has been slow progress in designing and implementing policies to reduce greenhouse gas emissions in air transport. This is perhaps a pessimistic viewpoint. Comparing the present to the situation say, ten years ago, there has been progress. Ten years ago, a number of policy options had been suggested though not implemented. In the period since, there has been a significant process of actually experimenting with policies, and setting up of medium-term arrangements. Some of these have been major initiatives, such as the setting up and operation of the EU ETS. Most of the main policy options have been tried, and there are results in terms of how they have been working (though for a more pessimistic view, see Gossling, 2018).

This can be outlined briefly:

Ticket taxes (such as the UK APD) have been implemented in a number of countries. Several of these have not been primarily directed towardsreducing emissions, though this is one of the effects at least in the geographical market where the tax is applied, subject to any shifting of flights or aircraft to other world regions. The impacts of these taxes have been studied (PwC, 2013; Forsyth et al., 2014), though many studies are not rigorous. There is a good knowledge basis on them. Their economic effects have been analysed to some degree. At the time of writing, there is renewed interest in ticket taxes as a way of reducing emissions.

• • There has been rather less analysis of fuel taxes. There are a number of countries which are levying them in domestic air transport, though not in international air transport. This reflects the widespread belief that international treaties and agreements prohibit their use, though this belief is being challenged (see Hemmings et al. in this volume). There may be more scope for countries or groups of countries to implement fuel taxes than has been thought.
• • Perhaps the most important emissions reduction policy to be applied to air transport has been the EU ETS. Air transport was included in the broader ETS in 2012, and it has continued to operate. This ETS allows (to an extent) trading between industries. There is ongoing research on its extension to non-CO, emissions.
• • ICAO has been making progress towards setting carbon standards for engines.
• • There is widespread, ongoing research into bio and other low carbon fuels, such as power-to-liquid-based kerosene (PtL). So far, a large number of airlines have been conducting experiments with biofuels. However, such fuels are all still in the experimental stage, and these have not yet been used extensively.
• • At the time of writing (2019), ICAO is on track to implement the COR-SIA mechanism to cap carbon emissions from international air transport at 2020 levels (see Maertens, Grimme and Scheelhaase, and Haag, in this volume). This mechanism will be voluntary initially, and it will cover an increasing number of countries. If it works as planned, it will be a significant step in freezing air transport net emissions growth from 2020, though it will not freeze total emissions.
• • Over the past ten years, many airlines have introduced voluntary offset schemes for passengers (see Knorr and Eisenkopf in this volume). Some of these schemes have not had much of an impact, though some airlines, such as Qantas, have claimed that passengers have been offsetting around 5%—10% of their flights (Hatch, 2019). Increasingly, however, firms and other institutions seem to make use of such schemes for employee travel.
• • Restrictions on the development of airports has been suggested as an emissions reduction measure. For example, the UK Committee on Climate Change has argued that air transport will need to reduce its emissions and that additional capacity at airports should be capped. However, other airports and hubs, in the same or in other world regions, might at least partly take over unaccommodated traffic, thereby nullifying the effect on reducing emissions,
• • Many airports are now claiming to be carbon neutral. This may not make a large difference to overall emissions from air transport, though it is a step in the right direction.
• • Reforms to air traffic management may reduce emissions in several ways, such as by facilitating more direct flights. The yet-to-be-achieved Single European Sky holds out the promise of significant carbon reductions (at least per flight, seat or passenger) if actually implemented, but may also enable additional growth.
• • Changes in operating procedures of airlines can reduce emissions. Airlines are exploring these and will respond to incentives such as those from fuel taxes.

In short, there is currently quite a lot going on, though several policies (voluntary offsets) are more symbolic than real. It is rather piecemeal, and there is little integration of policies. Some policies can be inconsistent with one another. A lot is experimental and limited. As far as one can tell, little has been done by way of evaluation of effectiveness, in terms of actually reducing emissions. Some have suggested that little by way of emissions reduction has been achieved. This may or may not be so, though it is likely that governments have not tried to make large differences intentionally - they are proceeding cautiously. If need be, they can ramp up their effects with the suite of policies measures at their disposal.