International aviation & climate change: the UK's net-zero emissions proposition

In its report, the CCC, an independent advisory body on building a low-carbon economy and preparing for climate change, recommends a new emissions target for the UK of net-zero greenhouse gases by 2050. This target is designed to achieve the UK's commitment to keep the increase in global average temperature to below 2°C above pre-industrial levels under the 2016 Paris Agreement.

In 2003, the UK announced a target to reduce emissions by 60% from 1990 levels, which was increased to an 80% reduction in 2008 acknowledging a cost of between 1-2% of GDP to achieve this. The net-zero target recommended in the CCC's report does not increase this estimated cost yet proposes a significantly more ambitious approach to reductions. Of particular importance to the aviation sector, whereas initiatives under previous targets excluded international aviation and shipping, the net-zero target is proposed as a comprehensive approach inclusive of these sectors.

Despite past approaches largely ignoring international aviation for the purpose of national targets, the UK has played a positive role in climate negotiations in the UN, the EU and ICAO in relation to this sector. International initiatives such as ICAO's Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) whose offsetting mechanism comes into effect in 2021 (though it remains voluntary until 2026) will have a large role to play in managing emissions in this sector on a global scale. However, the proposed net-zero target goes beyond emissions targets set by ICAO suggesting that additional ambition and stronger regulation will be required to achieve this. The existing Climate Change Bill currently excludes international aviation and shipping thus significant amendments to existing government policy as well as the introduction of new regulation may be needed.

When considering the distribution of costs attributed to achieving a net-zero target, the report acknowledges that sectors such as aviation, which are unlikely to reduce their emissions to zero, may face resultant costs of removing emissions from the atmosphere. This may result in increasing flight costs for passengers as airlines are faced with an additional cost of doing business. It remains to be seen if and how government policy may protect the consumer from such increased costs, and the extent to which removals will be required of the aviation industry to offset its emissions.

Moreover, with the expansion of several UK airports approved, in particular the expansion of Heathrow, researchers have cited an increased capacity of 59 per cent by 2050. This is more than double the increase accounted for the in CCC’s report and could hinder the success of the 2050 net-zero proposition. Heathrow’s third runway promises to increase the number of flights from 480,000 per year to 756,000, but also claims that after 2022 there will be no increase in carbon emissions. Much of this may depend on the successes of the sector in reducing emissions through technologies such as bio fuels, electrification of aircraft and engineering for improved fuel efficiency. There are currently no commercially viable low-carbon aircraft and all flights remain reliant on fossil fuels.

Evidence points to international aviation emitting more greenhouse gases than almost any other sector in 2050 (though agriculture/land use change could rival this), and although international aviation is now included in the CCC's proposed net-zero emissions target, it is not yet considered in its carbon budgets. In the UK, aviation currently accounts for 7 per cent of total emissions but, as other sectors decarbonise and flying becomes cheaper than alternative transportation, along with proposed UK airport expansions, its share is likely to increase. Nonetheless, with a new Prime Minister set to enter Downing Street by the end of July, it remains to be seen whether a third runway at Heathrow will proceed as planned.