A lack of emission reduction targets for aviation risks undermining global efforts on 2⁰C warming objective
Fri 20 Nov 2015 – A lack of adequate sectoral targets and appropriate action to reduce emissions from international aviation and shipping risks undermining efforts elsewhere to achieve the internationally agreed goal of keeping global warming below the 2⁰C threshold, finds a study prepared for the European Parliament. International aviation’s current 1.3% share of global CO2 emissions may rise to a substantial 22% by 2050 if the sector does not step up its ambition and continues to fall behind other sectors working to combat climate change, it warns. While full decarbonisation of aviation within the next 30 years is unrealistic, argues the study, stabilising emissions at 2020 levels, as proposed by ICAO Member States, “is clearly not enough.” It is important to establish targets for both aviation and shipping that clearly indicate emissions cannot grow unlimited and unregulated, it advises EU lawmakers.
The strong growth in air transport demand has led to an average annual growth of 2.9% in CO2 emissions, despite considerable efficiency improvements, and are expected to rise even more strongly in the future, perhaps by as much as 4.4% per year. If unchecked, international aviation and shipping together will in 2050 emit as much as the European Union today, notes the policy study, which was provided for the European Parliament’s environment committee and carried out by Germany’s Oeko-Institut.
ICAO has set an annual fuel efficiency improvement target of 2% and an aspirational goal of carbon-neutral growth from 2020, although has yet to agree on how to ensure the latter is achieved.
The study looks at a number of potential mitigation targets for consideration by policymakers, ranging from emissions stabilisation at 2020 levels – carbon-neutral growth (CNG) – to full decarbonisation of the aviation sector by 2050 using a global carbon budget approach. The first is considered inadequate as it does not lead to the absolute reductions that are required, while the second is considered probably too ambitious.
In 2020, CO2 emissions from international aviation (therefore excluding domestic aviation and roughly 62% of total global aviation emissions) are projected by ICAO to reach 752 Mt under a mid-range scenario, about 79% above the 2005 level of 419 Mt. To stay below 2⁰C, the study therefore recommends the target for aviation for 2030 should not be higher than 39% above 2005 emission levels. By 2050, those emissions should be between 41% and 96% lower than the 2005 level. The higher reduction is based on full decarbonisation, whereas the lower may just be in line with the 2⁰C trajectory. If aviation’s non-CO2 impacts were to be taken into account when consistent data becomes available, these targets would need to be even more stringent, it adds.
In addition to a short-term (up to 2020) goal of a 1.5% improvement in average annual fuel efficiency and then carbon-neutral growth from 2020, the aviation industry itself has set a target to reduce aviation net emissions by 50% by 2050 compared to 2005 levels. This, says the study, may therefore be compatible with the global long-term climate goal if non-CO2 effects are not taken into account. However, it is dependent on when CNG is turned into a declining trajectory, which the study’s authors have assumed in their analysis will start in 2030. The more the decline from CNG is postponed, the higher the aggregated emissions and the stronger the deviation from a trajectory compatible with the global long-term goal, they say.
A consideration posed by the study’s authors for policymakers when setting appropriate targets for the aviation and shipping sectors is how to compare them with other industrial sectors and efforts elsewhere. Those sectors – for example electricity generation, steel or cement production – may be equally important to the global economy but will likely be covered by the post-Paris global mitigation targets. The study argues that international aviation and shipping (domestic emissions should be included in national targets) need to be covered by similar requirements.
It points out that aviation alone would rank 21st as a country in terms of gross domestic product (GDP), about the same as Switzerland and larger than some members of the G20. In global emissions terms, aviation would rank seventh if treated as a country, again higher than many developed nations. Considering it as a separate country and resembling an industrialised rather than a developing country, the authors have also provided a potential mitigation target based on the EU’s own emissions reduction ambitions for 2050.
The study concludes that it is unlikely that targets which are compatible with the below 2⁰C objective can be achieved only with technological and operational improvements, and may require both encouraging behavioural change that leads to reduced demand for air transport and the offsetting of climate impacts by financing emission reductions in other sectors.
The draft negotiating text for the upcoming Paris COP21 climate conference that was released earlier in the year called for the need for global sectoral emission reduction targets for international aviation and shipping, but was removed in a later slimmed-down version. At the insistence of the EU and some least developed countries, text was recently reinserted that calls on Parties to pursue limitations or reductions in greenhouse gas emissions through ICAO and IMO from the two sectors but has no reference to targets (see article).
A synthesis report published by the UNFCCC on October 30 that provides estimates of the aggregate GHG emission levels in 2025 and 2030 resulting from the intended nationally determined contributions (INDCs) submitted so far by countries in advance of COP21, acknowledges emissions from international aviation and maritime transport are not included in INDCs. However, the report has assumed the ICAO post-2020 CNG target will come into effect and has based its global aggregate emissions estimates on a plateauing of international aviation emissions from 2020 of 750 Mt (page 25, paragraph 107).
