The ultimate objective of the United Nations Framework Convention on Climate Change (UNFCCC) is to achieve stabilization of greenhouses gas concentrations in atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system.
The Kyoto Protocol which was adopted by the Conference of the Parties to the UNFCCC in December 1997 entered into force in 16 February 2005, calls for developed countries (Annex I parties) to pursue limitation or reduction of greenhouses gases from "aviation bunker fuels" working through ICAO (Article 2.2 of the Protocol).
The Kyoto Protocol treats international and domestic emissions from the aviation sector differently in that developed countries are called on to pursue the limitation or reduction of greenhouses gases from international aviation working through ICAO (Article 2.2 of the Protocol), while domestic aviation emissions are included in their national targets, the potential advantages of harmonizing treatments of the two categories of emissions have been noted and it has been acknowledged that some Contracting States or groups of States are already taking action to design options for reducing emissions from domestic sectors including domestic aviation emissions.
Aviation was the first sector to request the Intergovernmental Panel on Climate Change (IPCC) to prepare a full assessment of the impact of its activities. A comprehensive assessment of aviation's impact on the atmosphere is contained in the Special Report on Aviation and the Global Atmosphere, which was prepared at ICAO's request by the IPCC, in collaboration with the Scientific Assessment Panel to the Montreal Protocol on Substances that Deplete the Ozone Layer and was published in 1999.
The IPCC special report recognized that the effects of some types of aircraft emissions are well understood, it revealed that the effects of others are not, and identified a number of key areas of scientific uncertainty that limit the ability to project aviation impacts on climate and ozone. Since publication of the IPCC special report, further work has been undertaken on some of these key areas of scientific uncertainty, such as the influence on contrails and aerosols on cirrus clouds and the climate impact from oxides of nitrogen and methane. Therefore, ICAO requested that the IPCC include an update of the main findings of the special report in its Fourth Assessment Report (IPCC AR4) published in 2007.
The new findings related to aviation emissions in IPCC AR4 are inter alia:
- Due to developing scientific knowledge and more recent data estimates of the climate effects of contrails have been lowered and aircraft in 2005 are now estimated to contribute about 3.0% of the total of the anthropogenic radiative forcing by all human activities;
- Total CO2 aviation emissions is approximately 2% of the Global Greenhouse Emissions;
- The amount of CO2 emissions from aviation is expected to grow around 3-4 per cent per year; and
- Medium-term mitigation for CO2 emissions from the aviation sector can potentially come from improved fuel efficiency. However, such improvements are expected to only partially offset the growth of CO2 aviation emissions.
The IPCC initiated the preparation of the Fifth Assessment Report (AR5), which is scheduled to be completed in 2014. ICAO participated in the IPCC process to ensure that issues related to scientific understanding of aviation’s impacts on global climate are covered in the AR5.
Programme of Action on International Aviation and Climate Change
The 36th Assembly in September 2007 recognized, inter alia, “the critical importance of providing continuous leadership to international civil aviation in limiting or reducing its emissions that contribute to global climate change”. The Assembly requested that the ICAO Council “facilitate action by States by vigorously developing policy options to limit or reduce the environmental impact of aircraft engine emissions, developing concrete proposals and providing advice as soon as possible to the Conference of the Parties of the UNFCCC, encompassing technical solutions and market-based measures, while taking into account potential implications of such measures for developing as well as developed countries”.
In order to achieve this, the Assembly requested the Council to:
- form a new Group on International Aviation and Climate Change (GIACC) composed of senior government officials representative of all ICAO regions, with the equitable participation of developing and developed countries, with technical support provided by the Committee on Aviation Environmental Protection (CAEP), for the purpose of developing and recommending to the Council an aggressive Programme of Action on International Aviation and Climate Change, based on consensus, and reflecting the shared vision and string will of all Contracting Sates”; and
- “convene at an appropriate time, taking into account the fact that the fifteenth meeting of the Conference of the Parties (COP15) of the UNFCCC will be held in December 2009, a high-level meeting (HLM-ENV/09) to review the Programme of Action recommended by the Group”.
Accordingly, the Council established the GIACC composed of 15 senior government officials reflecting equitable participation from developed and developing States. The Group held its fourth and final meeting in May 2009 during which it developed a Programme of Action on International Aviation and Climate Change and submitted it to the Council for its consideration. The Council fully accepted the Programme of Action in June 2009 as a positive development to limit or reduce aviation’s climate impact. All documents related to the GIACC are available at Legacy.icao.int/icao/en/atb/meetings/GIACC/Giacc_Root.html.
High-level Meeting on International Aviation and Climate Change
The High-level Meeting on International Aviation and Climate Change (HLM-ENV/09) was convened in October 2009 to review the Programme of Action that was developed by the GIACC and accepted by the Council. The Meeting welcomed the decision of the Council to fully accept the GIACC’s Programme of Action, reaffirmed ICAO’s leading role in matters involving international aviation, and approved a Declaration as well as Recommendations regarding further work for the Council on international aviation and climate change. In November 2009, the Council fully accepted the outcome of the HLM-ENV/09. All documents related to the HLM-ENV are available at Legacy.icao.int/Highlevel2009/.
In summary, the HLM-ENV/09 agreed on:
- a global goal of 2 per cent annual improvement in fuel efficiency until the year 2050, and further exploration of the feasibility of more ambitious medium and long-term goals, including carbon-neutral growth and emissions reductions;
- development of a global CO2 Standard for aircraft and facilitation of further operational changes to reduce aviation emissions;
- development of a framework for market-based measures in international aviation;
- further elaboration on measures to assist developing States and to facilitate access to financial resources, technology transfer and capacity building; and
- submission of States’ action plans, outlining their policies and actions, and annual reporting of data to ICAO on their aviation fuel consumption.
The Declaration and Recommendations by the HLM-ENV/09 strike a balance between the views of all member States and represent their collective will and determination to act in a coherent and cooperative manner to address international aviation and climate change. It is the first and only globally-harmonized agreement from a sector on a goal to address its CO2 emissions.
In parallel with the development of the Programme of Action, CAEP continued to make progress on the present and future environmental trends assessment (see Modelling and Databases) of aircraft engine emissions. The assessment results, together with other information related to technological, operational and market-based measures developed by CAEP, were provided to the GIACC and the HLM-ENV/09 for their deliberations. In line with the recommendation by the GIACC and the HLM-ENV/09, the eighth meeting of CAEP in February 2010 agreed on a plan for the development of an aviation CO2 emissions Standard, aimed at having a Standard for consideration at CAEP/9 in 2013.
Alternative Fuels for Aviation
The 36th Session of the ICAO Assembly in September 2007 also “recognized the importance of research and development in fuel efficiency and alternative fuels for aviation that will enable international air transport operations with a lower environmental impact”, and encouraged the Council to “promote improved understanding of the potential use, and the related emissions impacts, of alternative aviation fuels”.
In response to the mandate above, ICAO organized a Workshop on Aviation and Alternative Fuels (WAAF/09) in February 2009 to explore potential options, challenges to development and deployment as well as initiatives to promote international cooperation in sustainable alternative fuels for aviation. The workshop served as a preparatory event for the Conference on Aviation and Alternative Fuels (CAAF/09) in November 2009.
The CAAF/09 endorsed the use of sustainable alternative fuels for aviation, particularly the use of drop-in fuels in the short to medium-term, as an important means of reducing aviation emissions. The Declaration and Recommendations approved by CAAF/09 (see“Alternative Fuels”) affirmed the commitment of States and industry to develop, deploy and use sustainable alternative fuels to reduce aviation’s emissions. To facilitate, on a global basis, the promotion and harmonization of initiatives that encourage and support the development of sustainable alternative fuels for aviation, the CAAF/09 established an ICAO Global Framework for Aviation Alternative Fuels. The Global Framework is a web-based living document and updated whenever new information is provided by member States and international organizations.
The outcome of the HLM-ENV/09, together with that of the CAAF/09, was provided to COP15 in December 2009 (see ICAO’s Statements/Submissions). However, due to the complex negotiating process that took place in COP15, this substantial agreement was not considered as a basis for negotiations on international bunker fuels and no specific decision was taken on how to address GHG emissions from international aviation.
In light of this outcome, ICAO has strived to make further progress on the recommendations of the HLM-ENV/09 and CAAF/09, toward the development of proposals for more ambitious policies on international aviation and climate change, to be considered by the 37th Session of the ICAO Assembly in September 2010.
To facilitate the progress, ICAO has established a process and initiated the preparation of the Assembly Resolution on international aviation and climate change for presentation to the Assembly. Three main areas where further progress could be achieved are:
- exploring the feasibility of more ambitious goals including carbon-neutral growth of the sector and long-term emissions reductions, moving beyond the global commitment of a 2 per cent annual fuel efficiency improvement up to 2050;
- developing a framework for market-based measures in international aviation; and
- elaborating on measures to assist developing States and to facilitate access to financial resources, technology transfer and capacity building.
Policies on international aviation and climate change adopted by the 37th Session of the ICAO Assembly (see “Assembly – 37th Session”) will be subsequently presented to COP16 in Mexico.