Menu Close

International Aviation and Climate Change

I. Introduction

International aviation presents a serious issue when it comes to climate change. Two percent of global carbon dioxide (CO2) emissions can be attributed to international flights, and the amount of CO2 emissions from these flights is growing rapidly.[1] From 1990-2010 CO2 emissions from the international aviation industry increased 40%; if the aviation sector is considered its own country it would be the world’s seventh largest polluter.[2] Due to limited opportunities for enhanced fuel efficiency solutions, slow innovation, and ever-increasing global demand for international flights, there is a large gap between what is necessary to avoid a 2˚C rise in global temperature and the current projections for CO2 emissions by the aviation sector in the future.[3] These issues highlight the urgent need for action to reduce pollution in international aviation.

The Paris Agreement is a landmark deal in the climate change arena, but international aviation was conspicuously absent from the text.[4] While domestic aviation is included in individual nations’ greenhouse gas inventories, emissions from international aviation present a much greater problem which must be addressed in an increasingly globalized economy.[5] The importance of an international solution is made evident by the fact that many countries—including the United States, which is the world’s largest polluter in domestic aviation—work within the framework of the International Civil Aviation Organization (ICAO) to establish international standards first, and then establish domestic standards which conform to the international ones.[6] If the world wants to remain serious about combating climate change, it must act to reign in CO2 emissions in the rapidly growing international aviation industry.

II. The ICAO Solution

In October 2016, the International Civil Aviation Organization—the UN specialized agency tasked with governance of international civil aviation—after years of negotiations, adopted a measure designed to deal with the problem of CO2 emissions in aviation. The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) is a market-based-measure intended to achieve the goal of carbon-neutral growth in the industry after 2020.[7] The scheme will be implemented in three phases: the pilot phase, first phase, and second phase. The pilot and first phases will run from 2021-2026 and will be completely voluntary.[8] The second phase will run from 2027-2035 and will be mandatory for nations with significant activity in the international aviation industry.[9] Only flights in which the nation of origin and destination are both participants will be covered.[10]

The scheme addresses emissions and offsetting by focusing on reductions outside the industry.[11] The average level of CO2 emissions measured from 2019-2020 will be used as a benchmark. The level of emissions above that benchmark in each subsequent year will be the amount required to be offset in any given year. The amount required to be offset will be distributed among the airlines of participating countries.[12] Offsetting will be accomplished through the use of emissions units (1 unit equals 1 tonne of CO2) including “offset credits” and “allowances.”[13] Acquiring and redeeming offset credits is accomplished primarily by funding carbon-reducing projects such as forestation, while allowances can be purchased through established carbon markets.[14]

III. Praise and Criticism of the ICAO Solution

The ICAO has been met with praise from leaders in government and industry. ICAO President Olumuyiwa Bernard Aliu called the agreement a “bold decision and an historic moment.”[15] United States Secretary of State John Kerry remarked that the ICAO scheme builds on the goals of the Paris Agreement.[16] Industry representatives have lent their support, including Michael Gill of the Air Transport Action Group who stated that that the support of all the states in the agreement show a real commitment to the issue of global climate change.[17] The EU Commissioner of Transportation, Violeta Bulc, called the agreement a “new chapter…where sustainability becomes part of the way we fly.”[18]

However, criticism of ICAO has been prevalent as well. According to Lou Leonard, Senior Vice President of the World Wildlife Fund, the agreement does not go far enough, and it poses the risk that international aviation will take up too much of the remaining global carbon budget and restrict the ability to reach the temperature goals set in the Paris Agreement.[19] In fact, an analysis by the International Council on Clean Transportation found that the CORSIA will only offset about three-fourths of the emissions growth above 2020 levels (the goal of ICAO is to be carbon-neutral after 2020).[20] This is due in part to the fact that emissions reductions under the scheme are accomplished outside of the industry itself through offsetting. The Center for Biological Diversity states that this process “offloads the airlines’ carbon debt onto third parties” and refers to the CORSIA as a “dangerous shell game.”[21] There are also participation issues involved in the scheme. Some countries with large contributions to international aviation—Russia, Brazil, and India—are unlikely to participate at least in the voluntary phase of the program, which lasts until 2027.[22] This problem is compounded by the fact that the program only effects flights that originate from and travel to countries which are both participants.[23]

 IV. Going Forward

While the agreement by ICAO and the scheme it develops are vital steps forward in the fight to reduce CO2 emissions in international aviation and their effect on climate change, more must be done. First, the agreement should be mandatory for all nations with large international aviation industries, and it should apply to flights that either originate from or fly to a participating country. Second, and more importantly, a more robust and effective market-based-measure must be implemented. The offsetting of the CORSIA is not sufficient to address the future emissions growth presented by the increasing demand in the international aviation sector. Other measures were discussed during the ICAO negotiations, including an emissions trading system (ETS) such as a cap-and-trade scheme, and a carbon tax.[24] A carbon tax is a simple, effective, and easily administered way to bring about a reduction in emissions, specifically by encouraging an increase in design and development of more efficient airplanes. A cap-and-trade system is better than the current offsetting scheme as it reduces emissions within the industry itself, rather than attempting to make up for pollution elsewhere. The European Union currently has an ETS for EU carriers.[25] The ICAO could use that system as a blueprint and adopt and/or modify it to apply globally with relative ease.[26] If the world wishes to hold true to the ideals espoused in the Paris Agreement, it cannot ignore the ever-increasing problem posed by international aviation. The latest ICAO agreement is a step forward, but unless we act quickly to improve the agreement, it will have been a misstep.

The views and opinions expressed in this blog are those of the authors only and do not reflect the official policy or position of the Michigan Journal of Environmental and Administrative Law or the University of Michigan.

*Eric Ashby is a Junior Editor on MJEAL. He can be reached at

[1] Center for Climate and Energy Solutions, Reducing Carbon Dioxide Emissions From Aircraft, (last visited Nov. 11, 2016).

[2] Center for Climate and Energy Solutions, supra note 1.

[3] Alice Bows-Larkin et al., Aviation and Climate Change-The Continuing Challenge, in Encyclopedia Of Aerospace Engineering, 1 (Wiley Publ’g, 2010).

[4] Flightpath 1.5˚, Frequently Asked Questions,, (last visited Nov. 11, 2016) at 3.

[5] Flightpath 1.5˚, supra note 4.

[6] Press Release, Center for Climate and Energy Solutions, Reducing Carbon Dioxide Emissions From Aircraft, (last visited Nov. 11, 2016).

[7] International Civil Aviation Organization, What is CORSIA and How Does it Work?, (last visited Nov. 11, 2016).

[8] International Civil Aviation Organization, supra note 7.

[9] International Civil Aviation Organization, supra note 7.

[10] International Civil Aviation Organization, supra note 7.

[11] International Civil Aviation Organization, supra note 7.

[12] International Civil Aviation Organization, supra note 7.

[13] International Civil Aviation Organization, supra note 7.

[14] International Civil Aviation Organization, supra note 7.

[15] Oliver Milman, First Deal to Curb Aviation Emissions Agreed in Landmark UN Accord, The Guardian, Oct. 6, 2016,

[16] Henry Fountain, Over 190 Countries Adopt Plan to Offset Air Travel Emissions, N.Y. Times, Oct. 6, 2016,

[17] Milman, supra note 15.

[18] Milman, supra note 15.

[19] Nadia Prupis, Green Groups Warn Deal to Lower Aviation Pollution is ‘Weak Shell Game’,, Oct. 6, 2016,

[20] Henry Fountain, supra note 16.

[21] David Hodgkinson & Rebecca Johnston, The New UN Deal on Aviation Emissions Leaves Much to be Desired, The Conversation, Oct. 10, 2016,

[22] Center for Biological Diversity, supra note 6.

[23] International Civil Aviation Organization, supra note 7

[24] Hodgkinson, supra note 21.

[25] Hodgkinson, supra note 21.

[26] Hodgkinson, supra note 21.

Leave a Reply

Your email address will not be published. Required fields are marked *

%d bloggers like this: