- In 2012, carbon dioxide emissions from international aviation and maritime transport together contributed for 1.3% and 2.2%, respectively, to global carbon dioxide emissions. Carbon dioxide emissions of international aviation and maritime transport are continuously increasing due to strong growth in transport demand. 62% and 79% of carbon dioxide emissions from international aviation and maritime transport were counted towards international emissions, not by specific country. The International Civil Aviation Organization (ICAO) adopted a goal to stabilize the carbon dioxide emissions after 2020, and the excess carbon dioxide after 2020 should be offset to achieve Carbon Neutral Growth from 2020 (CNG 2020). However, there are no precise plans for emission reduction.
According to the Kyoto Protocol, the Parties included in Annex I shall overtake limitation or reduction of aviation and maritime bunker fuel emissions in collaboration with the International Civil Aviation Organization (ICAO) and the International Maritime Organization (IMO). In relation to the IPCC Guidelines for the greenhouse gas (GHG) inventories preparation and UNFCCC reporting guidelines on annual inventories, Parties should calculated international bunker fuel emissions as part of the national GHG emissions, but should be reported separately and excluded from national total emissions since these emissions are not defined in commitments of Annex I Parties under the Kyoto Protocol.
International aviation emissions control can be considered in 2 sides, which are demand and service providers. Around 80% of total aviation emissions are from flights over 1,500 km, for which ground transport is not feasible alternative. Several solutions have been proposed for GHG emissions reduction. Video-conferencing can also be a solution for the demand side, which helps to reduce travel needs, save time and money for businesses and individuals. For the service provider side, feasible solutions can be improving fuel efficiency, shifting to cleaner fuels and so on. For example, Japan, Brazil, India and the US have introduced jet fuel taxes for domestic flight, and Norway has implemented a carbon tax on domestic aviation since 1991.
International maritime transport emissions All GHG emissions from shipping are from the fuels used in ship engines. 85% of fuel used is Heavy Fuel Oil (HFO), and the remainder is Marine Diesel Oil (MDO) with minimal usage of Liquefied Natural Gas (LNG). After restrictions on sulfur emissions were enforced in Emission Control Areas (ECAs) in North America and northern Europe, most ships switch to low-sulfur fuel, which are Marine Gas Oil (MGO) and LNG, when travelling through an ECA. They can use scrubber with HFO to capture sulfur emissions. However, these solutions do not have much effect on GHG emissions reduction, except using LNG.
- European Parliament (2015) Emissions Reduction Targets for International Aviation and Shipping. Retrieved from http://www.europarl.europa.eu/RegData/etudes/STUD/2015/569964/IPOL_STU(2015)569964_EN.pdf
- Gençsü, I. and Hino, M., 2015. Raising Ambition to Reduce International Aviation and Maritime Emissions. Contributing paper for Seizing the Global Opportunity: Partnerships for Better Growth and a Better Climate. New Climate Economy, London and Washington, DC. Retrieved from http://2015.newclimateeconomy.report/wp-content/uploads/2015/09/NCE-Aviation-Maritime_final.pdf