According to data revealed by the International Energy Agency (IEA), combined aviation and marine transport produce 3% of all anthropogenic GHG emissions worldwide. More than two-thirds of said emissions are generated by international transport, with marine transport accounting for the largest part.
However, the magnitude of the emissions generated by marine transportation is highly uncertain and potentially much greater than IEA estimates. Marine fuel sales data reported to IEA and used in top-down emission estimates are widely believed to be unreliable. This is mostly due to inconsistent reporting methods used in countries outside the Organization for Economic Cooperation and Development (OECD).
A wide range of forecasts and scenarios indicate that aviation and maritime transport will significantly grow over the next decades. This increase would lead to a rise in CO2 emissions, despite efforts to mitigate them through technology, operations and the use of low-carbon fuels.
Aviation activities, including flights but also airports, have a negative impact on the environment; ranging from greenhouse gas emissions, air pollution, acoustic pollution, water usage, and waste generation.
Additionally, GHG emissions in the EU from international aviation have more than doubled since 1990.
Direct emissions from aviation account for approximately 3% of the EU’s total greenhouse gas emissions. They also account for more than 2% of global emissions. Therefore, if international aviation were a country, it would among the top ten producers of global emissions.
A person that takes a flight from London to New York and vice versa generates approximately the same amount of emissions produced by an average person in the EU by heating their home for an entire year.
By 2020, emissions from international aviation activities will be approximately 70% higher than in 2005. Furthermore, the International Civil Aviation Organization (OACI) forecasts that by 2050 it could grow by an additional 300% to700%.
In response to this reality, CO2 emissions from aviation were included in the EU ETS in 2012. Under this scheme, which is the largest multilateral emissions trading regime, all airlines operating in Europe must monitor, inform, and verify their emissions; as well as purchase emissions rights per every ton of CO2 issued, which cover a certain amount of flights per year.
For a long time, navigation emissions have been categorized as “difficult to reduce”. However, technological developments made over the past years made it so that a significant reduction of emissions in the maritime sector can be a politically viable target. In this context, many countries are demanding it and are taking measures to achieve this.
Electric propulsion systems are rapidly evolving in the maritime sector. So far, these systems are being implemented in interior, coastal, and ferry transportation.
International maritime trade, on the other hand, will most likely require low-emissions liquid fuels, which are far from being marketed. Several countries in Europe and Asia and even the United States have launched pilot projects that use renewably generated hydrogen and ammonia. The main goal is to use fuels that do not release CO2 when burned since they do not contain carbon.
The responsibility of reducing emissions in the maritime sector was delegated to a specialized UN agency: the International Maritime Organization (IMO).
While the IMO has progressed slowly, in recent years many countries have publicly supported the zero-emissions target.
In the framework of the IMO negotiations of April 2018 in London, EU members agreed on a common stance to support the plan of reducing GHG emissions by 70%-100% for maritime global merchandize transportation by 2050, as compared with 2008 levels.
Ultimately, the agreement that resulted from the IMO establishes a reduction of “at least” 50% by 2050. Meanwhile, efforts to completely eliminate CO2 emissions will continue in line with the Paris Agreement.
The political initiative to set the aforementioned goal at zero net emissions for international maritime transport remains strong and is encouraged by the insular nations of the Pacific and EU countries.
The road ahead
Aviation and marine transport have historically been kept outside the UN climate convention. This is mostly due to their international nature and the difficulty to assign emissions to specific countries. As a result, global progress in the fight against emissions has been slow in these sectors.
Although there is progress in the process of decarbonizing maritime transport, it seems that aviation will continue to largely depend on fossil fuels, considering the energy it takes to put these planes on the air.
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