Aviation and shipping in the spotlight

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Article Published 29 Jun 2016 Last modified 11 May 2021
10 min read
Flying off for a weekend break, cotton t-shirts made in Bangladesh, roses from Kenya… These are some of the products available to us in a well-connected, globalised world. Aviation and shipping contribute to economic growth, but they also lead to impacts on human health, the climate and the environment. Faced with future projections of growth, these two sectors have started to explore ways to reduce their impact.

Aviation and international shipping have helped to dramatically reduce distances and increase our access to cheaper holidays and goods. And they have helped to create millions of jobs at home and abroad due to increased trade and tourism.

Demand for the two sectors is expected to grow globally for more leisure, convenience and access to goods in the years ahead. Between 1995 and 2050, passenger transport in the EU, including aviation, is expected to grow by around 70 % and freight transport by 100 %. According to the International Transport Forum (ITF) at the Organisation for Economic Cooperation and Development, world freight volumes will also increase. This is partly due to projected growth in global trade. The ITF also foresees geographical shifts in trade patterns around the world, where growth in trade in emerging economies will lead to longer haulage distances.

While such growth is good for the economy, the upward trend in passenger flights and shipping poses an increased threat to the climate, the environment and human health. The aviation and maritime transport sectors are expected to see a rise in emissions of greenhouse gases (GHG) and air pollutants such as carbon dioxide (CO2), nitrogen oxides (NOx) and sulphur oxides (SOx), as well as noise pollution. Carbon dioxide emissions from the sectors currently represent 5 % of global emissions and, according to a European Parliament study, aviation and maritime transport will be responsible for up to 22 % and 17 %, respectively, of global CO2 emissions in 2050.

Up in the air

Flying is seen as a safe and convenient mode of transport. The number of flights in Europe in 2014 was about 80 % higher than in 1990. And after a drop due to the economic recession from 2008 onwards, the numbers are picking up again.

Increased numbers are partly due to a general trend towards longer flights and aircraft with more seats. Most of the growth is due to increased business by low-cost flights, which have lured passengers away from traditional carriers and opened new routes contributing to growth in the sector. This trend is expected to continue as low-cost carriers expand their fleets and start offering trans-continental flights, giving travellers more choice and more destinations. The International Civil Aviation Organisation (ICAO), the UN agency which regulates the sector, projects that the world’s commercial aircraft fleet will jump to around 47 500 by 2036, from around 26 000 in 2016.

According to 2014 preliminary data compiled by the European Environment Agency shows that GHG emissions from international aviation increased by 22.7 % between 2000 and 2007, and then fell by 3.5 % between 2007 and 2014. Excepting the recent decline, emissions have been increasing steadily. They doubled since 1990 and were 18.3 % higher in 2014 than in 2000. And the upward trend is expected to continue.

The ecological footprint of a single person taking a long-haul flight causes as much pollution as a motorist does in two months according to one study. In other words, a one-way transatlantic flight from Paris to New York in economy class generates around 381.58 kilograms of CO2, according to the ICAO’s emissions calculator. This is equivalent to emissions generated by the energy use of an average house for 10 days.

The extra noise created with increased numbers of take-offs and landings at airports also has a negative effect on health, creating more than just annoyance and sleep disturbance for people living nearby. Recent research on children’s exposure to aircraft noise found evidence of reduced academic achievement and health damage.

The aviation sector has addressed some of these issues by boosting fuel efficiency through improved engine and plane designs. However, the uptake of sustainable alternative fuels is very slow, and the recent collapse in global oil prices has eased the incentive on airlines to develop biofuel-based renewable fuels. Moreover, jet fuels used on international flights are also exempt from national taxes. Compared to fuels used in other heavily taxed transport modes such as road transport, this tax exemption makes the cost of flying relatively cheaper and the user does not pay for most of the negative impacts on the environment and climate.

Airlines are continuously upgrading their fleets. New planes are much more fuel-efficient and have quieter engines, but replacing the entire fleet by more fuel-efficient aircraft will take time. Newer aircraft fleets have led to reductions in emissions per passenger kilometre, but the pace of growth in recent years and projected growth in the years ahead mean that technological efficiency gains fall short of reigning in the absolute increase in total emissions from aviation.

Tourism and transport

The tourism sector depends on transport, while the demand in the tourism sector contributes to the growth in the transport sector. With raising income levels and decreasing holiday travel costs, more and more people aspire to ‘discover new places’. Globalisation and extensive transport networks potentially turn every location into a holiday destination. More than half of the international tourist arrivals in the world are for holidays and leisure trips.

Although the aviation and cruise sectors are growing, the largest share of trips by tourists is made by car.[1] However, air transport accounts for the largest share of tourism-related GHG emissions, while cruises remain the most GHG emissions-intense mode of transport per kilometre travelled. Furthermore, most cruises start with flights to reach harbours, adding between 10 % and 30 % to the total emissions caused by the cruise.[2]

Europe is a major tourist destination. In 2007, the number of air passengers in Europe was estimated to be around 600 million, 400 million of whom were leisure passengers[3] In 2030, Europe is expected to have international tourist arrivals corresponding to almost 90 % of its population. 

Highways of the sea

Thousands of cargo ships routinely travel long distances on the high seas to move millions of tonnes of goods between continents — everything from fresh fruits and television sets to grain or oil. The maritime transport sector plays a key role in Europe’s economy. Almost 90 % of the EU’s external freight trade is transported by sea making European businesses and consumers heavily dependent on goods imported from the rest of the world. Shipping is seen as the cheapest way to move goods around the world, but the sector remains a highly volatile one, prone to boom and bust economic cycles.

While the sector’s share of GHG emissions is lower than those of road transport or air freight, its environmental impact is nevertheless growing. The shipping industry is estimated to emit around 1 billion tonnes of CO2 per year and this is projected to rise to 1.6 billion tonnes by 2050. The International Maritime Organisation’s (IMO) latest figures show that if no action is taken, GHG emissions from shipping will increase by up to 250 % by 2050, representing 17 % of global emissions.

The sector is heavily dependent on fossil fuels to power its engines, in particular bunker fuel, which is a less refined, more polluting and cheaper mix of oils, including diesel oil, heavy fuel oil and liquefied natural gas.

As ships spend most of their time out at sea, the reporting and analysis of their emissions have been less precise. However, when sailing close to the coast, the impacts of the emissions are clear. The burning of bunker fuels emits sulphur dioxide and nitrogen oxides, causing acid rain and generating fine particles. These pollutants are dangerous for both human health and ecosystems.

Air pollution is only one of the environmental impacts of maritime transport. The sector has faced pressure over recent decades to do more to prevent oil spills, and dumping of waste and other pollutants at sea. Passenger cruise liners have come under increased scrutiny for their environmental impact. Demand for cruises continues to rise, resulting in the construction of megaships, which can carry more than 5 000 passengers and more than 1000 crew, making them floating cities at sea. These ships create large amounts of sewage, garbage, wastewater and air pollution, which critics say poses increased risk to the environment.

Most harbours are not yet equipped to supply electrical power to ships. Consequently, ship engines or on-board generators are always kept running even when moored to meet the ship’s internal energy needs, which in turn worsens air quality in harbour cities. Furthermore, sensitive ecosystems, such as the Arctic and Antarctic or coral reefs, are facing the risk of damage due to increased tourist traffic via cruises.

Although there are no agreed and binding targets, the industry and the IMO have taken some steps to reduce GHG emissions and pollution. New operational measures like slow steaming, sulphur emission control areas, better routing and banning discharges in and around sensitive marine areas are being adopted, and new hull designs to improve fuel efficiency and safety are being embraced. They are also looking at the use of cleaner fuels, including biofuels, as well as electric hybrid propulsion. A new global cap on the amount of sulphur permissible in fuel will be introduced from 2020, limiting the amount of sulphur in fuel to 0.5 %. The EU already restricts sulphur from commercial shipping to 0.1 % in a zone that extends from the English Channel to the Baltic Sea.

Time for change?

Airlines and shipping companies acknowledge these measures will not be enough. The objective of the ‘Paris Agreement’ to limit global average temperature rise to 2 °C above pre-industrial levels, and if possible to 1.5 °C, is not achievable without the full engagement of the international aviation and maritime sectors. Some of the stakeholders in these sectors are already taking action. For example, recognising the concerns linked to their ground operations, some airports are putting in place a series of measures not only to curb noise pollution and GHG emissions, but also to prepare the airport for climate change impacts. Currently, 92 European airports participate in the Airport Carbon Accreditation Programme, 20 of which are carbon neutral.

For sector-wide action, however, the onus is now on the international regulatory bodies. For aviation, the focus has been on the ICAO, members of which are working to reach a climate deal this year. ICAO member states have already agreed to a goal of carbon-neutral growth by 2020 and the ICAO is currently working to bring a ‘global market-based mechanism’ (GMBM) or a global carbon-offsetting scheme online by 2020 to achieve the carbon-neutrality goal. The plan also includes the use of more efficient engines and biofuels. However, access to market instruments is not expected to lead to significant direct emissions reductions from the sector; it will rather enable aviation operators to off-set their increasing GHG emissions by making reductions in other economic sectors. In this case, emissions of air pollutants and noise are expected to continue to increase.

Similarly, the IMO is leading talks between shipping nations on limiting emissions. Several initiatives are on the table, including the creation of a global data collection scheme to improve information on emissions from maritime shipping, an emissions reduction target and a market-based system to achieve the target.

The European Union has already taken measures to slow the growth of emissions by airlines and shipping companies. The EU and EUROCONTROL (the international organisation managing pan-European air traffic) have also been pushing for a more efficient use of European airspace and air traffic management through the Single European Sky initiative. The EU has also worked with the industry on research programmes to make jet engines more environment-friendly in terms of noise and other pollution.

Starting in 2012, GHG emissions from flights within the European Economic Area[4] have been included in the EU’s Emissions Trading System (ETS). The EU exempted flights to and from non-European Economic Area countries up until the end of 2016 to give time for the ICAO to negotiate a global deal.

Similarly, the EU has pushed hard for the IMO to come up with a global approach to reduce pollution. The European Commission is pushing the IMO and industry to adapt new operational measures to improve the energy efficiency of existing ships and the design of new ones. Under a new EU monitoring, reporting and verification regulation, from 2018, large ships (over 5 000 gross tonnes) using EU ports will have to report their verified annual CO2 emissions and other relevant information. The ships will have to monitor and report the amount of CO2 emitted on journeys to, from and between EU ports and also when in EU ports. This reporting system is estimated to cut carbon emissions from journeys covered by up to 2 %.

There are also EU rules in force to tackle sulphur emissions in Europe’s coastal waters and harbours. A European Parliament report has also suggested the maritime transport sector look at finding alternative fuels and other renewable energies to power ships.

Carbon offsetting

Carbon offset programmes, introduced over a decade ago, allow consumers to buy carbon credits to ‘neutralise’ their travel emissions, or emissions produced by shipping. The initial public interest around carbon offsetting seems to have faded. Currently only 2 % of international flights are offset by passengers and this is not expected to rise in future, despite the fact that many airlines and cruise lines continue to offer the service.


[1] Peeters P., Szimba E., Duijnisveld M. (2007) “Major environmental impacts of European tourism transport”, Journal of Transport Geography

[2] Eijgelaar, E., Thaper, C. & Peeters, P. (2010) Antarctic cruise tourism: the paradoxes of ambassadorship, ‘Last chance tourism’ and greenhouse gas emissions. Journal of Sustainable Tourism, Volume 18, Issue 3, pages 337 - 354.

[3] Andreas Papatheodorou, 2010. ‘Aviation and Tourism: Implications for Leisure Travel’

[4] European Economic Area consists of the 28 Member States of the European Union, Iceland, Liechtenstein, and Norway.


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