Jets And Pollution: Understanding Their Environmental Impact

Jets are a significant contributor to climate change, with aviation accounting for about 2.8% of the CO2 emissions driving climate change. Private jets, in particular, have a disproportionate impact on the environment, emitting an estimated two tonnes of CO2 per hour of flight. This is especially notable considering that the average person in the EU emits 8.2 tCO2eq over the course of an entire year. With the growth in passenger traffic and jet fuel consumption, the impact of jet pollution on the environment is a critical issue that requires attention and action.

Private jets are 5 to 14 times more polluting than commercial flights

Aircraft contribute significantly to climate change through the emission of greenhouse gases, including CO2, nitrogen oxides, and vapour trails. Private jets, in particular, have come under scrutiny due to their disproportionate impact on the environment.

In 2019, private jets accounted for one-tenth of all flights departing from France, with half of these travelling less than 500 km. Private jets are twice as likely to be used for very short trips (less than 500 km) within Europe compared to commercial flights. This trend is concerning given that private jets are significantly more polluting than commercial alternatives.

A 2021 report from the European Federation for Transport and Environment found that private jets are 5 to 14 times more polluting per passenger than commercial flights. This disparity is expected to increase as private jet users transition to larger and more polluting aircraft. Additionally, private jets emit 50 times more pollution than trains, further highlighting their detrimental environmental impact.

The high level of pollution associated with private jets can be attributed to the variety of gases released and the altitude at which they are emitted. The greenhouse effect is stronger at higher altitudes, exacerbating the impact of emissions. Furthermore, private jets often operate on short-haul flights, which are particularly inefficient in terms of fuel consumption and emissions per passenger.

To address the environmental impact of private jets, several measures have been proposed. These include levying ticket taxes on private flights, similar to those implemented by Switzerland, encouraging the development and adoption of zero-emission aircraft, and imposing fuel taxes on fossil-fuel private jets based on flight distance and aircraft weight. By implementing such measures, it is hoped that the pollution caused by private jets can be mitigated, contributing to the global effort to combat climate change.

The US leads in per capita jet fuel consumption

The US jet fuel consumption is driven primarily by commercial passenger flights, which accounted for an estimated 73% of total jet fuel usage in January 2020. While the number of commercial flights decreased during the pandemic, with a 51% decline in flight volume between January and July 2020, the demand for jet fuel in the US has recovered faster than in many other major aviation markets. This recovery is reflected in the increasing number of passengers and the efforts of airlines to ensure full flights.

The aviation sector's emissions have a significant impact on climate change. Aircraft burn fossil fuels, releasing CO2 and contributing to global warming through nitrogen oxides (NOx), vapour trails, and cloud formation at high altitudes. The use of jet fuels with high aromatics and naphthalene concentrations increases soot formation, further exacerbating the problem. Additionally, emissions from aviation have been growing faster than any other mode of transport, doubling between 1990 and 2019.

To address the environmental impact of aviation, alternatives such as e-fuels (e.g., power-to-liquid and e-kerosene) and zero-emissions aircraft (hydrogen or electric planes) are being explored. However, these alternatives require significant funding and advancements to become fully operational. In the meantime, reducing corporate and private jet travel can significantly lower aviation emissions. The COVID-19 pandemic demonstrated that many work-related flights are unnecessary, and by reducing corporate travel to 50% of pre-COVID levels, Europe could cut CO2 emissions by 32.6 MtCO2 by 2030.

Aviation emissions are growing faster than any other mode of transport

Aviation emissions are a significant contributor to climate change. Airplanes burn fossil fuels, releasing CO2 emissions and causing strong warming non-CO2 effects due to nitrogen oxides, vapour trails, and cloud formation at high altitudes. These non-CO2 effects have a greater impact on global warming than aircraft CO2 emissions and were responsible for two-thirds of aviation's climate impact in 2018.

Aviation emissions have been growing faster than any other mode of transport. Between 1990 and 2019, emissions more than doubled, increasing from 1.5% of all European emissions in 1990 to 4.7% in 2019. The sector is expected to fully recover from the Covid-19 pandemic as early as 2024, and without intervention, emissions could double again by 2050. This growth will have a substantial impact on the remaining carbon budget, with the sector potentially consuming over 10% of the budget to stay below 1.5°C of warming.

Several factors contribute to the increasing aviation emissions. Firstly, the United States dominates the global market for per capita jet fuel consumption, with usage six times the world average and 37.5 times that of India. Secondly, the sheer size of the US air traffic system means that even modest growth in passenger traffic will result in a significant increase in overall emissions. By 2041, annual domestic enplanements in the US are projected to reach 1.26 billion, a 55% increase compared to 2019 levels.

To address the issue of growing aviation emissions, various strategies can be implemented. One approach is to reduce corporate travel, which can significantly lower CO2 emissions. For example, decreasing corporate travel to 50% of pre-COVID levels in Europe could result in a reduction of up to 32.6 MtCO2 by 2030, equivalent to taking 16 million polluting cars off the road. Additionally, the development and adoption of alternative fuels, such as e-fuels like power-to-liquid and e-kerosene, can play a crucial role in reducing emissions. However, these alternatives require significant amounts of renewable energy and face challenges in sustainable scaling.

While the transition to cleaner fuels is important, it is also crucial to recognize the immediate impact of flying less. As Milan Klöwer, a postdoctoral researcher and climate scientist at the University of Oxford, demonstrates through his preference for trains over planes, reducing the number of flights is an effective way to lower emissions in the critical years ahead.

E-kerosene is a potential zero-carbon alternative fuel

Aviation is a significant contributor to global CO2 emissions, with the sector creating 13.9% of the emissions from transport in the EU in 2017. Worldwide, aviation accounts for 2% of all carbon dioxide (CO2) emissions and 12% of all CO2 emissions from transportation. In addition to CO2 emissions, aviation also has strong warming non-CO2 effects due to nitrogen oxides (NOx), vapour trails, and cloud formation triggered by the altitude at which aircraft operate. These non-CO2 effects contribute twice as much to global warming as aircraft CO2 emissions and were responsible for two-thirds of aviation's climate impact in 2018.

To mitigate the impacts of climate change, it is essential to decarbonize the aviation sector. E-kerosene, or Sustainable Aviation Fuel (SAF), is a major development in this journey towards more sustainable aviation. This innovative fuel type is synthesized from carbon-neutral sources, primarily renewable hydrogen and biogenic carbon dioxide, providing an eco-friendly alternative to conventional jet fuel derived from fossil resources. Unlike traditional jet fuel, e-kerosene is produced through a process powered by renewable energy. The key components are renewable hydrogen and carbon dioxide, which can be captured from biogenic sources.

E-kerosene has the potential to be a zero-carbon alternative fuel, as it does not produce CO2 from combustion. It has a higher energy content per weight than traditional jet kerosene, providing superior cooling properties for operation at high speeds and high combustor temperatures. Additionally, e-kerosene can be used directly in existing aircraft engines and infrastructure, meaning no substantial modifications are required for its use. This flexibility allows for multiple products from various feedstocks and production technologies. For example, SAF can be produced from non-petroleum-based renewable feedstocks such as food and yard waste, woody biomass, and fats/greases/oils.

However, it is important to note that e-fuels like e-kerosene require enormous amounts of renewable energy, and their environmental effectiveness depends on the source of the CO2 required to produce them. Nevertheless, they present the best near-term opportunity to meet the aviation industry's goal of reaching net-zero carbon by 2050. The Sustainable Aviation Fuel Grand Challenge, announced in 2021, aims to expand domestic consumption of SAF to 3 billion gallons in 2030 and 35 billion gallons in 2050 while achieving at least a 50% reduction in lifecycle greenhouse gas emissions.

The EU will monitor non-CO2 emissions on flights from 2025

The aviation industry is a significant contributor to climate change. Airplanes burn fossil fuels, releasing CO2 emissions and causing strong warming non-CO2 effects due to nitrogen oxides (NOx), vapour trails, and cloud formation. These non-CO2 effects have been known to contribute twice as much to global warming as aircraft CO2. In fact, a study from 2023 found that they could be responsible for 57% of the aviation industry's warming impact, more than the CO2 emissions from burning fuel.

To address the issue of non-CO2 emissions, the EU will implement a Monitoring, Reporting, and Verification (MRV) system from January 2025. This system will require airlines to measure and report non-CO2 emissions, including contrails, nitrogen oxides, and sulphur. By collecting data on flight routes and adopting clean fuels, airlines can significantly reduce non-CO2 pollutants. However, the EU has faced criticism for excluding long-haul flights from the initial scope of its monitoring scheme, which will only cover flights within the European Economic Area, the UK, and Switzerland, representing only 33% of Europe's aviation-related contrail impact.

The decision to exclude long-haul flights is a result of strong lobbying by legacy airlines, and it delays the EU's progress in understanding and reducing contrails. Nevertheless, the EU's monitoring system is a step forward in addressing the climate impact of aviation. It is important to note that solutions like clean fuels, rerouting flights, and reducing corporate travel can also play a significant role in mitigating the industry's warming impact.

While the EU focuses on monitoring non-CO2 emissions, it is also essential to address the impact of private jets, which are significantly more polluting per passenger than commercial flights. Private jets emit approximately two tonnes of CO2 per hour, contributing disproportionately to the environment. With the aviation sector expected to fully recover from the Covid 'shock' by 2024, addressing both CO2 and non-CO2 emissions is crucial to combat climate change.

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