If the aviation sector was a country, it would be among the world’s top 10 greenhouse-gas emitting nations. Air travel is one of the most polluting modes of travel for its relatively higher carbon dioxide and nitrogen oxide emissions and the effects of vapour trails and gases it deposits in the atmosphere.
But even within air travel, private jets and chartered planes have a higher carbon footprint per passenger. According to a 2021 report of the European Federation for Transport and Environment, private jets are five- to 14-times more polluting per passenger than commercial flights and 50-times more than trains.
A recent study in Nature reported emissions increased by 46% between 2019 and 2023 especially thanks to private aviation. The number of aircraft increased from 25,993 in December 2023 to 26,454 in February 2024, and is expected to grow further. According to the paper, “Private aviation contributed at least … about 3.6 tonnes CO2 per flight.”
More millionaires in India
As of March 2024, 112 private planes were registered in India. According to the paper, India has very few aircraft per lakh population (0.01) compared to Malta (46.51), the U.S. (5.45), Switzerland (3.76), the U.K. (0.78), Brazil (0.43), France (0.36), and Russia (0.1). China has a comparable 0.02.
“But India is actually among the top 20 countries in terms of private aircraft ownership and the highest among low-middle-income countries,” Ramya Natarajan, a research scientist at the Centre for Study of Science, Technology, and Policy (CSTEP), a think-tank in Bengaluru, said. “This isn’t surprising because India, while still a developing country, has the third highest number of billionaires in the world and also has a rapidly growing millionaire population.”
Despite nascent efforts to decarbonise the aviation industry, solutions like sustainable aviation fuels (SAFs), hydrogen, and electrification haven’t been easy to implement at a large scale.
Private flight usage
In the study, researchers from institutes in Sweden, Germany, and Denmark analysed flight data from the ADS-B Exchange platform and focused on five recent global events accompanied by international travel.
These events were the World Economic Forum in Switzerland; the Super Bowl in the U.S.; the COP28 climate talks in the U.A.E.; the Cannes Film Festival in France; and the 2022 FIFA World Cup in Qatar. In many cases, the researchers found the same aircraft units were used for these events.
Some 47% of all these flights were for distances shorter than 500 km. Around 19% were in fact for distances shorter than 200 km; many of them were actually empty or used to deliver goods. About 5% of the flights spanned less than 50 km — a distance otherwise easily covered by road or rail.
The study also reported that the use of private aircraft for leisure destinations like Ibiza in Spain and Nice in France peaked in June-August, which is summer in the northern hemisphere, and especially over the weekends.
Around 69% of private aviation was concentrated in the U.S.
The researchers also estimated that another 8,500 jets will be delivered to private parties in the next 10 years, although how many will end up in India is unknown. “How many additional private flights might be added every year as India becomes a wealthier, developed country? Can India afford to take the U.S. route? What would the overall impact of such lifestyle choices be?” Natarajan asked.
Air travel and India’s emissions
In the last decade, the Indian government launched the policies ‘Ude Desh Ka Aam Nagrik’ (UDAN) to enhance rural connectivity and ‘Nextgen Airports for Bharat Nirman’ (NABH) to increase airport capacity by more than five times.
Indian airplane operators have also been testing low carbon fuels. In 2018, for example, SpiceJet operated a flight from Uttarakhand to New Delhi on aviation fuel blended with oil from seeds of the jatropha plant, to the tune of 25% by volume. In 2023, Air Asia flew a flight from Pune to New Delhi powered by SAF blended with aviation turbine fuel (ATF) based on indigenous feedstock and supplied by the Indian Oil Corporation, Ltd. But these attempts have not translated into the commercialisation of SAF due to its limited availability and efficiency. According to one April 2024 estimate, it also costs “at least 120%” more than conventional jet fuel for reducing emissions by at least 27%.
Apart from SAFs, both experts and lawmakers have discussed hydrogen and electrification as possible alternatives to kerosene, which is used in aviation for its high energy density. Hydrogen packs three-times more energy in the same mass but handling it is a nightmare. Engineers will need to redesign, remodel, and restructure aircraft bodies as well as the fuel storage, transportation, and fuelling facilities at airports to use hydrogen-based fuels in aviation. Likewise, electrification is currently a poor solution due to issues of battery weight, flight stability, and its dependency on other economies for its raw materials, industry experts have said.
“In India, the alcohol-to-jet pathway seems most likely in the medium term, given that we already have a good ethanol production supply chain,” Natarajan said. “However, this should be carefully planned to avoid negative land-use change and groundwater implications. A demand for SAF should not incentivise increased cultivation of sugarcane or maize. Instead, only surplus sugar should be used.”
However, Natarajan added, the work of her and her peers at CSTEP suggests there is hope. “If by the year 2050, only surplus sugar is converted to ethanol and ethanol is fully used to make aviation fuel, instead of blending with petrol as we do currently, then we can meet almost 15-20% of the aviation fuel demand of 2050,” she said.
Monika Mondal is a freelance science and environment journalist.
Published – December 18, 2024 05:30 am IST
