The aviation industry can significantly reduce its environmental impact with only minimal changes to aircraft equipment and infrastructure, according to the findings of a new research paper.
Changing air traffic control and flight operations procedures can reduce the industry’s climate impact by up to 20% over the next five to 10 years, researchers from the University of Bristol have found in a paper. published in the journal Aerospace.
Non-CO2 emissions from aircraft account for more than two-thirds of aviation’s net climate impact, but due to the focus on decarbonisation in policy-making – which is necessary to achieve net targets zero – mitigating these emissions is often overlooked, said lead author Kieran Tait.
“Flight route modifications in the form of climate-optimal routes, to avoid climate-sensitive regions, and formation flight, in which two aircraft fly one behind the other (separated from ‘about 2 km) could hold the key to significantly reducing aviation’s climate impact,’ Mr Tait, who has completed a review of the latest science on aviation emissions, said.
Last year, airlines pledged to achieve net carbon emissions from their operations by 2050, aligning the airline industry with the Paris Agreement goals to limit global warming to 1.5°C above pre-industrial levels. Airlines are facing pressure from environmental groups to reduce their carbon footprint and rebuild greener operations after the Covid-19 pandemic.
In October 2021, at the 77th Annual General Meeting of the International Air Transport Association in Boston, USA, the industry lobby group presented plans to achieve this goal through a combination of elimination source emissions (such as the use of SAF and air navigation improvements), carbon offset and capture technologies.
The findings of the research paper echo Iata’s net zero plan which calls for improvements in flight operations and operational efficiency, with a particular focus on improving air traffic management.
There are two main contributors to aviation’s non-CO2 climate impact – aircraft contrails and nitrogen oxide (NOx) emissions, the paper explains.
The warming effect of non-CO2 emissions strongly depends on the chemical and meteorological state of the atmosphere at the time they are released.
Contrails account for 51% of aviation’s total climate impact. Where the air is very cold and humid, the water vapor in the contrails condenses around the particles to form ice crystals which trap heat and have a net warming effect.
NOx emissions react with chemicals in the atmosphere to generate ozone and reduce methane. However, ozone generation tends to outweigh methane reduction, resulting in a net warming effect.
“While a climate-optimal route may require a longer flight, and therefore 1-2% additional fuel consumption, avoiding climate-sensitive areas could actually reduce a flight’s overall impact on the environment. climate by about 20%,” Tait said.
“In formation flight, the follower aircraft flies in the wake of the lead aircraft, receiving lift which reduces the required lift and results in a five to eight percent decrease in fuel burn. It also has the advantage from overlapping aircraft exhaust plumes and the buildup of emissions they contain.”
The next step is to analyze global air traffic data to identify high-density airspace hotspots (such as along flight corridors), where implementation of the formation flying concept would be the better suited, Mr. Tait said.
This document brings together the latest evidence of the aviation industry’s climate impact and concludes: “This is how we can make a real and meaningful difference, right now.”
“The aviation industry has much to gain by taking these findings into account and making small but critical changes to air traffic control and flight operations that will have such a significant impact,” said Steve Bullock, Associate Professor of Aerospace Engineering, which supervised Dr. Tait’s research.
Updated: September 04, 2022, 08:20