Contrail Avoidance: Can Business Jets Fly Higher to Reduce Climate Impact?

A recently conducted environmental study by 4AIR, an aviation sustainability company, assessed that small altitude adjustments on business aviation flights could significantly reduce the environmental impact of contrails.  

The study, which lasted one year and encompassed 16,000 flights and over 27,000 flight hours, found that by adjusting on even a fraction of the flights involved, 50 out of the 16,888, the non-CO2 emission impact would have been reduced by more than 50%. 

Contrails are produced when hot water vapour emitted from aircraft engines rapidly cools at higher altitudes. Depending on the time of day, aircraft contrails can linger and absorb heat that would otherwise be radiated back into space. Some studies reveal that contrails can contribute to two-thirds of the aviation industry's warming impact.  

4 Air President Kennedy Ricci said, "The results of this study demonstrate both the challenges and opportunities with reducing aviation's footprint from contrails."   

"Effectively reducing our contrail warming impact requires considering contrails on every flight, but successfully avoiding on just a handful of flights would have a major impact, potentially without CO2 trade-offs."  

Contrails can be formed at the upper end of the service ceiling of commercial aircraft. However, business aircraft have higher service ceilings and are capable of flying higher than the formation region. This adjustment can reduce their CO2 emissions and contrail impact.  

According to the study, the average contrail was estimated to persist for around 2.5 hours, but more impactful warming came from contrails that persisted for around 6.5 hours. 

4Air's contrail avoidance pilot program, in collaboration with Flexjet, focused on optimising flight paths to minimise the time flights spent flying in contrail-forming regions. The flight paths were adjusted to modify cruising altitudes, and notes were shared with pilots to calibrate climbs and descents, ensuring minimum time was spent in contrail-forming regions.  

Brookfield Aviation International believes that with additional research and collaboration, adjustments in altitude could potentially become a potent tool for minimizing the environmental impact of business aviation.