More studies on contrail impact needed
The International Air Transport Association (IATA) recently released a new report, Aviation Contrails and their Climate Effect: Tackling Uncertainties and Enabling Solutions, on the need to deepen the understanding of aviation contrails (the white vapour trails often seen streaming behind aircraft flying at high altitude) and their climatic impact.In summary, the report stated that aviation's environmental impact extends beyond CO² emissions, encompassing non-CO² effects like contrails and nitrogen oxides (NOx) that contribute to global warming.
According to the report, persistent contrails, forming in ice-supersaturated areas, can evolve into cirrus clouds, reflecting sunlight during the day and trapping heat at night, ultimately warming the climate.
However, uncertainties persist in predicting their formation and impact.
The report stated that efforts to minimise contrail-induced warming are underway in the aviation community, comprising industry, governments, academia, and research bodies. “The focus is on understanding and mitigating contrail formation, necessitating synergy between research, technology, and policy.”
Furthermore, “current understanding acknowledges contrail complexity and gaps in scientific knowledge, particularly regarding formation and climate impact due to limited real-time atmospheric data”.
IATA said that initiatives involve collaborations to gather data and trial methods like altered flight paths and alternative fuels. “However, challenges remain due to atmospheric variability and localized contrail occurrence.”
According to the report, advancements in humidity sensors on aircraft are seen as pivotal for better contrail prediction, adding that ongoing research aims to enhance sensor technology for improved data collection and model validation.
Short-term actions prioritise reducing CO² emissions while continuing scientific research and improving climate models, while mid-term efforts focus on data standards, model validation, and aircraft design for meteorological observations. Longer-term strategies aim to expand data collection globally and understand the non-CO² effects of alternative fuels.
In light of this, IATA urged stakeholders to strengthen the integration of technological innovation and regulatory frameworks to effectively reduce aviation's climate footprint. “Monitoring, reporting, and verification schemes must address current scientific gaps for meaningful emissions reduction.”
In conclusion, while progress has been made in understanding aviation's non-CO² impacts, concerted efforts are needed to bridge scientific uncertainties and implement effective mitigation strategies. “Collaboration across sectors is essential for achieving meaningful progress in reducing aviation's climate impact.”