January 2025: The policy landscape is forming around aviation’s CO2 emissions, but there is still a lack of policy to address its non-CO2 climate impacts – mainly in the form of contrails.

Reducing contrails – those silver streaks that form across cold, humid skies - is the closest thing we have to a silver bullet to dramatically reduce the climate impact of aviation.

Opportunity Green and Small World Consulting’s latest briefing provides guidance for policymakers on reducing contrail impact and finds that:

• Reducing contrail clouds and their warming effect can be actioned now

• Action on contrails requires less than 2% of flights to be rerouted

• Technological solutions are available

• There is already support and co-operation of key players in the aviation industry, such as academics, flight-path providers as well as some airlines.

The report sets out these five key recommendations to policymakers:

1. The aviation industry must be compelled to prioritise contrail management to reduce its climate impact now, since any emission reduction enabled by Sustainable Aviation Fuels will only be realised in decades to come.

2. The aviation industry must monitor non-CO2 emissions from all flights and to collect and analyse data on weather conditions, particularly high-altitude humidity measurements.

3. Contrail management must be a mandatory part of aviation technology planning. Some aviation companies have made small adjustments to flight paths, timings and fuel costs of a very small percentage of flights, resulting in dramatic contrail reductions.

4. Set fair payments for emissions impact by taxing frequent flyers, private aircraft use and damaging long-haul flights, and use these funds to support the aviation industry in effective contrail management.

5. Engage with the best-practice partnerships, such as the Contrail Impact Task Force, to bring policymakers together with the aviation industry, technology providers, aircraft and engine manufacturers, and academics who are already researching and trialling contrail avoidance.

Read the report in full below.