At the upcoming UN climate conference COP29 in Baku, researchers will introduce cost-effective methods to mitigate the climate impact of jet contrails. A new study reveals that modifying flight paths could reduce warming effects by over 50% for less than £4 per flight. Contrails, which create artificial cloud layers that trap heat, can double the warming caused by aviation’s fossil fuel use. The majority of contrail warming originates from just 3% of flights, highlighting the potential for significant climate benefits through simple changes in aviation practices.