A coalition of leading aviation and climate scientists come together in the closing days of the COP29 conference in Azerbaijan to call for more action on reducing warming contrails. Download the open letter / Contrails - the white lines in the sky created by planes - have a net warming effect on the planet, estimated to be at least as important as the one caused by aviation’s CO2 emissions. The climate impact of these effects was first recognised by the IPCC 25 years ago. Nonetheless, little effort has been made in the last decades to reduce them. This is why a coalition of over 50 scientists from across the world are gathering together to call upon global decision makers to implement solutions to tackle contrails - without these coming at the expense of decarbonisation efforts. (....)