Mitigating aviation’s non-CO2 effects in the EU’s Fit for 55 package

The Fit For 55 regulatory package proposed by the European Commission aims at decarbonising the European economy and aligning it with the goals set in the Paris agreement. Whilst decarbonising aviation must be a priority, the sector has an even bigger climate problem which has been flying under the legislative radar for a long time: non-CO₂ effects.

On top of CO₂, aircraft engines emit other gases (NOx, SO2 and H2O) and particulate matter (soot). When released at high altitudes, these emissions affect atmospheric physical and chemical properties, resulting in an increase in greenhouse gases and the potential formation of persistent contrail cirrus, which causes a net warming effect on climate that is bigger than that of CO₂.

But how can Europe act now to mitigate these effects?