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The effects of aviation on climate pose unique policy challenges. A large fraction of the CO₂ emissions (65%) is international and not (explicitly) included in the Paris Agreement. The interpretation of Article 4.1 on achieving a “balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases” is ambiguous in the context of aviation because of the substantial non‐CO₂ effects associated with the sector. For the achievement of the temperature goal in Article 2, both CO₂ and non‐CO₂ effects are important. The non‐CO₂ effects contribute 66% of the sectoral total climate effect (in terms of Effective Radiative Forcing; ERF) at present, with significant uncertainties. The largest of these non‐CO₂ effects, contrail‐cirrus and the net‐effect of NO _x , are not caused by direct greenhouse gas emissions, representing another ambiguity as to whether they should be included in the balance concept …