The contribution reflects on the importance and specificities of lawmaking on the climate challenge at the level of Member States, in the specific context of today and in due regard of the new legislative developments and targets adopted by the European Union. It discusses the possible appraisals and declinations of ownership in relation to the climate challenge. It also observes how the content of climate laws has recently evolved in Europe and tries to explain the reasons but also consequences of the quite large margin of appreciation left to Member States on the very question of adopting new laws and possibly new targets at their own level on the climate challenge.