CCA's compliance with EU law
The general idea of the national CCA is also in accordance with Article 114 TFEU, which regulates the approximation of laws, because Article 114 (5) TFEU allows to introduce national provisions (such as the CCA) based on new scientific evidence relating to the protection of the environment on grounds of a problem specific to the Member State arising after the adoption of the EU harmonisation measure (in a form of directives or regulations mainly). The Member state has a duty to notify the Commission of the envisaged provisions and the grounds for introducing them. As new scientific evidence can be considered, for example, new gases with the greenhouse effect or (scientific) findings that the approximated regulations are not effective thus it is necessary to introduce stricter regulations on national level.
Article 192 TFEU establishes the EU’s competence in environmental policy matters. It should further be noted, namely, that the Lisbon Treaty introduced, in Article 194 TFEU, a brand new chapter regarding energy policies. It is obvious that this chapter could be of important relevance to national Climate Change Act-like laws. Article 194 TFEU enables the EU to accept secondary laws (regulations, directives, decisions) that are not legally based on environmental protection, but on energy policy. If so, Member States will not be allowed to accept and sustain stricter legal regulations than those established by the EU (the rule under Article 193 TFEU does not apply). The only exception from this conclusion is Article 194 paragraph 2 TFEU: “Such measures shall not affect a Member State's right to determine the conditions for exploiting its energy resources, its choice between different energy sources and the general structure of its energy supply, without prejudice to Article 192 (2) ©.”
However, when creating a Climate Change Act Member States should mind the meaning of different legal bases from which EU legal regulations (e.g. directives) arise and which could disable the introduction of certain provisions that fall clearly within the scope of energy policy, in the sense of Article 194 TFEU.