From 2012 international aviation is to be included in the European Union Emission Trading Scheme (EU ETS). The EU ETS has no differentiation between the airlines which means that the trading scheme applies to all airlines regardless of the nationality and business model. Several non-EU states and airlines have opposed the inclusion because according to them the inclusion contravenes international law and they urge the EU and its member states to refrain from including the aviation in the EU ETS. In addition inter alia China Air Transport Association has claimed that the inclusion gravely violates the principle of common but differentiated responsibilities. The purpose of thesis was to give an overview of the existing legal frameworks in the field of climate change and international aviation and analyse in more detail the role and status of the principle of common but differentiated responsibilities and the inclusion of aviation from the non-EU states point of view. The conclusion of the thesis is that there exists so far no clear answer to the question of violation of the principle but as per to Advocate General Kokott`s opinion, it can be set to be in line with the international regulations. It can also be concluded that the interpretation of the principle of common but differentiated principle and also the term developing countries should be changed as they do not fit as such to today’s climate change politics. This is because they rely on the historical contribution to climate change but do not take into account how much the country, especially emerging economies such as China, do emit at moment and how capable they are to mitigate climate change.