In February 2009, the European Union Directive 2008/101/EC was approved, clarifying how emissions from the aviation sector will be included in the European Union Emissions Trading Scheme (EU ETS). According to this directive, starting from 1st January 2012, all aircraft operators (nearly 4000), flying to or from any airport in EU territory will be included in EU ETS. This dissertation aims to provide qualitative and quantitative information about the consequences for aviation industry to be included in European Union Emissions Trading Scheme (EU ETS) for the first trading period (2012). In this study, with empirical data, a scenario approach has also been used to quantify the potential 2012 CO2 emissions from aviation industry. So that, a scale of the possible total financial burden that aviation sector will be under for their CO2 emissions in the first trading period of EU ETS (2012) is calculated. According to the calculations, 2012 CO2 emissions of the flights covered under EU ETS can vary from 231.242 million tonne of CO2 to 277.036 million tonne of CO2 and the cost of 2012 CO2 emissions for the aviation sector can be between 967.47 million Euro and 2.54 billion Euro.