Global warming and other adverse climate change impacts induced by anthropogenic carbon dioxide emissions are a major public policy concern around the world including transitional economies. This paper, therefore, examines the impacts of market-based economic reforms on per capita CO2 emissions in the European and Central Asian transition economies where environmental degradation was pervasive prior to these reforms. A dynamic panel data model is employed for this purpose for 28 countries covering 22 years from 1990 to 2012. Our overall results suggest that economic openness may not necessarily result in sustainable development although reforms in competition policy and corporate governance were the significant drivers of emissions reductions in the region. Hence, advances in competition policy and governance reforms are desirable given the available scope to extend these reforms. The structural shift to and emergence of light industries also contributed to declining CO2 emissions in the transition process. The direct impact of the Kyoto Protocol in reducing emissions is debatable which also raises doubts on the effectiveness of the Paris agreements.