"Decarbonizing" the world's energy matrix is the strategy being implemented by most countries to reduce CO2 emissions and thus contribute to achieve the ultimate objectives of the Climate Convention. The evolution of the carbon intensity (I-c=CO2/GDP) in the period 1990-2007 was encouraging but not sufficient to reduce the growth of carbon emission. As a result of COP-15 in Copenhagen these countries (and regions) made pledges that could lead to more reduction: for the United States a 17% reduction in CO2 emissions by 2020 below the level of 2005: for the European Union a 20% reduction in CO2 emissions by 2020 below the 1990 level: for China a 40-45% reduction in the carbon intensity and for India a 20-25% reduction in carbon intensity by 2020. We analyzed the consequences of such pledges and concluded that the expected yearly rate of decrease of the carbon intensity follows basically the "business as usual" trend in the period 1990-2007 and will, in all likelihood, be insufficient to reduce carbon emissions up to 2020. (C) 2010 Elsevier Ltd. All rights reserved.