This study investigates influences of different factors on CO2 emissions of the global electricity generation system. The analysis has been performed through applying an electricity system investment and production optimization model based on linear programming. This model has been calibrated according to the real electricity generation data. The results show that the introduction of a global carbon price of 18 (sic)/ton would lead to a total abatement of several hundreds of million tons in 2006, i.e. 5% reduction of global CO2 emissions compared to a baseline scenario with zero CO2 price. Through a sensitivity study, we show that in addition to the CO2-price, relation between natural gas and coal price is crucial for the abatement achieved through fuel switching. On a long-term horizon, integration of wind is determined as the most economic option to respond to ambitious emissions reduction targets. A wind power capacity of 4913 GW in 2020 and 15729 GW by 2040 allows reducing CO2 emissions by 35% and 78%, respectively, from the level of year 2000 while the CO2-price rises from 18 to 44 (sic)/ton. This can only be achieved if the capacities of cross-border power transmission interconnections are extended far beyond the existing levels. (C) 2011 Elsevier Ltd. All rights reserved.