This study analyzes CO, emissions reduction targets for various countries and geopolitical regions by the year 2030 to stabilize atmospheric concentrations of CO2 at 450ppm (550ppm including non-CO2, greenhouse gases) level. It also determines CO2 intensity cuts that would be required in those countries and regions if the emission reductions were to be achieved through intensity-based targets without curtailing their expected economic growth. Considering that the stabilization of CO, concentrations at 450ppm requires the global trend of CO2 emissions to be reversed before 2030, this study develops two scenarios: reversing the global CO2 trend in (i) 2020 and (ii) 2025. The study shows that global CO2 emissions would be limited at 42 percent above 1990 level in 2030 if the increasing trend of global CO2, emissions were to be reversed by 2020. If reversing the trend is delayed by 5 years, global CO2 emissions in 2030 would be 52 percent higher than the 1990 level. The study also finds that to achieve these targets while maintaining expected economic growth, the global average CO2 intensity would require a 68 percent drop from the 1990 level or a 60 percent drop from the 2004 level by 2030. (c) 2008 Elsevier Ltd. All rights reserved.