Atmospheric stabilization of CO2 emissions: Near-term reductions and absolute versus intensity-based targets

This study analyzes CO₂ emissions reduction targets for various countries and geopolitical regions by the year 2030 to stabilize atmospheric concentrations of CO₂ at 450 ppm (550 ppm 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 CO₂ concentrations at 450 ppm 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.