Meeting the EU 2°C climate target: global and regional emission implications

Meeting the EU 2°C climate target: global and regional emission implications This report presents a set of multi-gas emission pathways for different CO2-equivalent concentration stabilization levels, i.e. 400, 450, 500 and 550 ppm CO2-equivalent, along with an analysis of their global and regional reduction implications and implied probability of achieving the EU climate target of 2°C. The effect of different assumptions made for baselines, technological improvement rates, or delay of global action on the resulting emission pathways is also analysed. For achieving the 2°C target with a probability of more than 60%, greenhouse gas concentrations need to be stabilized at 450 ppm CO2-equivalent or below, if the 90% uncertainty range for climate sensitivity is believed to be 1.5 to 4.5°C. A stabilization at 450 (400) ppm CO2-equivalent requires global emissions to peak around 2015, followed by substantial overall reductions in the order of 30% (50%) compared to 1990 levels in 2050. In 2020, Annex I emissions need to be approximately 15% (30%) below 1990 levels. Non-Annex I emissions may increase compare to the 1990 levels, but not compared to their baseline emissions (15-20% reduction). A further delay in peaking of global emissions by 10 years doubles maximum reduction rates to about 5% per year, and very likely leads to high costs. In order to keep the option open of stabilising at 400 and 450 ppm CO2 equivalent, the USA and major advanced non-Annex I countries will have to participate in an agreement aimed at reductions within 10-15 years. Keys words: multi-gas emission pathway, climate target, post-2012 commitments Netherlands Environmental Assessment Agency page 3 of 44