Reduction targets under three burden-sharing schemes for 50% global GHG reduction toward 2050

GHG emission reduction targets for 230 countries/regions in the world are estimated under the overall target of a 50% global reduction by 2050 compared with 1990. Three burden-sharing schemes, Emission per capita (pCAP), Emission per GDP (pGDP), and Cumulative emission per capita (pCUM), are taken into account. Future GDP in the 230 countries/regions is projected under two future scenarios, the advanced society scenario (ADV) and conventional society scenario (CNV). Differences in reduction targets between GHG total and GHG excluding LU, different target years, and the required speed of improvement of GHG/GDP are also investigated. The global GDP growth rate for 2010–2050 is 3.39% under the ADV scenario and 2.23% under the CNV scenario. Under the ADV scenario, the ratio of GDP per capita of Annex I countries to that of non-Annex I countries converges to 3.4 in 2050 from 13.0 in 2005. The reduction targets for pCAP, pGDP, and pCUM in 2050 are respectively 83%, 58%, and 95% for Annex I, and 42%, 57%, and 34% for non-Annex I. In the case of pGDP, Annex I has a high reduction target under the ADV scenario, while non-Annex I has a high reduction target under the CNV scenario.