Assessment of the emission reduction target of halving CO2 emissions by 2050: Macro-factors analysis and model analysis under newly developed socio-economic scenarios

摘要: Abstract This paper assesses the global emission reduction target of halving CO 2 emissions by 2050. First, future GDPs with specific uncertainty ranges were developed. The Kaya identity and developed GDP outlook indicate that 2050, which corresponds to almost 450 ppm-CO eq. stabilization, requires an improvement approximately four times as large historical intensity rate on average up if loss should remain within a few percent potential baseline GDP. In addition, energy-related reductions assessed using energy systems model. Marginal abatement cost is over 470 $/tCO for 2050 relative 2005 even under lower scenario technology improvements. Great challenges will have be met achieving Realistic alternative scenarios explored in two ways; 1) more innovative technological development than any present imaginable development, and/or drastic social innovations are needed cheaper carbon costs, e.g., tens US$ per tonne , 2) modest targets, 550 ppm-CO eq., adaptation measures considered.