In this article we examine the technological feasibility of the global target of reducing GHG emissions to 50 % of the 1990 level by the year 2050. We also perform a detailed analysis of the contribution of low-carbon technologies to GHG emission reduction over mid- and long-term timeframes, and evaluate the required technological cost. For the analysis we use AIM/Enduse[Global], a techno-economic model for climate change mitigation policy assessment. The results show that a 50 % GHG emission reduction target is technically achievable. Yet achieving the target will require substantial emission mitigation efforts. The GHG emission reduction rate from the reference scenario stands at 23 % in 2020 and 73 % in 2050. The marginal abatement cost to achieve these emission reductions reaches $150/tCO(2)-eq in 2020 and $600/tCO(2)-eq in 2050. Renewable energy, fuel switching, and efficiency improvement in power generation account for 45 % of the total GHG emission reduction in 2020. Non-energy sectors, namely, fugitive emission, waste management, agriculture, and F-gases, account for 25 % of the total GHG emission reduction in 2020. CCS, solar power generation, wind power generation, biomass power generation, and biofuel together account for 64 % of the total GHG emission reduction in 2050. Additional investment in GHG abatement technologies for achieving the target reaches US$ 6.0 trillion by 2020 and US$ 73 trillion by 2050. This corresponds to 0.7 and 1.8 % of the world GDP, respectively, in the same periods. Non-Annex I regions account for 55 % of the total additional investment by 2050. In a sectoral breakdown, the power generation and transport sectors account for 56 and 30 % of the total additional investment by 2050, respectively.