China’s challenges of warming limit: Strategic shift from 2 °C to well below 1.5 °C

By developing an IAM-based multi-model analysis framework, this study explores the significance of limiting warming to below 1.5 °C from 2 °C for China, indicating that the challenge of the goal enhancement may drive China to sustainable transition. In 1.5 °C scenario, with diminishing marginal policy costs, China can further reduce its CO2 emissions via developing technologies and upgrading energy system. In terms of CO2 emissions, under the strengthened warm-limiting target, model-robust conclusions on trajectories and budgets show that the peak and negative-emission shift can be reached in advance, and emissions in the early phase and long term will decline significantly. Some models find that enhancing the goal from 2 °C to 1.5 °C will perform better emission-reducing effect with prominent advantages of technologies. The enhancement in limiting warming will reduce the total energy consumption and increase policy costs. However, the energy system can be reconstructed through early-stage development of negative-emission technologies, e.g., biomass with CCS and late-stage proportions of renewable energy to release the pressure of cutting energy demand. Further, the reinforcing of climate goal from 2 °C to 1.5 °C corresponds to an increase of economic loss, in spite of a deceasing marginal cost.