Pathways for decarbonizing China's building sector under global warming thresholds

To achieve the long-term climate targets of limiting global warming to well below 2 ℃ and 1.5 ℃ relative to pre-industry levels, China's building sector must be deeply decarbonized considering its potential of substantial emissions increase. However, how to deploy the energy technologies and how much we need to pay for China's building sector for achieving the global warming targets remain unknown. Here, we develop a bottom-up national energy technology model for building sector (NET-Building) to explore the optimal energy technology pathways, energy demands as well as costs and benefits for decarbonizing China's building sector under 2 ℃ and 1.5 ℃ targets. The results show that to meet the 2 ℃ target, most of fossil fuel-fired end-use devices and all traditional biomass-fired end-use devices need to be significantly reduced for the whole building sector. To pursue a more aggressive 1.5 ℃ climate goal, both proportions of the ground source heat pump and solar thermal water heater need to be drastically boosted and reach 100% in commercial sector by 2050. The decarbonization of China's building sector under 2 ℃ and 1.5 ℃ targets can obtain 44 and 137 trillion CNY net incomes until 2050, respectively.