Incorporating health co-benefits into technology pathways to achieve China's 2060 carbon neutrality goal: a modelling study.

Background: The announcement of China's 2060 carbon neutrality goal has drawn the world's attention to the specific technology pathway needed to achieve this pledge. We aimed to evaluate the health co-benefits of carbon neutrality under different technology pathways, which could help China to achieve the carbon neutrality goal, air quality goal, and Healthy China goal in a synergetic manner that includes health in the decision-making process.

Methods: In this modelling study, we used Shared Socioeconomic Pathway 2 with no climate policy as the reference scenario, and two representative carbon neutrality scenarios with identical emission trajectories and different technology pathways-one was led by renewable energies and the other was led by negative emission technologies. We had three modules to analyse health co-benefits and mitigation costs for each policy scenario. First, we used a computable general equilibrium model that captures the operation of the whole economic system to investigate the carbon mitigation costs and air pollutant emission pathways of different technology portfolios. Second, we used a reduced complexity air quality model to estimate the concentrations of particulate matter in the atmosphere from the air pollutant emission pathways. Finally, we used a health impact evaluation model to estimate premature deaths, morbidity, and the resulting loss of life expectancy, then these health impacts were monetised according to value of a statistical life and cost of illness. We compared the monetised health co-benefits against the corresponding mitigation costs to explore the cost-effectiveness of different technology portfolios. A series of uncertainties embodied in carbon neutrality pathways and models were considered.

Findings: In our models, sole dependence on improving end-of-pipe air pollution control measures is not sufficient for all Chinese provinces to meet the 2005 WHO PM standards (10 μg/m) by 2060. Only a combination of strong climate and air pollution control policies can lead to substantial improvement of air quality across China. If the carbon neutrality pathway led by developing renewable energies was followed, the air quality of all provinces could meet the WHO guideline by 2060. With the realisation of carbon neutrality goals, the total discounted mitigation costs (discount rate 5%) from 2020-60 would range from 40-125 trillion Chinese yuan (CNY), and 22-50 million cumulative premature deaths could be avoided. China has the potential to increase the associated life expectancy by 0·88-2·80 years per person in 2060 versus the reference scenario. The health benefits are higher in the renewable energies-led scenarios, whereas the mitigation costs are smaller in the negative emission technologies-led scenarios. If the value of a statistical life is set higher than 12·5 million CNY (39% of the Organisation for Economic Co-operation and Development value), the health co-benefits will be higher than mitigation costs, even when considering all included uncertainties, implying the cost-effectiveness of China's carbon neutrality goal.

Interpretation: The life expectancy increase from the realisation of China's 2060 carbon neutrality goal could be equivalent to the past 5-10 years of life expectancy growth in China. Choosing an appropriate carbon neutrality pathway affects the health of China's population both today and in the future. Our findings suggest that, if China incorporates health co-benefits into climate policy making and puts a high value on people's health, it should choose a carbon neutrality pathway that relies more on developing renewable energies and avoid over-reliance on negative emission technologies.

Funding: National Key R&D Program of China, National Natural Science Foundation of China, Tsinghua-Toyota Joint Research Fund, Tsinghua-Rio Tinto Joint Research Centre for Resources, and Global Energy Interconnection Group.

Translation: For the Chinese translation of the abstract see Supplementary Materials section.