Incorporating health co-benefits into regional carbon emission reduction policy making: A case study of China's power sector.

The values of OM emission factors of CO 2 , co-abatement rates per unit CO 2 emission reduction, and the health co-benefits per unit of CO 2 emission reduction in each grid in China. The depth of color indicates the relative size of the health co-benefits. Deeper colors represent higher CO 2 OM emission factors (t/MWh) in (a), higher co-abatement rates of each kiloton of CO 2 emission reduction (tSO 2 /kt CO 2 , tNOx/kt CO 2 , tPM 2.5 /kt CO 2) in (b), (c), and (d), and larger health co-benefits of each kiloton of CO 2 reduction (¥/kt CO 2) in (e). The values in (e) are mean values. The circular diagram in each grid shows the share of trans-grid health co-benefits (%) if carbon emissions are reduced in the respective grid. Tibet is blank due to lack of data. This graphical abstract implies that, if policy makers want to increase synergies between carbon and conventional air pollutants (CAP) reductions, they should allocate more carbon emission reduction targets to those regions with higher CAP co-abatement per unit of CO 2 emission reduction. Therefore, the grids that should take more responsibility to reduce emissions are as follows: the south, northwest, and east grid for SO 2 co-reduction; the northeast, north, and northwest grid for NOx co-reduction; and the northeast, south, and east grid for PM 2.5 co-reduction. However, if policy makers want to increase synergies between carbon emission reduction and health co-benefits, they should allocate more carbon emission reduction targets to those regions with larger health co-benefits per unit of CO 2 emission reduction. Therefore, the grids that should take more responsibility to reduce emissions are as follows: the south, central, east, north, northwest, and northeast grid. Besides, the graphical abstract also implies that, the share of trans-grid health co-benefits due to the same amount CO 2 emission reductions can be as high as 14.1% if CO 2 reduction takes place in the east grid. Therefore, in this study, we advocate that health co-benefits and the trans-regional distribution of health co-benefits should be incorporated into regional carbon emission reduction policy making in order to increase mitigation efficiency. • The health co-benefits per unit CO 2 reduced in China's power grids were quantified. • The difference in health co-benefits per unit CO 2 reduced could reach fivefold. • The share of health co-benefits transfer effect could be as high as 14.1%. • Health co-benefits and their trans-regional distribution should be considered. How to maximize the synergies between CO 2 and conventional air pollutants (CAP) emission reductions have been extensively discussed in previous studies. However, few studies have explored the essential policy concern, which is, how to maximize the social benefits including both carbon mitigation and human health co-benefits from the co-abated conventional air pollutants. Besides, for some sectors that have extensive inter-regional trade, using more low-carbon technologies to produce goods (and thus reducing its own CO 2 emissions) in one region may influence the need of goods imported from another region and consequently the associated conventional air pollutants emissions. Therefore, the health co-benefits may also be transferred to the other regions. This transfer effect has seldom been quantified before. To bridge these research gaps, this paper took China's power sector as an example and quantified the operating margin (OM) emission factors of SO 2 , NO X and PM 2.5 in China's six power grids. Then the co-abatement rates of these three pollutants when reducing each kiloton of CO 2 in different grids were calculated. Finally, considering different grids' meteorological conditions, population densities, baseline incidences, baseline death rates, and the inter-grid electricity trade, this paper computed and compared the values and regional distribution of health co-benefits per kiloton of CO 2 reduced. It is found that grids with the highest co-abatement rates in conventional air pollutants do not necessarily bring maximum health co-benefits. Although the northeast grid could achieve the largest co-reduction in NO X and PM 2.5 , it is the south grid that has the largest health co-benefits. The differences in health co-benefits of the same amount of CO 2 reduced among grids vary as much as fivefold. Besides, the share of trans-grid health co-benefits can be as high as 14.1% if CO 2 reduction takes place in the east grid. Therefore, it is suggested that the health co-benefits of CO 2 reduction and their trans-regional distribution should be taken seriously when making regional carbon emission reduction plans, in order to maximize the social benefits of CO 2 reduction. [ABSTRACT FROM AUTHOR]