Worldwide there have been widespread measures (e.g., early retirement of coal-fired power plants, implementation of renewable energy generation, Carbon Capture, and Storage CCS) to promote low-carbon transition in the power sector. (1−4) A growing body of literature has demonstrated how early phaseout of coal-fired power and the limitations of energy storage technology on the large-scale deployment of renewable energy generation may bring about risks such as grid instability, (5,6) stranded asset risks, (7,8) and social instability. (9) Therefore, a set of transition strategies for the power sector is urgently necessary to avoid the risks closely tied to existing climate policy. (10,11) Biomass & coal cofiring with CCS is one of BECCS’s technologies, serving as a viable pathway for achieving low carbon transition and mitigating global warming (12−14) through retrofitting existing coal-fired power infrastructure. (15) Especially against the policy background aiming to decarbonize coal-fired power plants, the Action Plan for Low-Carbon Transformation and Construction of Coal (2024–2027) emphasizes the promotion of retrofitting coal power plants with technologies that involve biomass and coal cofiring. (16) This policy reinforces the significant use of bioenergy as a key strategy in the low-carbon transition of coal power.

However, the implementation of biomass and coal cofiring retrofit (BCCR) may highlight the misalignment between decarbonization and air pollutant abatement. Despite that BCCR contributes to mitigating climate change, excessive coal and bioenergy consumption brings potential environmental and health risks. (17) The deployment of BCCR will help delay the early retirement of coal power plants and retain the original coal power infrastructure, (18) which may sustain and even exacerbate the persistent air pollution in regions with a high proportion of coal-fired power generation, in comparison to a swift phase-out of coal. (19) On the one hand, existing research has verified that compared with other renewable energy such as solar and wind energy, bioenergy may give rise to additional emissions of pollutants such as fine particulate matter (PM2.5), nitrogen oxides (NOx), and sulfur dioxide (SO2), (20,21) which serve as precursors for PM2.5 and ozone formation (22) and pose a certain threat to human health. (23−25) On the other hand, the promotion of BCCR may perpetuate or even exacerbate uneven regional pollution exposure as the disproportionate distribution of existing coal-fired power plants among regions, may pose challenges to just transition in the context of combating climate change. Existing power plants tend to be located on the outskirts of cities or rural areas, where socioeconomically disadvantaged groups reside. (26,27) Additionally, children and the elderly tend to present higher vulnerabilities and sensitivities to pollution exposure. It is imperative to implement more stringent emissions control strategies in advance to mitigate the health risks, as there may exist substantial health burden disparities in different regions.

A growing body of literature has verified how policies aiming to reduce greenhouse gas (GHG) emissions can concurrently reduce air pollution and improve public health, (28−30) with focusing on technologies where decarbonization and air pollutant abatement are aligned such as wind and solar generation technology. (31,32) However, the negative impact of the energy transition pathway to achieve climate goals, particularly regarding environmental and public health impacts, has not been widely discussed and largely depends on the technologies adopted... (33)

Figure 1. Comparison of the future electricity mix in different scenarios toward carbon neutrality. A comparison of the electricity mix among different scenarios and the status in 2020 is conducted based on the GCAM and GCAM-BCC models. Up to 11 generation technologies are shown in the REFERENCE, CN-BASE, and CN-BCCR scenarios respectively, including biomass and coal cofiring power, biomass, coal, gas, nuclear, geothermal, refined liquids, hydro, rooftop_pv, and wind. The electricity supply structure undergoes significant shifts as BCCR is considered under the carbon neutrality target, which reflects the interconnected nature of the energy grid. (a) Future electricity mix in different scenarios towards carbon neutrality in 2030. (b) Future electricity mix in different scenarios towards carbon neutrality in 2040. (c) Future electricity mix in different scenarios towards carbon neutrality in 2050. (d) Future electricity mix in different scenarios towards carbon neutrality in 2060.

Figure 4. Regional distribution of PM2.5-related premature mortalities among different scenarios. (a, b) Present the regional distribution of premature deaths in the CN-BASE scenario (the bottom color of the map) and additional premature deaths in the CN-BCCR scenario (the dot chart) with CLE pollution control strategy in 2030 and 2050, respectively. We (c, d) compare the PM2.5-related premature mortality in CN-BASE and CN-BCCR scenario with different pollution control strategies (CLE, TPC, ULE, and FC). All provinces have been divided into 5 groups based on the quintiles of regional PM2.5-related premature mortalities (Lowest 20%, Second 20%, Third 20%, Fourth 20%, and Highest 20%). (e) Presents the differences in average total population, elderly population, child population, and coal-fired power capacity among the above 5 groups.