Future changes in the meteorological potential for winter haze over Beijing during periods of peak carbon emissions and carbon neutrality in China projected by Coupled Model Intercomparison Project Phase 6 models

Abstract

AbstractHazy conditions have a significant impact on the environment and societal development. Their occurrence and persistence depend largely on climatological conditions, including the important role of climate change. Based on monthly data from 15 Coupled Model Intercomparison Project Phase 6 (CMIP6) models under three Tier 1 scenarios (SSP1–2.6, SSP2–4.5, and SSP5–8.5), the meteorological potential for winter haze pollution over Beijing was assessed during periods of peak carbon emissions (PCP; 2021–2030) and carbon neutrality (approximate net‐zero emissions) (PCN; 2051–2060) in China. The results show that a possible high‐emission strategy during PCP may not obviously enhance winter hazy conditions over Beijing in the near future. Rather, the high‐emission scenario in this period may decrease the meteorological potential that is favourable for the enhanced Beijing haze pollution by inducing a Northeast Asia cyclonic anomaly, compared to situations under SSP2–4.5, with medium emissions. Further analyses indicated that, under the continued sustainable pathway (SSP1–2.6 in PCN plus SSP1–2.6 in PCP; the better pathway simulating the effects of approximate net‐zero emissions during PCN through model results), atmospheric conditions such as the East Asian winter monsoon as well as decadal oceanic forcings of the mega‐El Niño and the warm Atlantic Multidecadal Oscillation, which are conducive to more frequent Beijing haze, are significantly suppressed in the farther future PCN. Under such circumstances, in situ haze pollution is highly repressed, suggesting a critical and positive role for the low‐carbon policy advocated by China during PCN in suppressing longer‐term hazy conditions over Beijing. In contrast, Beijing haze pollution during PCN is frequent under the discontinued sustainable pathway (SSP2–4.5/SSP5–8.5 in PCN plus SSP1–2.6 in PCP). Our findings demonstrate the possible insignificant impact of the high‐emission strategy of China during the near‐future PCP on Beijing haze exacerbation, and an important role for carbon neutrality advocated by China to suppress the haze potential in the farther future PCN, highlighting the significance of future pathway selections.