China’s carbon neutrality agenda unmasks a persistent north-south divide in toxic pollutant reduction

Here, we combine scenario analysis with machine learning to assess the impact of China’s carbon neutrality policy on the reduction of toxic polycyclic aromatic hydrocarbons (PAHs), as quantified by their toxic equivalency emissions (EBaPeq). Using long-term (2000–2023) energy consumption data and provincial projections to 2060, we show that national EBaPeq is expected to peak around 2027 due to policy impacts, and then fall by 45% by 2060. This peak timing proves robust to data uncertainties. However, a pronounced north-south divide persists: northern regions, constrained by coal-dependent energy systems and aluminum-smelting industries, will peak later, whereas central and southern China achieved their peaks before 2012. This regional imbalance in emission intensity per GDP may widen under certain growth pathways. We propose targeted policies—such as cross-regional technology transfer, differentiated transition roadmaps, and improved ecological compensation—to support more equitable and synergistic abatement of carbon and toxic pollutants. China’s polycyclic aromatic hydrocarbons emissions will peak around 2027, then decrease by 2060, and regional disparities in emissions per gross domestic product are likely to persist, according to analysis that uses energy consumption and emissions data and machine learning.