Historical dynamics of agricultural carbon emissions in the North China plain over the past 300 years

Against the background of national “carbon peaking” and “carbon neutrality” goals, this paper focuses on the North China Plain (covering Beijing-Tianjin-Hebei, Henan, Shandong, Anhui, Jiangsu), reconstructs its nearly 300-year agricultural production dataset using multi-source data and methods of extraction, calibration and interpolation, and establishes a period-specific, county-level carbon emission accounting system. Its innovation lies in constructing a long-time series, high-spatial-resolution dataset and a period-adapted accounting system, breaking the limitations of existing short-term, provincial-scale studies. Results show: (i) Agriculture has long been a carbon sink, with fluctuating net absorption (189.45 × 10 4  t C in early Qing to 417.08 × 10 4  t C in mid-Qing, 294.95 × 10 4  t C in late Qing to 3,831.46 × 10 4  t C in modern times) and rising net absorption intensity (0.09–1.87 t C/hm 2 ). (ii) Crop planting structure, multiple cropping index and high-yield varieties significantly affect carbon sinks. (iii) Per unit yield growth fails to reduce emission intensity, maintaining the “high-input-high-emission” model. These findings help assess the North China Plain’s agricultural carbon mitigation potential and provide a scientific basis for regional low-carbon agriculture.