<p>Since their emergence, humans have continuously modified land cover and atmospheric composition. These modifications significantly modulate the surface energy balance, the material cycles (e.g., carbon, nitrogen, and water), and the surface roughness, thereby influencing climate change processes. Human activity parameterization serves as a critical bridge coupling human activities with climate system modeling. Its scope has progressively expanded from Land Use and Land Cover Change (LULCC) to multiple forms of human activities, including land-use intensity (e.g., multiple cropping, irrigation, grazing, and fertilization) as well as anthropogenic fire activities. Meanwhile, its representation has evolved from simple, empirically and statistically based descriptions toward more process-driven parameterization schemes. However, current parameterization approaches still suffer from data scarcity, a high level of uncertainty, and excessive simplification. These issues not only undermine the reliability of modeling results but also increase uncertainty in the detection and attribution of human contributions to climate change. To address these challenges, future research needs to focus on developing high-resolution datasets, advancing multi-process dynamic coupling models, and incorporating region-specific adaptation mechanisms. In addition, interdisciplinary integration between history (archaeology) and climatology should also be further strengthened. These efforts will enhance the scientific robustness of human activity parameterizations and strengthen the capability of climate system models to simulate human-induced impacts. Together, they will support a deeper understanding of human-Earth system feedback mechanisms.</p>