Coupling model of human-earth system to explore global climate and carbon emission changes

Against the backdrop of global climate change, Earth System Models (ESM) are widely used in the projection of future climate change. With the continuous development and evolution of Earth System Models, in addition to the inherent errors of the models themselves, the dynamic changes in future human activities also bring extremely significant uncertainties to the projection of climate change. At a time when the impact of human activities on climate change is continuously intensifying, Integrated Assessment Models are being more and more widely applied in the projection of future human social development.

In view of this, we set about coupling the two types of models, Earth System Models and Integrated Assessment Models, to explore the changing trends of future human society and the climate system. Specifically, first, we use an optimized climate change loss function to make the output results of the Integrated Assessment Model more reliable. As a result, the obtained future global CO₂ emission data can also better fit the actual development situation of future human society. Secondly, new carbon dioxide emission data is used to drive the Community Earth System Model (CESM). Finally, the experimental results after coupling the Earth System Model and the Integrated Assessment Model are compared with the CMIP6 simulation experimental results to further explore the future climate change in 12 global regions after comprehensively considering human activities. The research results clearly show that the high-value areas of future climate change losses are concentrated in India and Southeast Asia. Moreover, extreme high-temperature and extreme precipitation events in the regions near the equator will increase significantly in the future.

This research not only helps to conduct scientific and rigorous assessments of regional climate change losses and accurately predict future CO₂ emission paths, but also greatly enriches the content related to the impact of human activities in Earth System Models and has extremely important promoting significance for the scientific assessment of future climate change.