Abstract: Based on the PET (Population, Environment and Technology) model, this paper establishes an analytical framework for the equilibrium of the three sections, i.e., production, consumption and government. On this basis, it makes use of China's population, economy and carbon emission data from 1995 to 2016 to carry out the biased estimation of ridge regression. The findings show that economic factors are still the main cause of carbon emission growth in China, but factors of population and consumption, especially the relationship between aging and carbon emission, are becoming positively related increasingly; the impact of energy consumption on carbon emissions is increasingly obvious. China's energy conservation and emission reduction should not only start from traditional economic factors to reduce energy consumption per unit of GDP, but also pay attention to the balanced development of population size, population growth and population structure, improve the quality of the population, strengthen the technological innovations, advocate the consumption concept of energy conservation and environmental protection, and effectively transform the mode of economic growth.

Key words: PET model, carbon emission, ridge regression estimation, aging population, energy conservation and emission reduction