At present, research on relationships between carbon dioxide emissions and its influencing factors are concerned with linear causality relationships, and most literature has focused on the economic field to find its influencing factors. This article aims to investigate the causality relationships between carbon dioxide emissions and its influencing factors in China through the traditional Granger causality test and the Hiemstra and Jones test. The paper not only considers economic factors, but also takes social factors into consideration. It has been concluded that linear Granger causality relationships exist from CO₂ emissions to GDP, gross national income, and freight traffic volume. Compared with linear relationships, unidirectional nonlinear Granger causality relationships run from CO₂ emissions to resident consumption levels, and also from the urban population to CO₂ emissions. Moreover, there are bidirectional nonlinear causality relationships between CO₂ emissions and GDP, and between CO₂ emissions and the possession of private automobiles. Finally, based on the above conclusions, this article analyzes energy-saving and emission reduction measures as proposed by the Chinese government, and puts forward policy recommendations to reduce carbon dioxide emissions.