Taiwan ranks 22nd worldwide in greenhouse gas emissions. One-third of these emissions come from the city of Kaohsiung, Taiwan. To mitigate global warming, the Taiwanese government and non-governmental organizations (NGOs) of environmental protection have promoted a series of energy conservation methods based on citizens’ pro-environmental behaviors. This research sorts these pro-environmental behaviors into five categories: diet, clothing, housing, transport, and recreation; further, it assesses them empirically by applying the theory of planned behavior (TPB) to a survey of 223 Kaohsiung residents. With the application of structural equation modeling, the indicators for each of these five models showed a good fit to the TPB, with goodness-of-fit (GFI) and adjusted goodness-of-fit (AGFI) values of 0.8 and above, comparative fit index (CFI) of 0.9 and above, and root mean square error of approximation (RMSEA) below 0.08. From these results, this research found that attitudes toward global warming influence citizens’ pro-environment behavioral intentions; in particular, perceived behavior control played an important role in the model. This research suggests that people will accept pro-environmental behaviors if they perceive evidence of the usefulness and convenience of these behaviors. “Keep it simple” might be a good byword for promoting energy conservation methods. Nevertheless, it seems that it will be hard to change citizens’ appetite or travel habits to mitigate global warming without providing clear, strong incentives.