Abstract: Based on the annual production data collected by Chinese Railway Statistic Center, the CO₂ emission of locomotives during 1975-2005 was calculated and the emission intensity and its dynamic characteristics were analyzed. The results show that the CO₂ emission of steam locomotives decreased while that of diesel locomotives increased with time because more diesel locomotives and electric locomotives were continually put into service to replace steam locomotives. The total CO₂ emission of locomotives in China's railway network decreased from 42.23 million t in 1975 to 16.40 million t in 2005. The emission intensity of CO₂ from two kinds of locomotives decreased at an average rate of 2.4 g/(converted t·km) per year. The proportion of the CO₂ emission of locomotives to the total emission in the sector of transportation, storage and post in China also persistently decreased from 1980 to 2005.

Key words: China's railways, energy consumption of locomotives, CO₂ emission