Abstract:

Carbon Generalized System of Preferences (carbon GSP) is one kind of Voluntary GHG Emission Reduction Mechanisms, which take residents as the main objects. It is an important exploration for taking subway travel as a low-carbon behavior into carbon GSP to build a low carbon society. This paper proposes two different carbon emission reduction calculation methods of subway travel, based on CCER methodology “Mass Rapid Transit Projects”, combined with the availability of traffic data and the purpose of carbon GSP. Carbon emission reductions of Guangzhou subway travel in 2015, as an example, were calculated by using these two methods. Under substitution method, the carbon emission reductions of Guangzhou subway travel were about 0.5419 kg CO₂ per person, but under averaging method, this value was about 0.5155 kg CO₂ per person. According to the passenger traffic of Guangzhou subway in 2015, the annual carbon emission reductions of Guangzhou subway system were about 1.30 million t CO₂ under substitution method and 1.24 million t CO₂ under averaging method, respectively. In these two methods, substitution method is designed based on the existing CCER methodology, which has theoretical basis. But in the actual calculation process, the setting of alternative travel patterns will greatly rely on the subjectivity of survey objects. In contrast, the baseline of averaging method is the current urban motorized travel patterns, less subjected to human disturbance. By contrast, the averaging method is more suitable for calculating subway travel carbon emission reductions of carbon GSP.

Key words: carbon GSP, subway, substitution method, averaging method, emission reductions