Estimation of Greenhouse Gas Emissions from Road in China: A Province-Level and Hierarchical Analysis

Road infrastructure plays a vital role in the transport sector greenhouse gas emissions. Estimation of greenhouse gas emissions from road infrastructure in China is a comprehensive reflection of social equity and sustainable development in many provinces. It has a significant impact on the total GHG emissions in China and the change of regional GHG emissions pattern in the future. In this study, the emission characteristics and evolution trends of road infrastructure in China from 2009 to 2019 is discussed base on the life cycle estimation method. The result shows that GHG emissions from road infrastructure construction had a downward trend since 2009, which may be the result of the implementation of low-carbon policies by the Chinese government in 2009. Class-IV road has become the leading factor affecting the amount of GHG emissions from national road infrastructure construction, indicating that class-IV road construction has a great potential for emission reduction, such as improving its construction technology, etc. At the same time, the amount of GHG emitted by all levels of roads continues to rise, which has increased by 2.8 times in 2019 compared to the number in 2009. This could be explained by the increasing road mileage and economy in China. The GHG emissions of expressway operation are the highest and growing fastest in all kinds of roads, revealing that expressways’ operation and maintenance should become the key link of traffic emission reduction. Effective measures should be taken to improve the maintenance frequency. Finally, it is found that the marginal cost of emission reduction is higher in the developed regions, while the cost of emission reduction is lower in the less developed regions. This may be explained that different regions have different potential and difficulty of emission reduction due to the differences of resources, production advantages and economic development between them. Therefore, it is necessary to build a national carbon market. It is proved that this can ensure that regions with weak economic capacity or fragile ecology can obtain additional net benefits through carbon trading. The results of this study provide data and theoretical support for decision makers to formulate emission reduction policies in different regions and ultimately help improve the whole performance of GHG emissions from road infrastructure construction.