Mitigating life cycle GHG emissions of roads to be built through 2030: Case study of a Chinese province

Yuqiao Huang; Paul Wolfram; Reed Miller; Hessam Azarijafari; Fengdi Guo; Kangxin An; Jin Li; Edgar Hertwich; Jeremy Gregory; Can Wang

doi:10.1016/j.jenvman.2022.115512

Mitigating life cycle GHG emissions of roads to be built through 2030: Case study of a Chinese province

J Environ Manage. 2022 Oct 1:319:115512. doi: 10.1016/j.jenvman.2022.115512. Epub 2022 Jul 8.

Authors

Yuqiao Huang¹, Paul Wolfram², Reed Miller³, Hessam Azarijafari⁴, Fengdi Guo⁵, Kangxin An⁶, Jin Li⁶, Edgar Hertwich⁷, Jeremy Gregory⁸, Can Wang⁹

Affiliations

¹ State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), School of Environment, Tsinghua University, Beijing, 100084, China; Yale School of the Environment, Yale University, 195 Prospect St., New Haven, 06511, USA.
² Yale School of the Environment, Yale University, 195 Prospect St., New Haven, 06511, USA; Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park, MD, USA.
³ Yale School of the Environment, Yale University, 195 Prospect St., New Haven, 06511, USA.
⁴ Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; School for Environment and Sustainability, University of Michigan, Ann Arbor, 48109, USA.
⁵ Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
⁶ State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), School of Environment, Tsinghua University, Beijing, 100084, China.
⁷ Industrial Ecology Programme, Department of Energy and Process Engineering, Norwegian University of Science and Technology (NTNU), 7491, Trondheim, Norway.
⁸ Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; MIT Climate and Sustainability Consortium, Cambridge, MA, USA.
⁹ State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), School of Environment, Tsinghua University, Beijing, 100084, China; Tsinghua-Rio Tinto Joint Research Centre for Resources, Energy and Sustainable Development, Beijing, 1000084, China. Electronic address: canwang@tsinghua.edu.cn.

PMID: 35803068
DOI: 10.1016/j.jenvman.2022.115512

Abstract

The expansion of road networks in emerging economies such as China causes significant greenhouse gas (GHG) emissions. This development is conflicting with China's commitment to achieve carbon neutrality. Thus, there is a need to better understand life cycle emissions of road infrastructure and opportunities to mitigate these emissions. Existing impact studies of roads in developing countries do not address recycled materials, improved pavement maintenance, or pavement-vehicle interaction and electric vehicle (EV) adoption. Combining firsthand information from Chinese road construction engineers with publicly available data, this paper estimates a comprehensive account of GHG emissions of the road pavement network to be constructed in the next ten years in the Shandong province in Northern China. Further, we estimate the potential of GHG emission reductions achievable under three scenario sets: maintenance optimization, alternative pavement material replacement, and EV adoption. Results show that the life cycle GHG emissions of highways and Class 1-4 roads to be constructed in the next 10 years amount to 147 Mt CO2-eq. Considering the use phase in our model reveals that it is the dominant stage in terms of emissions, largely due to pavement-vehicle interaction. Vehicle electrification can only moderately mitigate these emissions. Other stages, such as materials production and road maintenance and rehabilitation, contribute substantially to GHG emissions as well, highlighting the importance of optimizing the management of these stages. Surprisingly, longer, not shorter maintenance intervals, yield significant emission reductions. Another counter-intuitive finding is that thicker and more material-intensive pavement surfaces cause lower emissions overall. Taken together, optimal maintenance and rehabilitation schedules, alternative material use, and vehicle electrification provide GHG reduction potentials of 11%, 4%-16% and 2%-6%, respectively.

MeSH terms

Animals
Carbon
China
Greenhouse Effect
Greenhouse Gases*
Life Cycle Stages
Recycling

Substances

Greenhouse Gases
Carbon