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Page 8 of 18 Tong et al. Carbon Footprints 2025;4:2 https://dx.doi.org/10.20517/cf.2024.44

Table 1. Scenario setting
Change in
Scenarios energy Change in direct input coefficient Change in final
demand
structure
Baseline (2030) Renewable Unchanged 1. The final consumption
energy growing with an annual
accounts for growth rate of 2%
25% 2. The capital formation
growing with an annual
growth rate of 5.89%
3. The export growing
with an annual growth
rate of 5.60%
S1: Low-carbon Renewable Unchanged Id
transition of energy rises to
energy structure 70%
S2: Closed-loop Id Given the increasing rate of recycling materials used in automobile Id
recycling of manufacturing, the intermediate input value for the “ferrous metal smelting and
materials rolling processing industry” and the “plastic product industry” consumed by the
automobile manufacturing industry is reduced, and a new intermediate flow
matrix and direct consumption coefficient matrix are generated
S3: Sharing Id Id All three final demands
mobility reduced by 13% to 57%
transition on the basis of the annual
growth rate

Scenario 1: low-carbon energy transition
The low-carbon transition of the energy structure scenario serves as a reference standard for the three types
of emission reduction scenarios, reflecting the overall impact of energy structure optimization and
transformation on GHG emission reduction. Specifically, it reflects the impact of a decrease in the
proportion of fossil fuels in primary energy consumption and an increase in the proportion of non-fossil
fuels.

The “Frontier Report on China’s Energy Development (2021)” predicts that under the “ The goals of carbon
peaking and carbon neutrality scenario, the share of fossil fuel consumption in China will decrease to
[52]
around 31% by 2060 . Based on this, this paper sets the share of non-fossil fuels in primary energy
consumption in the low-carbon energy transition scenario at 70% and adjusts the emission intensity across
various industrial sectors. Other parameters remain consistent with the baseline scenario.

Scenario 2: closed-loop recycling of materials scenario
The material closed-loop reuse scenario reflects the impact of closed-loop recycling of key automotive raw
materials, where discarded materials are used to produce new products of the same type, on GHG emission
reduction.

Currently, the construction of a closed-loop supply chain in China’s automobile manufacturing industry is
in its initial stages, with production primarily using virgin materials. This paper takes steel and plastic as
examples. Due to the complexity of non-ferrous metals as a major material consumed in automobile
manufacturing and the uncertainty in their usage affected by the transition to new energy vehicles, they are
not discussed here. For steel, currently, only 8% of recycled steel meets the quality standards for reuse in
automobiles, but with appropriate dismantling processes and intelligent scrap steel recovery and processing
flows, it is estimated that 85% of the steel demand in automobile production could be met through recycled
[53]
steel . For plastics, existing research on dynamic material flow analysis of passenger vehicle plastics in
China shows that from 1950 to 2018, only 28% of automotive scrap plastics were recycled, with only half of
[54]
these (14%) being reused within the industry through component reuse . With improvement in