sRunsen Zhang
Civil and Environmental Engineering/Architecture Unit, IDEC
Hiroshima University, Japanrzhang@hiroshima-u.ac.jp

SUMMARY
To create a better understanding of whether and how transport electrification would contribution to climate change mitigation, this researchaims to develop an integrated modeling methodology to couple transport model, economic model, and climate model, which can depict
the interaction between the transport, energy, macroeconomy, and climate change. Scenarios are created to simulate the potential for different
transport, energy, and climate policy interventions. This project attempts to develop an interdisciplinary framework that integrates
transport planning and climate change studies, with the objective of helping shape the policy agenda for electrified transport.

INTRODUCTIONRESULTS Background Emission from transport

The transport sector accounts for approximately a quarter of global greenhouse gasemissions. Road transport is by far the biggest emitter accounting for more than half ofall transport-related emissions. Switching to electrified road transport permits an
optimistic outlook to meet the stringent climate targets. Electric vehicles (EVs) areoften considered as an attractive solution towards a green future.

 Objectives
Are EVs as green as they are supposed to be?
To understand the role of transport electrification in achieving climate change targets,
this study is intended to (1) reveal the interactive mechanism between transport
electrification, energy, and climate change, and (2) provide a better policy
simulation tool for the electrification of road transportation towards a green future.

Figure 2. Emission from transport

 Emission by sectors
 Although transport electrification has more
powerful and effective impacts on emission
reduction for transport sector, it requires highemissions in energy supply sector if thetransport is not powered by decarbonizedelectricity generation.
 Compared with the high preference on
renewable energy, carbon pricing has the mosteffective effects on emission reduction.

METHODOLOGYTransportmodel••••••

GDP, Population
Industrial value added
Energy and carbon
price•••

Transport demand
EnergyCapital cost

Figure 3. Emission by sectors•••

Transport demand
Energy consumption
Emissions

Climatemodel

Economic
model

Energy supply sector
End-use sector
Macroeconomicsystem•••

GHG emissions
Radiative forcingGlobal mean
temperature changes

Figure 1. Model framework
 The transport model
The transport model offers spatially flexible and temporally dynamic simulationsof transport demand, energy use, and emissions. To understand how transport
electrification might affect the anticipated low carbon transition, the transport model
considers more technological details and behavioral factors on EVs.
 Coupling of transport model, economic model, and climate model
Computable General Equilibrium (CGE) model and simplified climate model
MAGICC are employed to couple with the transport model. An iterative algorithm
is used to obtain the convergence of coupled transport-economic-climate model.
The CGE model passes the macroeconomic variables to transport model fortransport demand projection. The transport demand, transport-related energy
consumption, and capital cost for transport device feedback from transport model ispassed to economic model. This loop continues until the energy consumptions
computed in economic model and transport model are equal.

 Emission from power sector
 Transport electrification slightly produces
more emissions from energy supply, because
the deployment of EVs requires more
electricity.
 Carbon pricing has the most powerful effecton emission reduction in power sector,
followed by high preference on renewableenergy.
 Transport electrification needs to beimplemented together with decarbonization ofpower sector, otherwise the emissions frompower sector still keep growing.
Figure 4. Emission from power sector

 Biofuel EV policy produces lower consumption ofbiomass compared with scenarios without the
deployment of EV.
 Carbon pricing tends to increase theconsumption of biomass in all sectors
including transport sector.

 Scenario definition
Table 1. Scenarios frameworkSCENARIOS

EV
deployment

LoEV_BaU
LoEV_2DCarbon
pricing

LoEV_Renew
HiEV_BaU

Renewableenergy

HiEV_2D
HiEV_Renew

 For transport sector, the deployment of EVs ismore effective to reduce the emissions thancarbon pricing.
 Electrified road transport together with carbon
pricing have the highest mitigation potential.
 Renewable energy policy does not have direct
positive effects on emission reduction intransport sector.

DESCRIPTION
Moderate preference on EVs with noclimate efforts
Moderate preference on EVs with nocarbon pricing for 2 degree target
Moderate preference on EVs with highpreference on renewable energy
100% of EV market share by 2050 with noclimate efforts
100% of EV market share by 2050 withcarbon pricing for 2 degree target
100% of EV market share by 2050 withhigh preference on renewable energy

Figure 5. Biofuel consumption

DISCUSSION & IMPLICATIONS
 Transport electrification is bound to shift the emissions from transport sector topower sector.
 EV policy fails to contribute to the emission reduction when the power sector is notdecarbonized, though the transport-related emissions can be reduced significantly.
 Transport electrification might help to ease the pressure of biofuel consumption on
agricultural production and food security.
 Single transport electrification does not mean the successful emission reduction.
Instead, the linkage between sectors deserve attention to meet the stringent climate
target.
 Renewable energy policy and carbon price need to be taken into consideration tomatch up with the transport electrification policy.