The side-event at the Japan pavilion for the COP27Emission Reduction Paths in the Road Transport Sector
toward Carbon Neutrality −Concepts in the IPCC AR6−

November 12, 2022

The Pathways of Automobiles toward Carbon
Neutrality−Synergies and Trade-offs of SDGs
Keigo Akimoto, Ph.D, Prof.
Systems Analysis Group
Research Institute of Innovative Technology for the Earth (RITE)(Lead Author, Chapter 17, IPCC WG3 AR6)

Several opportunities to achieve CN

2Fig. SPM.5“The deployment of CDR to counterbalance hard-to-abate residual emissions is unavoidable
if net zero CO2 or GHG emissions are to be achieved.” (SPM C.11)
Even for achieving CN, large amounts of CDR deployment are estimated in many scenarios, anda certain amount of CO2 emissions in transport sector can be allowed and more economical.

Carbon neutrality options for automobile fuels
CO2 emissions

HEV etc.

ICE

Mainly
oil

PHEV

FCV/
H2 engine

BEV

In the caseof mix ofsyn. fuels

Syn.
fuels

Increase inratio ofsyn. fuels

Decrease in
offset ofemission

Offset ofemissions

3In the caseof mix ofsyn. fuels
Syn.
fuels

Electricity Electricity

Decreasein CO2
intensityofelectricity

Electricity

Decreasein CO2intensityofelectricity

HydrogenDecrease inCO2
intensity ofhydrogen

Decrease inoffset ofemission

Emission offset
by forestation
and CDR e.g.,
BECCS, DACCS There are several kinds of options for the carbon neutrality, and the BEV (+ zero CO2
intensity of electricity) is not the sole option.
 Higher cost-effective measures should be implemented, and this will also help reducepoverty and hunger basically.

Assumed scenarios for GHG emissions reductions
and technology improvements

4

The comprehensive and quantitative scenarios are estimated under different
outlooks of technologies and different emissions scenarios through atechnology-rich global energy systems model DNE21+.
Emission
reductions

Costs andpotentials ofVRE

B2.0C-0
B2.0C-0_ REN-EV

2 °C, >66%
(equal MAC)

Standard
Standard
Standard
Low cost of VRE Low cost of BEV Standard
and FCEV

B1.5C-0
B1.5C-0_ REN-EV

1.5 °C, >66%
(equal MAC)

Standard
Standard
Standard
Low cost of VRE Low cost of BEV Standardand FCEV

B1.5C-1
B1.5C-1_ REN
B1.5C-1_ REN-EV1.5 °C, >66%
(CN by 2050
in major
developedcountries)

Standard
Standard
Standard
Low cost of VRE Standard
Standard
Low cost of VRE Low cost of BEV Standardand FCEV

B1.5C-1_ REN-LimCDR

Prices ofCDR − biomass
passenger cars availability andDAC costs

Low cost of VRE Standard.

Limitation of CDR

Source: K. Akimoto et al., Assessments of road transportation sector considering comprehensive energy
systems toward carbon neutrality, Transportation Research Part D (2022).

RITE estimates using an IAM: Global sales ofnew cars under different scenarios

5 HEV and PHEV dominate the global sales of new passenger cars in all scenarios
except REN-EV. In the REN-EV scenarios, the share of BEV in the total number of new
car sales will reach around 90% in 2050。

RITE estimates using an IAM: Final energy consumption
for different countries under different scenarios
2015

2040

62050

 The cost-effective measures differ among countries, depending on the differences in
the implicit discount rate by income level, annual travel distance, secondary energy
prices, carbon prices to meet the emissions reductions.

Synergies and trade-offs of climate change mitigation

7“Accelerated and equitable climate action in mitigating, and adapting to, climate change impacts is
critical to sustainable development. Climate change actions can also result in some trade-offs. The
trade-offs of individual options could be managed through policy design.” (D.1)

Fig. SPM.8

In principle, these assessments were summarized from the underlying texts in the sectoral chapters including qualitative
assessments. There could be also other synergies or trade-offs. Also these synergies and trade-offs could be changed
depending on the intensity of the mitigation options (i.e. level of utilization of each technology).

Synergies and Trade-offs of SDGs in Transport

8Fig. SPM.8[Chapter 17]
 The mitigation options in the transportation sector are assessed as having synergies
with SDG 1 ‘no poverty’ and SDG 3 ‘good health and well-being’ due to reduced
environmental pollution, with exceptions in relation to pollution from biofuels and therisks of traffic accidents.
 Trade-offs are also mentioned in relation SDG 2 ‘zero hunger’ where the production ofbiofuels takes land away from food production.
 Synergies are assessed in relation to SDG 7 ‘affordable and clean energy’, SDG 8‘decent work and economic growth’ and SDG 9 ‘industry, innovation and infrastructure’.
 Some mitigation options, like the increased penetration of electric vehicles, requireinnovative business models, and digitalization and automatic vehicles will support thesocio-economic structures that impede adoption of EV’s and the urban structures thatenable reduced car dependence.

Synergies and Trade-offs of SDGs in Transport

9[Electric light duty vehicles => SDG3]- Synergies: BEVs have no tailpipe emissions, which further offsets theincreased PM emissions from road and tire wear. (Section 10.4.1)- Trade-offs: BEVs are generally heavier than their ICEV counterparts, which
may potentially cause higher stress on the road surfaces and tires, withconsequently higher PM emissions per kilometre driven. (Section 10.4.1)[Electric light duty vehicles => SDG12]- Synergies and trade-offs: Externalities from resource extraction are anotherconcern, though current volumes of lithium are much smaller than othermetals (steel, aluminium). (Section 10.3.2)[Biofuels => SDG3]- Synergies: Biofuels may also may offer a significant advantage in meeting
ambitious sulphur emission reduction targets set by the sectoralorganisations. (Section 10.3.1)[Biofuels => SDG14/15]- Synergies: Biofuels could be used in all segments of the transport sector, butthere may be some concerns about their feasibility. Specifically, there areconcerns about land use, water use, impacts on water quality andeutrophication, and biodiversity impacts.

Conclusions

10♦ Electrification is a key measure for achieving carbon neutrality. Shifts fromICE to EV are also important.

♦ On the other hand, CDR such as DACCS and BECCS will contribute tooffsetting the residual emissions of fossil fuels also in the transport sector.
In addition, synthetic fuels based on renewables will play a certain role toachieve carbon neutrality in transport sector.

♦ The assessments of total energy systems in energy supply, transport, andCDR are important for cost-effective emission reduction measures. BEVonly will not be a dominant measure in the road transport sector. Severalkinds of road transport measures have potential cost-effective reductions
in different time points, different countries, and different perspectives intechnologies.

♦ All of the options in the road transportation sector could have not onlysynergy effects on SDGs but also trade-off effects, depending on countries,
scales of deployments, different time points, etc.

♦ Lower costs of emissions reduction with consideration of full spectrum

options will be able to increase SDG1 (no poverty) and 2 (zero-hunger), forexample, while the IPCC AR6 had not assessed sufficiently, and therefore,
the balanced emissions reduction response measures toward carbon
neutrality will be important also in road transport sector.