November 15, 2017
Turkish Pavilion COP23, Bonn

Sustainable Climate Change Response
Measures under the Paris Agreement
Bianka Shoai-Tehrani
Keigo Akimoto
Systems Analysis Group
Research Institute of Innovative Technology for the Earth (RITE)

Reviews of emission reduction efforts of NDCs(Nationally Determined Contributions)for sustainable climate change response measures

How to measure the comparability of efforts
The submitted NDCs include the targets of emissions reduction from different
base years, CO2 intensity, and CO2 emission reductions from baseline (w/w.o.
clear definition of baseline). We need to interpret them through comparable
metrics to measure the efforts:
 Simple metrics (easily measurable and replicable)- Emissions reduction ratios from the same base yearetc.

 Advanced metrics (more comprehensive, but require forecasts)- Emission reduction ratios from baseline emissions- Emissions per unit of GDP

etc.

 More advanced metrics (most comprehensive, but require modeling)- Energy price impacts- Marginal abatement cost (per ton of CO2)
- Abatement costs as a share of GDP

etc.

3

2030 Emission Target of Japan’s NDC

4After the Great East Japan Earthquake and the Fukushima nuclear power accident, in 2014 theJapanese Government decided a new strategic energy plan aiming at a better balance of S+3E
(safety, energy security, economy, and environment) and at reducing dependency on nuclear
power plants. The energy mix for 2030 was decided based on the strategic energy plan, andfollowing the energy mix, the Japan’s NDC was decided in 2015.
2030; Compared to 2013（compared to 2005）
Energy-related CO2-21.9% （-20.9%）

Other GHGs

-1.5% （-1.8%）

Reduction by absorption-2.6% （-2.6%）

Total GHGs

-26.0% （-25.4%）
Energy-related CO2 by sector

Unit: Mt-CO2

2005

2013

2030

Industry

457

429

401

Commercial and other

239

279

168

Residential

180

201

122

Transport

240

225

163

Energy conversion

104

101

73

1219

1235

927

Energy-related CO2 Total

Japan’s energy mix in 2030 – Electricity mix –5- The government intends toreduce the dependence on
nuclear power as compared withthat before the accident. However,
the government had to also takethe 3E: energy security, economic
efficiency, environment into
account, and consequently theshare of nuclear power is decided
to be 20-22% of total electricity in
2030.
- We believe that this maintains agood balance of electricity mix inJapan. On the other hand, it is noteasy to achieve the electricity
saving target given historical
trends and the nuclear powershare target from the current
restarting conditions of nuclear
plants.
The Japanese government, July 2015

Emissions reduction ratio from base year
for Japan and other major countries

6

Emissions reduction ratio from base year
Japan：in 2030, -26% from 2013
levels
US： in 2025, about -26 to-28% from 2005 levels
EU28： in 2030, -40% from 1990
levelsRussia： in 2030, -25% to-30% from 1990 levels
China： in 2030, CO2 intensity of 60% to -65% from 2005 levels

From 1990

From 2005

From 2013-18.0%-25.4%-26.0%-14 to -16%

-26 to -28%

-18 to -21%

-40%

-35%

-24%

-25 to -30%

+10 to +18%

ー+379 to +329%+129 to +105%

ー

Underlined: official NDCs, Others: estimated by RITE

The reduction ratios can vary significantly according to the adopted base year. If we take 2013 as the baseyear, Japan’s target looks more ambitious in the emissions reduction ratio than the US’s or the EU’s.

GHG intensity of GDP (MER)

Note) For countries submitting their NDCs with ranges, the lower range of emission targets is shown.
Source) estimated by RITE

Even from the GHG intensity, Japan’s NDC sets a more demanding target than the US and the EU.

7

CO2 marginal abatement costs
8

Average of 2025-2030

2030 (2025 for the U.S.)【World GDP loss due to mitigation】 NDCs:0.38%; the global least cost：0.06%
The least cost (equal marginal abatement costs)：6$/tCO2
Switzerland

380

Japan

378

EU28

210

Canada

166

Korea

144

New Zealand95

United States

85

Norway70

East Europe (Non-EU member)

58

Thailand54

Australia

33

Mexico27

Kazakhstan

14

Belarus12

Russia4South Africa

1

Turkey

0

India

0

Ukraine

0

China

0

0

50

100

150

200

250

300

CO2 marginal abatement cost ($/tCO2)

Source: J. Aldy et al., Nature Climate Change, 2016-

Source: K. Akimoto et al., Evol. Inst. Econ. Rev., 2016

Emission reduction costs are an important indicator for measuring emission reduction efforts.
The estimated marginal abatement costs of NDCs are largely different among countries.
The difference will induce carbon leakages, and the leakages will reduce the effectiveness of global emission
reductions.

350

400

CO2 marginal abatement cost for the U.S, EU and Japanconsidering several kinds of policy constraints
CO2 marginal abatement cost ($/CO2)

500

400

II-c
I-d

III-d
III-c

- It is not easy to achieve the least costmeasures because there are several
kinds of social and political constraints
in each nation.

III-b- The mitigation costs constrained byother policies can be much higher thanthose under the least cost measures.

I-c

300
II-b
II-a

200

III-a

100

9

I-b
I-a

0

I. US
I-a: -26%; the least costI-b: -28%; the least cost
I-c: -26%; power sector
according to CPP
I-d: -28%; power sector
according to CPP* CPP: Clean Power Plan

Source: estimated by RITE DNE21+

II. EU
II-a: the least costII-b: Brexit (-40% for UK)
II-c: splitting into ETS andnon-ETS sectors

III. Japan
III-a: the least cost undernuclear of maximum 20%
III-b: the least cost undernuclear of maximum 15%
III-c: following the NDC
including the energy mix(nuclear of 20%)
III-d: following the NDC
including the energy mix
but nuclear of 15%

Long-term target
for sustainable climate change response measures- considering uncertainties and role of innovation -Global CO2 emission profiles toward 2300 for the 2 °C targets
11

50
Business as Usual (BaU)(the middle socioeconomic scenario)

CO2 emissionis [GtCO2/yr]

40

Submitted NDCs

30
+2℃ stabilization under climate
sensitivity of 2.5℃ (Noexceedance of 580 ppm)

20

+2℃ stabilization under climate
sensitivity of 3.0℃ (Noexceedance of 500 ppm)
450 ppm CO2eq stabilization

10

0

-10
2010

2050
2060

2100
2110

2300
2160

2210

2260

Submitted NDCs
Estimated by RITE using
MAGICC and DNE21+- The global CO2 emissions should be nearly zero for a long-term period in the far future in any pathway toachieve temperature stabilization.
- On the other hand, the allowable global CO2 emissions toward the middle of this century have a wide
range according to the uncertainties in climate sensitivity (or achieving probability) even when thetemperature target level is determined as a 2 °C. We should use this flexibility to develop several kinds ofinnovative technologies and societies.

Marginal CO2 abatement costs (Carbon prices) for the 2 °C target
12

SSP: “Shared Socioeconomic Pathways”

SSP2 (Middle of the Road)+2°C stab. underclimatesensitivity of
2.5°C+2°C stab. underclimate sensitivityof 3.0°C

2050

12

135

2100

408

427

SSP1 (Sustainability)

450 ppm CO2eq
stab. (climate
sensitivity of
3.4°C)+2°C stab. underclimatesensitivity of
2.5°C+2°C stab. underclimatesensitivity of
3.0°C

450 ppm CO2eq
stab. (climate
sensitivity of
3.4°C)

604

14

117

518

457

134

140

143

Unit: $/tCO2 (real price); Uniform carbon prices among all nations are assumed.
Source) estimated by RITE DNE21+- The marginal abatement costs (carbon prices) for the 2 °C target are huge even under the global least costmeasures (uniform carbon prices) except in the case of low climate sensitivity (2.5 °C) and by 2050.
- The carbon price in SSP1 that energy demands in the end-use sectors are much smaller than in SSP2 ismuch lower than that in SSP2.
- Technological and social innovations are definitely required for the 2 °C target to be achieved in harmony
with other SDGs. (Newly emerging technologies such as AI, IoT etc. will induce social changes which may
lower the energy demand.)Global primary energy supply
13
30000

Total primary energy supply（Mtoe/yr）

2050

2100

Coal w.o. CCS
Coal with CCS

25000

Oil w.o. CCS
20000

Oil with CCS
Natural Gas w.o. CCS

15000

Natural Gas with CCS
Biomass w.o. CCS

10000

Biomass with CCS
5000

Hydro and Geothermal
Nuclear power

0
SSP1

SSP2

Business as Usual
(BaU)

2010

SSP1

SSP2

SSP1

SSP2

+2℃ stabilization 450 ppm CO2 eq
stabilization
under climate
sensitivity of 2.5℃
(No exceedance of
580 ppm)
2050

Source) estimated by RITE DNE21+

SSP1

SSP2

Business as Usual
(BaU)

SSP1

SSP2

SSP1

SSP2

+2℃ stabilization 450 ppm CO2 eq
stabilization
under climate
sensitivity of 2.5℃
(No exceedance of
580 ppm)

Wind power
Photovoltaics

2100

SSP (Shared Socioeconomic Pathways)
SSP1: Sustainability
SSP2: Middle of the Road

- The energy supply isvery different in 2050
according to theuncertainty in the
climate sensitivity anddifferent socioeconomic
scenarios.
- The total amount ofenergy supply in the
SSP1 world is muchsmaller than that in the
SSP2 world.
- But in any scenarios
for the 2 °C target as
the IPCC also showed, alarge amount of BECCS
is employed by 2100.
This is technologicallyfeasible, but will be very
difficult to be achievedin the real world.

Harmonization among climate change issues and other SDGs needed- We have multiple agendas to tackle. Harmonization among climate change issues and other SDGs isnecessary.

14

Image of standard scenario by models and real world scenarios
for deep cuts
Model world:
Ordinary technology progress
Carbonprice

Carbon price/
Marginal abatement cost

Realistic world requirement:
Innovations stimulated & implemented
Carbonprice

Baseline scenario
CO2emission

Implicit carbon price/
Marginal abatement cost

Baseline
scenario
CO2emissionIntervention scenario

15

By technology andsocial innovations
Intervention scenario

Explicit high carbon prices such as over 100$/tCO2 in real price are unlikely in a real world. Technology
and social innovations resulting in low (implicit or explicit) carbon prices (including coordination of
secondary energy prices) are key for deep emission cuts to be implemented.

5th Science and Technology Basic Plan of Japan- “Society 5.0” (“Super Smart Society”) -16

Source) Japanese Government

Source) Gendai Business ”http://gendai.ismedia.jp/articles/-/50859”

AI + IoT + big data + ….
Operation ratio of automobiles is about
4%, for example. There is largely roomfor energy efficiency improvement by
sharing economy.

- Wide range of innovations of technologies and theirintegrations are required for improving our welfare
and sustainable development.
- AI, IoT, big data etc. will be able to stimulate suchinnovations.

Conclusions♦ Measuring the ‘emission reduction efforts (degree of ambition)’ of NDCs is key for

effective emission reductions under the Paris Agreement.
♦ Measuring the efforts is a hard work but can be approached by employing multiple
good indicators including the mitigation costs.
♦ Large differences in marginal abatement costs will hinder the sustainable measures by
all nations, and the coordination of the NDCs through the review process will be
important.
♦ Evaluations of the mitigation costs require comprehensive models and include
uncertainties but using several models helps ensure comparability to some extent.
♦ A challenging issue on evaluations of the mitigation costs is what constraints areinevitable and should be considered in estimating the mitigation costs. Several socialand political conditions hindering the least cost mitigation measures exist in eachnation. Cheaper emission reduction measures should be pursued, but some of therealistic constraints should also be considered.
♦ The estimated mitigation costs for the 2 °C goals are large even under the assumptionsof the least cost measures. For the sustainable measures by all nations pursuing the 2°C goal, broad innovations harmonized with SDGs are necessary.

17Appendix

Huge costs are estimated for achieving the 2 °C target
19

Corresponding to 2 °C target

Source) IPCC WG3 AR5Corresponding to 2 °C target- According to the IPCC AR5, the CO2 marginal abatement costs(carbon prices) for the 430-530 ppm CO2eq (which areconsistent with the 2 °C target) are about 1000-3000 $/tCO2 (2575 percentile) and 150-8000 $/tCO2 (full range) in 2100.
- About 25% of the analyzed scenarios estimate global GDP
losses of over 10%.
- The feasibility of such scenarios should be carefully examinedin terms of various real world constraints.

Global emissions by sector for the 450 ppm pathways
20

Source) IPCC WG3 AR5- The IPCC 450 scenario assumes large amounts of bioenergy with CCS and negativeemissions in power sector, or large amounts of afforestation. While BECCS andafforestation are important measures to reduce CO2 emissions , such scenarios are
unrealistic in the real world.

Energy Assessment Model: DNE21+

21♦ Linear programming model (minimizing world energy system cost)♦ Evaluation time period: 2000-2100
Representative time points: 2000, 2005, 2010, 2015, 2020, 2025, 2030, 2040, 2050,
2070, 2100

♦ World divided into 54 regions
Large area countries are further divided into 3-8 regions, and the world is divided
into 77 regions.

♦ Bottom-up modeling for technologies both in energy supply and demandsides (about 300 specific technologies are modeled.)♦ Primary energy: coal, oil, natural gas, hydro&geothermal, wind,photovoltaics, biomass and nuclear power♦ Electricity demand and supply are formulated for 4 time periods:
instantaneous peak, peak, intermediate and off-peak periods♦ Interregional trade: coal, crude oil, natural gas, syn. oil, ethanol,hydrogen, electricity and CO2♦ Existing facility vintages are explicitly modeled.
- The model has regional and technological information detailed enough to analyze sectoral
measures. Consistent analyses among regions and sectors can be conducted.

Region divisions of DNE21+

22

Technology Descriptions in DNE21+ (1/2)
23

Industry

Fossil fuels
Coal
Oil (conventional, unconv.)
Gas (conventional, unconv.)

Energy conv.
processes(oil refinery, coalgasification, bioethanol, gas
reforming, waterelectrolysis etc.)

Unit
production
cost

Iron & steel
CementPaper & pulp
Chemical (ethylene, propylene,ammonia)

Aluminum
Cumulative production

Solid, liquid and gaseous fuels, andelectricity <Top-down modeling>

Renewable energies
Hydro power & geothermalWind power
Photovoltaics
Biomass

ElectricPower
generation

Unit
supplycost

Transport
vehicleSolid, liquid and gaseous fuels, andelectricity <Top-down modeling>

Residential & commercial
Annual production

Nuclear power

CCS

Refrigerator, TV, air conditioner
etc.
Solid, liquid and gaseous fuels, andelectricity <Top-down modeling>Technology Descriptions in DNE21+ (2/2)–An Example for High Energy Efficiency Process in Iron & Steel Sector–24
Blast furnace, sintering
furnace, BF, BOF,
casting, and hot rolling

Coal forsteel sector

24.1
GJ

Type III:
Current coke oven23.8 GJ

Recycling ofwaste plastics
and tires
0.25 GJ

Waste plastics
and tires
0.25 GJ

22.5 GJ

Type IV:
Next-generation
coke oven

Electricity (grid)Power
generation
facility

Electricity
455 kWhType III and IV:
High-eff.
Intersection(Sophisticatedsteelmaking
process with manyenergy saving
facilities including
CDQ, TRT, COG
and LDG
recovery)(Larger scalecapacity plant)

91 kWh111 kWh

Carbon capture
from BFG

Compressed
CO20.60 tCO2

0.98 GJ

Utility
4.1 GJ

Heavy
oil

Process gases recovery
8.6 GJ

Steel product derived
from BOF steel
1 ton of crude steel
equivalent for each type

BF: blast furnace, BOF: basic oxygen furnace, CDQ: Coke dry quenching,
TRT: top-pressure recovery turbine, COG: coke oven gas, LDG: oxygen furnace gas

History of climate sensitivity judgment by IPCC and thesensitivity employed in the scenario assessments of the
IPCC WG3 AR525

Equilibrium climate sensitivity
Likely range (“best estimate” or “mostlikely value”)

Before IPCC WG1 AR4Same “likely” range
1.5−4.5°C (2.5°C)

IPCC WG1 AR4

2.0−4.5°C (3.0°C)

IPCC WG1 AR5

1.5−4.5°C (no consensus)

Global mean temperature estimations for the long-term
scenarios in the IPCC WG3 AR5 (employing MAGICC)

2.0ｰ4.5°C（3.0°C）[Based on the AR4][The related descriptions of the SPM of WG1 AR5]

Likely in the range 1.5 °C to 4.5 °C (high confidence)
Extremely unlikely less than 1 °C (high confidence)
Very unlikely greater than 6 °C (medium confidence)
No best estimate for equilibrium climate sensitivity can now be given because of a lack of agreement on values across assessed lines ofevidence and studies.

♦ The equilibrium climate sensitivity, which corresponds to global mean temperature increase inequilibrium when GHG concentration doubles, is still greatly uncertain.
♦ AR5 WG1 judged the likely range of climate sensitivity to be 1.5−4.5 °C, in which the bottom range
was changed to a smaller number than that in the AR4, based not only on CMIP5 (AOGCM) results but
also other study results.
♦ AR5 WG3 adopted the climate sensitivity of AR4, which has the likely range of 2.0−4.5 °C with the best
estimate of 3.0 °C, for temperature rise estimates of long-term emission scenarios.

Assumed temperature trajectories for the 2 °C target

26

There are several uncertainties concerning theachievement timing and probability for the 2 °C target
Estimated by RITE using MAGICC

Global mean temperature change
relative to 1850-1899 [K]2.5+2℃ stabilization under climate
sensitivity of 2.5℃ (Noexceedance of 580 ppm)

2

1.5
+2℃ stabilization under climate
sensitivity of 3.0℃ (Noexceedance of 500 ppm)

1

0.5
2050

0
2010

2060

450 ppm CO2 eq stabilization(climate sensitivity of 3.0℃)

2100
2110

2300
2160

2210

2260

The climate sensitivity assumes:
3.0 °C: according to the WG1 AR4 judgment, and
2.5 °C: according to the judgment before AR4 (the likely range is as same as the WG1 AR5)

Global GHG emission profiles toward 2100
for the 2 °C target
70

Business as Usual (BaU)

GHG emissions [GtCO2eq/yr]

60

Submitted NDCs

+14%

50

+2℃ stabilization underclimate sensitivity of 2.5℃
(No exceedance of 580 ppm)
+2℃ stabilization underclimate sensitivity of 3.0℃
(No exceedance of 500 ppm)
450 ppm CO2eq stabilization

40
-42%

30
20

-74%

Historical

10
Submitted NDCs

0
1990

27

2010

2030

2050

2070

2090

2100

Estimated by RITE using MAGICC, DNE21+ and non-CO2 GHG models- The corresponding GHG emission trajectories for the 2 °C target vary widely
particularly in 2050.
- There are large gaps between the expected emissions under the submitted NDCs andthe 450 ppm CO2eq pathway.

Global electricity generation

28

1200002050

2100

Coal w.o. CCS

Electricity Generation （TWh/yr）

Coal with CCS
100000Oil w.o. CCS
Oil with CCS

80000

Natural Gas w.o. CCS
Natural Gas with CCS
Biomass w.o. CCS

60000

Biomass with CCS
Hydro and Geothermal

40000

Nuclear power
Wind power

20000

Photovoltaics
Hydrogen
0
SSP1

SSP2

Business as Usual
(BaU)

2010

SSP1

SSP2

+2℃ stabilization
under climate
sensitivity of 2.5℃
(No exceedance of
580 ppm)
2050

SSP1

SSP2

450 ppm CO2 eq
stabilization

SSP1

SSP2

Business as Usual
(BaU)

SSP1

SSP2

+2℃ stabilization
under climate
sensitivity of 2.5℃
(No exceedance of
580 ppm)

SSP1

SSP2

450 ppm CO2 eq
stabilization

2100

Source) estimated by RITE DNE21+- CO2 emissions from power sector in most of the scenarios for the 2 °C target are nearly zero.
- The total amounts of electricity for the 2 °C target will increase with deeper emission reductions due tosubstitution for fossil fuel use in other sectors.

Global final energy consumption
2050

25000

29

2100

Final Energy Consumption (Mtoe/yr)

Coal
20000

Biomass
Oil

15000

Bio-fuel
10000

Natural Gas
Hydrogen

5000

Electricity
0
SSP1

2010

SSP2

SSP1

SSP2

SSP1

SSP2

SSP1

SSP2

SSP1

SSP2

SSP1

SSP2

Business as Usual +2℃ stabilization 450 ppm CO2 eq(BaU)stabilization
under climate
sensitivity of 2.5℃
(No exceedance of
580 ppm)

Business as Usual +2℃ stabilization 450 ppm CO2 eq(BaU)stabilization
under climate
sensitivity of 2.5℃
(No exceedance of
580 ppm)

2050

2100

Source) estimated by RITE DNE21+

Outlook of steel productions(primary and secondary productions)

Old scrap based
production

2000

Total crude steel
production

SSP2

Source: estimated by RITE

SSP1

1500

SSP2

?

SSP1

1000
Iron ore based
production
500

?

0
1990

2000

Crude steel production(Mt/yr)

2500
2000
1500
1000
500
0
1990

2010

2020

2030

2040

2050

2060

2070

2080

The production reductions after 2100 will
help to mitigate requirements of negativeemission
2090
2100 measures and to achieve the net
zero emission more easily than that by 2100.

SSP1

2500
Low income

Lower middle income

Total crude steel
production by region

Upper middle income
High income

2100

Crude steel production(Mt/yr)Crude steel production (Mt/yr)

Scenario

Statistics

2500

30

2000
1500
1000
500
0
1990

SSP2
Low income
Lower middle income
Upper middle income
High income

2100

Importance of product innovation
31

CO2 emission (index)
Waste, recycle
Maintenance

Emission
reduction effects:
about -45%

MovingAutomobile production
Material production

The emissions in the production
processes increase slightly, but thosein the stage of use decrease greatly.

Emission reduction potentials by devices,high energy efficiency appliances

Gasoline
2.0L ICE

Prius
2009

Emission reduction potentials inwhole sectors by IT solutions

Prius
2015

Source) Toyota

Global potentials:
About 4.27-4.41 GtCO2

Power generations
Appliances

IT products

Japan’s contributions

Global potentials:
About 3.7-7.9 GtCO2

Industry

Commercial Residential

Transportation
Energy conv.

Marginal abatement costs estimations across models(RITE DNE21+, FEEM WITCH and NIES AIM)
Only energy-related CO2
emission reductions in 2030

250
200
The average between 2025 and 2030 for GHG emission recutions
150
100

USG Social Cost of
Carbon (SCC):
53$/tCO2 for 2025-30

50

U.S.

EU

China

India

WITCH

DNE21+WITCH

DNE21+WITCH

DNE21+WITCH

DNE21+

DNE21+

AIM/Enduse

Japan

WITCH

0
DNE21+

CO2 marginal abatement cost (US$2005/tCO2)

300

32

Marginal abatement
costs if theaggregated NDCs areachieved most costefficiently:
16$/tCO2 by WITCH,
6$/tCO2 by DNE21+

Korea/S.Africa/Australia

Source: B. Pizer, J. Aldy, R. Kopp, K. Akimoto, F. Sano, M. Tavoni, COP21 side-event; MILES project report for Japan- The marginal abatement costs vary across models for some countries, but can be comparable for many countries/regions.
- The CO2 marginal abatement costs of the NDCs of OECD countries are much higher than the marginal cost for the casethat the aggregated NDCs are achieved most cost-efficiently (globally uniform marginal abatement cost).

We should have some flexibilities in emission pathways
while keeping the goal of net zero CO2 emissions
50

Wide deployments of low
carbon technologies

Business as Usual (BaU)

CO2 emissionis [GtCO2/yr]

40
Submitted NDCs

30
+2℃ stabilization under climate
sensitivity of 2.5℃ (Noexceedance of 580 ppm)

acceleration of technology
and social innovations

20

10+2℃ stabilization under climate
sensitivity of 3.0℃ (Noexceedance of 500 ppm)
450 ppm CO2eq stabilization

Toward net zero CO2 emissions

0

-10
2010

2050
2060

Flexible considerations on the2100 timing for net zero emissions
2110

2160

2210

2300

Submitted NDCs

2260

- Many of the studies show the difficulty in meeting net zero emissions by 2100.
- More reasonable and realistic targets will have more flexibility in terms of the timing to achieve net CO2
zero emissions.
- Having the flexibility, technology and social innovations (social innovations will be also induced bytechnologies) should be accelerated harmonizing with sustainable development.

33