12 February 2009Japan Low-Carbon Society Scenarios toward 2050 Project Symposium

Norichika KANIEGraduate School of Decision Science and TechnologyTokyo Institute of Technologykanie@valdes.titech.ac.jp

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Research Questions for the Team

Q1.What level is required for the long-term target to avoid dangerous climate change?

Q2.What level of target is required for Japan?

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AnswerIn order to limit the negative impact of

climate change…

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90％80％70％60％

It is safer to prepare the situation where

Japan should reduce emissions by at least 60％to about 90％ in 2050 (from ‘90 level)Taking uncertainty also into account.

How much to reduce?

Step 1: How much GHGs have to be reduced at global level?

Co-relations between GHG stabilization level and impact level (level of temperature increase) is calculated

Step 2: Emission reduction differentiation in 2050 based on the above calculation result

⇒ Emission reduction to be required for Japan

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Step 1 starts with UNFCCC

ARTICLE 2: OBJECTIVE 

The ultimate objective of this Convention and any related legal instruments that the Conference of the Parties may adopt is to achieve, in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time‐frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner. 

ARTICLE 3. 3. The Parties should take precautionary measures to anticipate, prevent or minimize the causes of climate change and mitigate its adverse effects. 

ARTICLE 4: COMMITMENTS

All Parties, taking into account their common but differentiated responsibilities and their specific national and regional development priorities, objectives and circumstances, shall…

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Step 1 starts with UNFCCC

ARTICLE 2: OBJECTIVE 

The ultimate objective of this Convention and any related legal instruments that the Conference of the Parties may adopt is to achieve, in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time‐frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner. 

ARTICLE 3. 3. The Parties should take precautionary measures to anticipate, prevent or minimize the causes of climate change and mitigate its adverse effects. 

ARTICLE 4: COMMITMENTS

All Parties, taking into account their common but differentiated responsibilities and their specific national and regional development priorities, objectives and circumstances, shall…

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Avoiding dangerous climate change

For avoiding “dangerous” impact of climate change, we need to keep temperature increase below 2℃

Dangerous

ＩＰＣＣ-TAR

Impacts on vulnerable ecosystems such as vegetation shift and breech of coral leaf

Impacts on various sectors including water resources, agriculture, forestry and human health in many regions around the world.

Severe and irreversible impacts such as THC shutdown, collapse of Greenland Ice sheet and West Antarctic Ice sheet

Extremely dangerous

Potential impacts by temperature increase from pre-industrial level (ΔT ℃)

○ΔT≦1℃： Impacts to vulnerable ecosystems are likely to occur even with ΔT as much as 1℃. Therefore, if we aim at avoiding the potential impacts to the vulnerable ecosystems, ΔT needs to be kept below 1℃. On the other hand, considering the temperature increase by about 0.6℃ in the 20th century and the projected changes in population and economic activity in the 21st

century, it is prohibitively difficult to keep ΔT less than 1℃.

○ΔT≦２℃： With ΔT by 2 – 3 ℃, it is indicated that adverse impact will emerge globally. Therefore, for proactively preventing global-scale adverse impact from occurring, it is necessary to keep ΔT less than 2℃. Furthermore, some studies suggest steep increases in adverse impacts with ΔT by about 2℃. From the point of view of effectively preventing wide spread of adverse impacts, it makes sense to choose 2℃ as upper limit of tolerable ΔT.

○３℃＜ΔT： According to several scientific evidences, with ΔT larger than 3℃, threshold to keep stability of climate system is crossed over and probability of singular events such as THC shutdown will increase. Since exceeding this level of ΔT increases the risk of severe and irreversible adverse impacts globally, we must avoid it definitely. It should be noted, however, thatresearch results regarding levels needed for keeping climate system stability are limited, and therefore more science knowledge development is in demand.

Based on the scientific knowledge above, the idea of keeping ΔT below 2℃can be a starting point of discussion about long-term stabilization target. 8

Emission path by AIM/Impact [Policy]

0

5

10

15

20

25

3019

90

2000

2010

2020

2030

2040

2050

2060

2070

2080

2090

2100

Year

CO

2eq

(GtC

/yr)

CS=1.7 CS=2.0 CS=2.5CS=2.6 CS=3.0 CS=2.6&475ppmCS=2.6&500ppm CS=2.6&550ppm CS=2.6&650ppmBaU

0

5

10

15

20

25

30

1990

2000

2010

2020

2030

2040

2050

2060

2070

2080

2090

2100

Year

CO

2eq_

KP

(GtC

/yr)

CS=1.7 CS=2.0 CS=2.5CS=2.6 CS=3.0 CS=2.6&475ppmCS=2.6&550ppm CS=2.6&650ppm CS=2.6&500ppmBaU

0

0.5

1

1.5

2

2.5

3

3.5

4

1990

2000

2010

2020

2030

2040

2050

2060

2070

2080

2090

2100

Year

Tem

pera

ture

incr

ease

(199

0=0.

6)

CS=1.7 CS=2.0 CS=2.5CS=2.6 CS=3.0 CS=2.6&475ppmCS=2.6&550ppm CS=2.6&650ppm 系列1BaU

0100

200300

400500600

700800

9001000

1990

2000

2010

2020

2030

2040

2050

2060

2070

2080

2090

2100

Year

CO

2eq

conc

entra

tion

CS=1.7 CS=2.0 CS=2.5CS=2.6 CS=3.0 CS=2.6&475ppmCS=2.6&550ppm CS=2.6&650ppm CS=2.6&500ppmBaU

Cosmopolitanism

Nationalism

Com

munitarianism

Rationalism

/Individualism

International cooperation

World government

Balance of power

Globalism

Dispersal of power

Closed regional blocsClash of civilizations ／Localism

Global marketplace

international political change according to ideological stances

Cosmopolitanism

Nationalism

Multilateral Cooperation Scenario

Close to the idea of Contraction and Convergence

・Convergence year 2050, 2070, 2100

Economy FirstScenario

Close to the idea of Intensity target

・intensity improve at the same degree throughout

・intensity converge in 2070 or 2100

• liberal market

• Intensity target if there is any

• Industry or sectoral reduction if there is no cap

• Economic efficiency first. Reduce cost effectively.

• All participation principle, the rest is market principle.

• Open Regionalism• Equity per person• Common but differentiated responsibility• environment first• Equal effort• Global tax, etc.

6 patterns of differentiation

CommunitarianismRationalism/Individualism

Furthermore…Taking uncertainty into account

Global Differentiation

C&C 2050C&C 2070C&C 2100Improve GHG/GDPGHG/GDP converge 2070GHG/GDP converge 2100

Sensitivity

1.51.72.02.52.63.0

Ultimate goal

2℃

2.2℃

2.6℃

Emission reduction of Japan 2050: range of required reduction for 2℃ target

0

200

400

600

800

1000

1200

1400

1600

1800

1990 2000 2010 2020 2030 2040 2050

Mt-

CO

2eq

18％～44％reduction 60％～80％

reduction

Cases for climate sensitivity 3℃・・・82％ to 93％reduction required

Invitation to "Cool Earth 50“May 24, 2007In order to achieve the objective of the United Nations Framework Convention on Climate Change to stabilize the level of greenhouse gas concentrations in the atmosphere, we must curb the global greenhouse gas emissions to the same level as the capacity of natural sinks. Bearing this in mind, I propose setting a long-term target of cutting global emissions by half from the current level by 2050 as a common goal for the entire world. Considering the fact that current global emissions are more than double the capacity of natural sinks, which means that gas concentrations in the atmosphere will only increase, it is imperative that we first share this goal internationally.

Emission path for 50% reduction in 2050Global Environment, vol12, No.2

Case1,2 from ‘90 level, Case3,4 from 2000 level, Case5,6 from 2004 level 15

Required GHG emission reduction and its path for Japan in case of halving GHG emissions (Kyoto six gases) in 2050

Required GHG emission reduction for major emitters (from 1990 level)

C&C 2050

Japan USA EU Russia AI China India Brazil R of Korea

Case1 （2.2℃） 85% 88% 83% 94% 88% 35% -89% 62% 73%Case2 （2.3℃） 85% 88% 83% 94% 88% 35% -91% 61% 73%Case3 （2.2℃） 83% 86% 80% 93% 86% 26% -118% 56% 69%Case4 （2.4℃） 83% 86% 80% 93% 86% 26% -118% 56% 69%Case5 （2.3℃） 81% 85% 78% 92% 85% 19% -137% 52% 66%Case6 （2.6℃） 81% 85% 78% 92% 85% 19% -137% 52% 66%

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Individualism

Idealism

Realism

Multilateral Cooperation Scenario

Economy First Scenario

Communitarianism

Required emission reduction for Japan in case of halving global emissions in 2050 (C&C 2050)

2050 2030

From 1990 From 2000 From 1990 From 2000

Case1 （2.2℃） 85.2% 85.9% 65.4% 67.2%

Case2 （2.4℃） 85.0% 85.7% 51.6% 54.1%

Case3 （2.3℃） 82.9% 83.8% 61.9% 63.9%

Case4 （2.5℃） 82.9% 83.8% 49.5% 52.1%

Case5 （2.4℃） 81.4% 82.3% 58.6% 60.7%

Case6 （2.6℃） 81.4% 82.3% 43.1% 46.0%

Required emission reduction for Japan in case of halving global emissions in 2050 (Equal Intensity improvement Rate)

2050 2030

From 1990 From 2000 From 1990 From 2000

Case1 （2.2℃） 92.0% 92.4% 79.4% 78.3%

Case2 （2.3℃） 91.9% 92.3% 71.2% 69.6%

Case3 （2.2℃） 90.8% 91.3% 77.1% 75.9%

Case4 （2.4℃） 90.8% 91.3% 69.7% 68.1%

Case5 （2.3℃） 90.0% 90.5% 75.0% 73.7%

Case6 （2.6℃） 90.0% 90.5% 65.6% 63.8% Required emission reduction for Japan in case of halving global emissions in 2050 (C&C 2100)

2050 2030

From 1990 From 2000 From 1990 From 2000

Case1 （2.2℃） 78.2% 79.3% 63.2% 65.1%

Case2 （2.3℃） 78.0% 79.1% 48.6% 51.2%

Case3 （2.2℃） 75.0% 76.3% 59.2% 61.3%

Case4 （2.4℃） 75.1% 76.3% 46.0% 48.8%

Case5 （2.3℃） 72.8% 74.2% 55.5% 57.7%

Case6 （2.6℃） 72.8% 74.2% 38.8% 41.9%

Intensity improvement rate (per year)period 2010-2050

Case1 （2.2℃） -6.34%

Case2 （2.3℃） -6.31%

Case3 （2.2℃） -6.01%

Case4 （2.4℃） -6.01%

Case5 （2.3℃） -5.80%

Case6 （2.6℃） -5.80%

2050年世界半減の時の日本の排出削減必要量

AnswerIn order to limit the negative impact of

climate change…

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90％80％70％60％

It is safer to prepare the situation where

Japan should reduce emissions by at least 60％to about 90％ in 2050 (from ‘90 level)Taking uncertainty also into account.

Issues still to be solved

Mid-term targets are indispensable for realizing low-carbon society

As they are related to emission reduction path and emission stabilization levels International politics, international negotiation, international institutions do matter, too.

Target-setting and the valueTarget-setting = to what extent we can accept the impact of climate change. How can we scientifically introduce value judgments into target-setting process?

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Emission Reduction Path

Early peak-out is required for low stabilization level. A key is the extent to which emission reduction can be achieved before 2050.

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Emission Stabilization Levels

Next decade or two is vitally important for low stabilization level, according to IPCC AR4.

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Issues still to be solved

Mid-term targets are indispensable for realizing low-carbon society

As they are related to emission reduction path and emission stabilization levels International politics, international negotiation, international institutions do matter, too.

Target-setting and the valueTarget-setting = to what extent we can accept the impact of climate change. How can we scientifically introduce value judgments into target-setting process?

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