Previous Work - Wilson Center
Population and Climate Change: Relationships, Research, and Responses Brian C. O’Neill Institute for the Study of Society and Environment, National Center for Atmospheric Research (NCAR) & International Institute for Applied Systems Analysis (IIASA) Collaborators: Mike Dalton (NOAA), Leiwen Jiang (Brown Univ.), Shonali Pachauri (IIASA) Presented at the Woodrow Wilson International Center for Scholars 20 February 2008
Population and the Climate Problem • Slowing population growth would reduce greenhouse gas emissions significantly in the long term • Lower fertility and slower population growth would ease adaptation to climate impacts • Population-related policies can be considered “win-win” with respect to climate change
Population and Emissions: Historical • New statistical analyses support roughly proportional effect of population size on national emissions • Also supports positive effect of urbanization level, and possibly of age structure
Recent Econometric Results, Demography and National CO2 Emissions Elasticity of CO2 Emissions Study Pop. Size Martinez-Zarzoso et al., 2007 Fan et al., 2006
% Urban
Household % Working Size Age
+0.55 (EU) +
+
Cole & Neumayer, 2004
+0.98
+0.70
Rosa et al., 2004
+1.02
York et al., 2003
+0.98
Shi, 2003
+1.43
Dietz & Rosa, 1997
+1.15
+0.62
+ -0.50
Not Sig.
Not Sig. +0.63
Studies based on 86-208 countries, mixture of cross-sectional and panel analyses, 1975-2000.
Recent Econometric Results, Demography and National CO2 Emissions Elasticity of CO2 Emissions Study Pop. Size Martinez-Zarzoso et al., 2007 Fan et al., 2006
% Urban
Household % Working Size Age
+0.55 (EU) +
+
Cole & Neumayer, 2004
+0.98
+0.70
Rosa et al., 2004
+1.02
York et al., 2003
+0.98
Shi, 2003
+1.43
Dietz & Rosa, 1997
+1.15
+0.62
+ -0.50
Not Sig.
Not Sig. +0.63
Studies based on 86-208 countries, mixture of cross-sectional and panel analyses, 1975-2000.
Population and Emissions: Future The IPCC SRES Scenarios Carbon emissions, 2000-2100, 6 (of 40) scenarios
4 Qualitative Storylines (A1, A2, B1, B2; no climate policy) 4 Combinations of Driving Forces 40 Quantitative Scenarios
Source: IPCC SRES, 2000.
16
Special Report on Emissions 14
Scenarios, 2000
SRES A2 ('high') SRES B2 ('medium') SRES A1/B1 ('low') IIASA GGI A2 Hilderink A2 ('high') Hilderink B1 ('medium') Hilderink A1 ('low') Hilderink B2 ('lowest') IIASA 2001 (0.95) IIASA 2001 (Median) IIASA 2001 (0.05) UN 2003 High UN 2003 Medium UN 2003 Low
12
10
8
6
4
2
Year Year
Source: O’Neill, 2004.
2100
2095
2090
2085
2080
2075
2070
2065
2060
2055
2050
2045
2040
2035
2030
2025
2020
2015
2010
2005
0 2000
Population (billions) Population in billions
IPCC Population Assumptions vs. More Recent Projections
Population Assumptions in Recent Scenarios
Source: IPCC AR4, Mitigation Report, 2007.
Population-Emissions Relationship in SRES
Cumulative Fossil Fuel Emissions, GtC
3000
2500
A1 2000
A2 1500
B2 1000
B1 500
0 5
7
9
11
13
Global Population, 2100 (billions)
15
17
Population-Emissions Relationship in SRES
Cumulative Fossil Fuel Emissions, GtC
3000
2500
A1 2000
A2 1500
B2 1000
Higher population, higher emissions
B1 500
0 5
7
9
11
13
Global Population, 2100 (billions)
15
17
Population-Emissions Relationship in SRES
Cumulative Fossil Fuel Emissions, GtC
3000
Same population, higher emissions
2500
A1 2000
A2 1500
B2 1000
Higher population, higher emissions
B1 500
0 5
7
9
11
13
Global Population, 2100 (billions)
15
17
Population and Emissions: The PET Model Households Consumption & Savings Capital & Labor Final Goods
CO2 Emissions
Labor Capital
Final Goods Producers Energy Consumption Investment Materials Government Exports & Imports
Intermediate goods producers Oil&Gas Coal Electricity Refined Petroleum Materials
Source: Dalton et al., 2008; Dalton & Goulder, 1998.
Per Capita 1998 Dollars
U.S. Per Capita Household Income 35,000 30,000 25,000 20,000 15,000 10,000 5,000 0
Labor
(Data: Cons. Exp. Survey)
Population and the Climate Problem • Slowing population growth would reduce greenhouse gas emissions significantly in the long term • Lower fertility and slower population growth would ease adaptation to climate impacts • Population-related policies can be considered “win-win” with respect to climate change
Population and Emissions: Historical • New statistical analyses support roughly proportional effect of population size on national emissions • Also supports positive effect of urbanization level, and possibly of age structure
Recent Econometric Results, Demography and National CO2 Emissions Elasticity of CO2 Emissions Study Pop. Size Martinez-Zarzoso et al., 2007 Fan et al., 2006
% Urban
Household % Working Size Age
+0.55 (EU) +
+
Cole & Neumayer, 2004
+0.98
+0.70
Rosa et al., 2004
+1.02
York et al., 2003
+0.98
Shi, 2003
+1.43
Dietz & Rosa, 1997
+1.15
+0.62
+ -0.50
Not Sig.
Not Sig. +0.63
Studies based on 86-208 countries, mixture of cross-sectional and panel analyses, 1975-2000.
Recent Econometric Results, Demography and National CO2 Emissions Elasticity of CO2 Emissions Study Pop. Size Martinez-Zarzoso et al., 2007 Fan et al., 2006
% Urban
Household % Working Size Age
+0.55 (EU) +
+
Cole & Neumayer, 2004
+0.98
+0.70
Rosa et al., 2004
+1.02
York et al., 2003
+0.98
Shi, 2003
+1.43
Dietz & Rosa, 1997
+1.15
+0.62
+ -0.50
Not Sig.
Not Sig. +0.63
Studies based on 86-208 countries, mixture of cross-sectional and panel analyses, 1975-2000.
Population and Emissions: Future The IPCC SRES Scenarios Carbon emissions, 2000-2100, 6 (of 40) scenarios
4 Qualitative Storylines (A1, A2, B1, B2; no climate policy) 4 Combinations of Driving Forces 40 Quantitative Scenarios
Source: IPCC SRES, 2000.
16
Special Report on Emissions 14
Scenarios, 2000
SRES A2 ('high') SRES B2 ('medium') SRES A1/B1 ('low') IIASA GGI A2 Hilderink A2 ('high') Hilderink B1 ('medium') Hilderink A1 ('low') Hilderink B2 ('lowest') IIASA 2001 (0.95) IIASA 2001 (Median) IIASA 2001 (0.05) UN 2003 High UN 2003 Medium UN 2003 Low
12
10
8
6
4
2
Year Year
Source: O’Neill, 2004.
2100
2095
2090
2085
2080
2075
2070
2065
2060
2055
2050
2045
2040
2035
2030
2025
2020
2015
2010
2005
0 2000
Population (billions) Population in billions
IPCC Population Assumptions vs. More Recent Projections
Population Assumptions in Recent Scenarios
Source: IPCC AR4, Mitigation Report, 2007.
Population-Emissions Relationship in SRES
Cumulative Fossil Fuel Emissions, GtC
3000
2500
A1 2000
A2 1500
B2 1000
B1 500
0 5
7
9
11
13
Global Population, 2100 (billions)
15
17
Population-Emissions Relationship in SRES
Cumulative Fossil Fuel Emissions, GtC
3000
2500
A1 2000
A2 1500
B2 1000
Higher population, higher emissions
B1 500
0 5
7
9
11
13
Global Population, 2100 (billions)
15
17
Population-Emissions Relationship in SRES
Cumulative Fossil Fuel Emissions, GtC
3000
Same population, higher emissions
2500
A1 2000
A2 1500
B2 1000
Higher population, higher emissions
B1 500
0 5
7
9
11
13
Global Population, 2100 (billions)
15
17
Population and Emissions: The PET Model Households Consumption & Savings Capital & Labor Final Goods
CO2 Emissions
Labor Capital
Final Goods Producers Energy Consumption Investment Materials Government Exports & Imports
Intermediate goods producers Oil&Gas Coal Electricity Refined Petroleum Materials
Source: Dalton et al., 2008; Dalton & Goulder, 1998.
Per Capita 1998 Dollars
U.S. Per Capita Household Income 35,000 30,000 25,000 20,000 15,000 10,000 5,000 0
Labor
(Data: Cons. Exp. Survey)
