1. A new perspective on global carbon emission inequality: insights from global interpersonal carbon Gini-index
Presented By: Tianpeng Wang
Institute of Energy-Environment-Economic, Tsinghua University

2. Introduction
Global emission inequality is a debate focus related to abatement responsibility
Emission inequality researches mainly fall into two categories
Emission inequality across countries: Developed vs Developing
Emission inequality across persons: Rich vs Poor
global interpersonal emission inequality
Consider emission inequality both from across countries view and across persons view
Global Interpersonal Carbon Inequality

3. Introduction Traditional methods to measure carbon inequality
emission
population
Traditional methods to measure carbon inequality
Carbon Lorenz curve and carbon Gini-index
Atkinson Index
Theil’s entropy measure
…….
Concepts related to emission
Production based emission vs Consumption based emission
Influence of transferred emission on global interpersonal emission status

4. Methods Figure 1. Summarize of the methodlogy process
Emulate income distribution curve of various countries
Build the relationship between income and emission based on literature and some assumptions
Construct different countries’ emission distribution curve combined with emission data
Aggregate emission distribution curves of all the countries
Construct the global Lorenz curve and calculate the global carbon Gini-index

5. Methods: Emulate income distribution curve of various countries
2-gamma fitting method
Lognormal fitting method
Data needed:
Income distribution data
GDP per capital data
Income Gini-index of different countries
Data source: World Development Indicator (WDI)
World Income Inequality database (WIID)

6. Electricity consumption
Methods: Build the relationship between income and emission based on literature and some assumptions
Country
Variable 1
Variable 2
Year
Elasticities
Australia
Income
CO2 emission
0.55
Energy consumption
0.59
Expenditures
0.7
0.74
0.78
Brazil
1.0
Denmark
1995
0.48
0.51
0.86
India
2004
1.008
Japan
1999
0.64
Netherland
1990
0.63
0.83
New Zealand
1980
0.4
Norway
1973
0.72
Spain
2000
United State
0.85
South Africa
Electricity consumption
0.32
China
2002
0.84
United Kingdom
0.432
Philippines
2000&2006
0.8
Finland
GHG emission
2006
0.6
Classification
Elasticities
Developed countries
Developing countries
LDC

7. Methods: Construct different countries’ emission distribution and global Lorenz curve
Figure 2. Emission distribution curve and global carbon Lorenz curve

8. Results: The trend of global Gini-index from production based emission side view
Figure 3. Variance trend of global interpersonal carbon Gini-index

9. Results: Comparsion of production based and consumption based global emission inequality
Figure 4. Production based and consumption based emission classes of different countries in global emission distribution, 2011
Production based emission
Consumption based emission
year
2011
2007
2004
Intragroup inequality
0.279
0.262
0.242
0.243
0.221
0.204
-- Developed countries group
0.296
0.300
0.299
0.264
0.266
0.260
-- Developing countries group
0.552
0.561
0.556
0.525
0.524
0.521
-- LDC group
0.548
0.554
0.544
0.533
0.541
0.535
Between-group inequality
0.276
0.318
0.356
0.315
0.373
0.416
Residual
0.036
0.027
0.021
0.028
0.022
0.014
Total
0.590
0.607
0.618
0.586
0.616
0.633

10. Results: Sensitivity analysis of income elasticities
Figure 5. Influence of unit alteration from different income elasticities on Gini-index based on production side emission and consumption side emission

11. Discussion and Limits
The value of carbon Gini-index came down from 0.67 in 1980 to 0.59 in 2014
Decline of emission inequality at global scale
Mainly because of the narrowing between-groups emission gap
The global carbon inequality status is still very severe with Gini-index is around 0.6 in recent years
Provides a theoretical basis for the abatement responsibility assignment on inter- personal level rather than on national level across countries
Main limits of this research: the rough assumption of relationship between emission and income.

12. Thank You