Cities included in the Asian Green City Index.

Cities included in the Asian Green City Index.

The Economist Intelligence Unit, sponsored by Siemens, released a first version of an Asian Green City Index last month, which compares environmental performance across 22 cities in Asia, five of which are in China (excluding Hong Kong).  This work is based on similar “Green City Index” efforts by EIU and Siemens, including a Latin American Green City Index in November 2010, which evaluates 17 cities across Latin America.

Defining ‘environmental performance’

Before delving into the nitty gritty of the Index, I thought it’d be helpful to try and provide some clarification around what is meant by ‘environmental performance indicators,’ as quantitative tools like metrics and indices seem to be gaining in popularity amongst governments seeking more information by which to gauge progress toward policy targets. Performance indicators are the most useful for policy-makers in that they are focused on defined goals or targets and quantify progress and effectiveness of state or national policies, reporting on the outcome of policy actions (Peterson et al., 2001). In effect, environmental performance indicators condense environmental data into pertinent information that then allows for monitoring, target setting, tracking performance improvements, benchmarking and reporting (Jasch, 2009). Performance indicators are often used to compare indicators of environmental stresses and quality with targets and objectives that are defined according to national policies and international agreements (Alberti and Parker, 1991). To summarize key characteristics of environmental performance indicators, De Leeuw (2002) describes five key elements:

1. provide a representative picture of environmental conditions, pressure on the environment or society’s responses;

2. be simple and easy to interpret, based on readily available data that enables to show trends over time. Trends in indicator values give insight in what is happening in the environment and whether it is improving;

3. be defined in such a way that contributions from individual components and sectors can be recognized in the indicator value;

4. be consistently used within the driving-force-pressure-impact-response (DSPIR) framework;

5. have a target value to be reached in the foreseeable future.

De Leeuw’s (2002) description is only one definition out there, although I do take issue with criteria number five, “have a target value to be reached in the foreseeable future.” Targets set too low may be attainable in an immediate future, but they may not necessarily reflect best practice or ideal conditions.  But, nevertheless, it provides a more clear idea of what is meant by a performance indicator, which I feel authors such as the ones of the Asian Green City Index sometimes fail to clarify.

Performance scorecard for Beijing in the Asian Green City Index. Source: EIU, 2011.

Performance scorecard for Beijing in the Asian Green City Index. Source: EIU, 2011.


The Index employs 29 indicators across eight categories — energy and CO2, land use and buildings, transport, waste, water, sanitation, air quality, and environmental governance — to determine where each city falls in five “performance bands:” well below average, below average, average, above average, and well above average.”   The indicators are a mixture of quantitative and qualitative measures: 14 are quantitative and can be measured (such as greenhouse gas emissions or air quality), while the remaining 15 are qualitative and assess policies and plans (such assessments of a cities’ green building standards).

The quantitative indicators are normalized on a scale of 0 to 10, with the best city scoring ten points and the worst zero.  The qualitative indicators are assessed by an expert panel that ranks the cities’ performance on a scale of 0 to 10.

The indicators are then weighted — greater weightings (33 versus 25 percent) were allocated to indicators in the transport, sanitation, and environmental governance categories.

“Performance” bands are then determined by:

Well above average: Scores more than 1.5 times the standard deviation above the mean
Above average: Scores between 0.5 and 1.5 times the standard deviation above the mean
Average: Scores between 0.5 times the standard deviation below and 0.5 times the standard deviation above the mean
Below average: Scores between 0.5 and 1.5 times the standard deviation below the mean
Well below average: Scores more than 1.5 times the standard deviation below the mean.

Key findings of the Asian Green City Index

What did the researchers determine?  Taking a look at the performance scores of the countries, the authors did not find drastic variation in performance.  Fourteen of the 22 cities compared appeared in the same performance band for at least five of the eight categories considered.  They point to this result as suggestive of uniform, comprehensive policies in place within the cities evaluated.  But I wonder if such a finding begs into question whether the level and scale of the data and indicators actually reveals nuances in performance that might better explain performance drivers.  At any rate, the authors found the following conclusions:

  • Wealthier cities tend to perform better.  Singapore topped the Index rankings and was also the fourth richest city amongst the group of 22, at a per capita GDP of US $36,500.
  • A decoupling of income and resource consumption occurs at a certain level of per capita GDP, reflecting a sort of environmental Kuznets for consumption.  When per capita income reaches around US $20,000, average resource consumption declines. I found this result to be particularly interesting, considering per capita income in the United States in 2009 was around $39,626, yet resource consumption is amongst the highest globally (the United States ranks fifth in terms of largest ecological footprint).  If this trend holds, particularly for rapidly developing Asian economies, reduced-consumption development paths could mean that countries like China and India could avoid Western growth trajectories.
  • Policy execution matters. I found this to be the least compelling argument because it seemed as if the authors weren’t able to clearly isolate drivers for better policy performance in cities like Singapore and Hong Kong based on one year of data. They point to government transparency, strong civil service, and resources as examples of factors that lead to better environmental policy execution in the top-performing cities, but it seems to me that these are generalizations rather than concrete drivers.  However, what I did find to be useful is the features of “exemplar projects” and narratives of what countries and particular cities are doing to address environmental concerns.

How do Chinese cities compare?

For China specifically, the authors chose cities that are among the wealthiest in China (Beijing, Shanghai, Nanjing, Wuhan, Guangzhou).  Unsurprisingly, these five cities had the highest energy consumption out of the entire group of 22 cities.  Have the highest energy consumption out of all cities compared in the Index. Most Chinese cities only performed at “average” or “below average”  in the categories, but Wuhan, Nanjing and Beijing did perform “above average” in the Water category and Guangzhou performing “above average” in the Sanitation category.  A word of caution for the water category: the Index only uses two indicators – water consumption per capita and water system leakages to gauge performance.  However, it is unclear as to whether the water consumption numbers are industrially-based or take into account water used for water-intensive processes like electricity production.  Shanghai was the only city that performed “well below average” in the energy and CO2 category, the worst out of all cities in the study.  The authors point to the fact that nearly half of Shanghai’s energy consumption is from coal-based electricity.

The Index is probably not that representative of China’s environment on a whole, nor in most Chinese cities, but  it does provide a useful regional comparison of where Chinese cities stand in relation to other Asian cities in terms of some of these environmental criteria.

Stay tuned for the summer release of an Environmental Performance Assessment report my colleagues at I at the Yale Center for Environmental Law and Policy, Columbia University’s Center for International Earth Science Information Network, City University of Hong Kong, and the Chinese Academy for Environmental Planning that takes a look at environmental performance indicators in Chinese provinces. I also have an upcoming piece in the 12th Edition of the China Environment Series that will take a look at our experiences attempting to measure environmental performance in Chinese provinces as well as implications for tracking progress toward environmental goals and targets in China’s 12th Five-Year Plan.

Alberti, M. and J.D. Parker. 1991. Indices of environmental quality: the search for credible measures. Environmental Impact Assessment Review. 11:95-101.
De Leeuw, F.A.A.M. 2002. A set of emission indicators for long-range transboundary air pollution. Environmental Science & Policy. 5:135-145.
Economist Intelligence Unit. 2011. Asian Green City Index. Available here.
Peterson, P.J., W. P. Williams, L. Yang, W. Wang, S. Hou, R. Li, and J. Tan. 2001. Development of indicators within different policy contexts for endemic arsenic impacts in the People’s Republic of China. Environmental Geochemistry and Health. 23: 159–172.