The Singapore Index (SI)

Over the last 30 years, the world’s urban population has been rapidly increasing and is forecasted to reach nearly 5 billion by 2030 (Seto et al., 2012). This has been accompanied by rapid urban land expansion, which is occurring on average twice as fast as urban population growth (Seto et al., 2012). Therefore, if current urban population growth rates remain unchanged, urban land cover is expected to triple in size by 2030 (Seto et al., 2012). This increase would exacerbate biodiversity loss due to even more habitat fragmentation and altered local climates, among other things. However, cities still support some species and can make efforts to conserve them. How then, should cities protect urban biodiversity and ensure their efforts are making progress? Thinking along those lines, I recalled reading a publication by the Centre for Liveable Cities (CLC) (where I used to intern) that discussed biodiversity conservation efforts in cities. Two words caught my attention: “Singapore Index”.

What is the Singapore Index (SI)?

No, this is not about Singapore’s financial stock market. Instead, it involves taking stock of biodiversity in cities. As the name suggests, the SI (also known as City Biodiversity Index) was conceived in Singapore! First proposed at the Conference of Parties (COP) to the Convention of Biological Diversity (CBD) in 2008, the SI is a self-assessment tool with a scoring system for cities to measure and evaluate their progress in biodiversity conservation by comparing with a baseline year (Chan et al., 2014). In 2010, the SI was formally endorsed by the COP (Kohsaka et al., 2013). With the SI, cities can benchmark their progress in reducing the rate of biodiversity loss in urban environments, measure their ecological footprints and identify gaps in biodiversity information (Rodricks, 2010).

In short, it consists of two components (Chan et al., 2014):

  • “Profile of the City” which includes background information of the city
  • 23 indicators in three categories: (1) native biodiversity in the city; (2) ecosystem services provided by biodiversity in the city; and (3) governance and management of biodiversity in the city.

To know more about the SI and indicators used, you can read the user’s manual here! However, if reading a lengthy document doesn’t appeal to you (I totally understand), check out these two videos (will embed), where Dr Lena Chan, Director of the National Biodiversity Centre (NBC) under the National Parks Board, explains how the SI works and why it is useful:

Implementation of the SI

Unsurprisingly, Singapore was one of the first to implement the SI. How did Singapore fare? Not too bad! She scored well in governance, but could improve in terms of ecosystem services and freshwater supplies (Tok, 2011). Other cities have also implemented the SI, including 14 in Japan, India’s Mira Bhainder and Canada’s Edmonton (Kohsaka et al., 2013). However, there were some challenges when it came to implementation. After all, no two cities are exactly alike. Challenges include no clear definition of what defines a “natural area” and “fragmentation”, lack of data on native and invasive species, and difficulties in (1) calculating ecosystem services and (2) determining how much budget to allocate to general environmental causes and biodiversity-specific activities (Kohsaka et al., 2013).

For example, Yokohama is Japan’s second-largest city, making regular comprehensive surveys of biodiversity and terrestrial ecosystems difficult to conduct and seen as unrealistic due to budget constraints (Kohsaka et al., 2013). Indeed, lack of biodiversity data and financial constraints are major challenges in applying the SI especially for cities in developing countries. Even Edmonton, Alberta, Canada, received a relatively low biodiversity and ecosystem services score (Kohsaka et al., 2013). However, one must consider the climate (Edmonton is cold!). This is a reminder that caution should be exercised when comparing scores across cities.

Final thoughts

Overall, despite inevitable compatibility issues with the SI, I feel that it is still a useful tool. Cities may choose to add indicators to the SI or even be inspired to create their own indices to best suit their contexts. Ultimately, the main takeaway is that there is no “one size fits all” index, because it is nearly impossible to include indicators that all cities will have data on. Make it too broad, and the SI will lack depth. Make it too specific or rigid, and it will lack flexibility and applicability. At least the SI recognises the importance of biodiversity in urban environments and spurs cities to keep track of their conservation efforts, a crucial element in the pursuit of sustainable urban development.


Chan, L. et al (2014). User’s Manual on the Singapore Index on Cities’ Biodiversity (also known as the City Biodiversity Index). Singapore: National Parks Board, Singapore.

Kohsaka, R. et al (2013). Indicators for management of urban biodiversity and ecosystem services: city biodiversity index. In Urbanization, biodiversity and ecosystem services: challenges and opportunities (pp. 699-718). Springer Netherlands.

Rodricks, S. (2010). Singapore City Biodiversity Index. Retrieved from

Seto, K. C. et al (2012). Global forecasts of urban expansion to 2030 and direct impacts on biodiversity and carbon pools. Proceedings of the National Academy of Sciences, 109(40), 16083-16088.

Tok, C. (2011). City Biodiversity Index. Retrieved from

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