ITU‐T's Technical Reports and Specifications 15 2.1 Environment and sustainability Cities represent 75% of energy consumption and 80% of CO2 emissions on a global basis, and represent the largest of any environmental policy challenge7. Therefore, sustainability and the environment are the most critical components in the functioning of any city. There is a clear distinction between the two terms (i.e. sustainability and the environment) that needs to be made. According to the Brundtland Commission, sustainable development refers to the environmental, economic and social aspects, whereas environmental aspects refer to the physical and biological surroundings of a city. The major attributes included under this dimension are the following: city infrastructure and governance energy and climate change pollution and waste social, economy and health Multiple studies conducted in this field suggest that each of these attributes encompasses a series of more granular categories and components, as described below8 9 10 11 12 13. Table 1 – Categories and components of the environment and sustainability dimension City infrastructure and governance Policy and management Infrastructure Integrated environmental management Strategy Municipal administration Effective conservation Urban planning Buildings and physical infrastructure Mobility, transportation and traffic Public safety Energy and climate change CO2 emissions Energy CO2 from energy production Emissions per capita Energy performance Conservation ____________________ 7 http://www.theguardian.com/sustainable‐business/smart‐cities‐innovation‐energy‐sustainable 8 Esty D.C., Levy M.A., Kim C.H., de Sherbinin A., Srebotnjak T., Mara V. (2008). 2008 Environmental Performance Index. New Haven: Yale Center for Environmental Law and Policy. 9 http://ec.europa.eu/environment/europeangreencapital/applying‐for‐the‐award/evaluation‐process/index.html#sthash.QXukMUww.dpuf 10 IBM smart cities web site http://www.ibm.co m/smarterplanet/us/en/smarter_ cities/overview/index.html 11 http://www.forrester.com/pimages/rws/reprints/document/82981/oid/1‐LTEQ9N 12 Murakami S., Kawakubo S., Asamai Y., Ikaga T., Yamaguchi N., and Kaburagi S. (2011). Development of comprehensive city assessment tool: CASBEE‐City, Building Research & Information (2011) 39(3), 195‐210. 13 http://euronet.uwe.ac.uk/www.sustainable‐cities.org/indicators/ECI%20Final%20Report.pdf