Both Sydney and Melbourne have posted impressive scores in a new ranking of the sustainability performance of the world's leading cities.

A new report released by sustainable design consultancy Arcadis reveals that Australia’s major cities are faring well compared to other parts of the developed world when it comes to sustainability and efficiency performance.

The inaugural Arcadis Sustainable Cities Index seeks to provide a more comprehensive appraisal of the sustainability performance of the world’s leading cities, on the grounds that the concept of “sustainability” should be interpreted far more broadly than is conventionally the case, and reflect “a variety of different dimensions.”

In order to reflect this broader sustainability concept, Arcadis assessed a total of 50 cities around them world across the three sub-indices of People (quality of life issues), Planet (environmental impact) and Profit (economic stability), using a total of 20 input indicators.

The People sub-index looked at features of a city affecting the quality of life of residents, including transportation systems, literacy levels, health, education,income inequality, work-life balance and amount of green spaces or nature strips within cities.

The Planet sub-index primarily relates to environmental impact, covering levels of energy consumption, usage of renewable sources of clean energy, levels of green house gas emissions, recycling, potable water quality, air pollution and sanitation, while the third sub-index of Profit covers business and economic factors, including GDP per capita, a city’s economic significance in a broader context, ease of conduction business, property and living costs as well as quality of transportation infrastructure.

Arcadis sourced data from some of the world’s most reputable international sources in order to provide inputs for the sub-indices, including the United Nations, the World Health Organization, the World Bank and the International Labour Organization.

While no Australian cities made the index’s top 10 cities in terms of sustainability, the two most populous cities of Sydney and Melbourne were both in the top 20, pegged at 11 and 17 respectively.

Sydney came out ahead of every single US city on the index, given that none for them took positions in the top 10, while Melbourne beat many of the world’s other leading cities in terms of sustainability performance, including Chicago, New York, Tokyo, San Francisco and and Los Angeles.

The reasonably strong performance of Australian cities on the index in terms of sustainability performance comes as welcome news following the recent release of a government-commissioned report pillorying efficiency levels in the country’s  property and building sectors.

Although Australian cities fared reasonably well in this latest assessment of overall sustainability, another recent report indicates that there remain significant performance deficits where improvements can still be made.

The government-commissioned National Energy Efficiency Building Project by pitt&sherry and the Swinburne University of Technology found that Australia’s built environment suffers from widespread failure to satisfy existing efficiency criteria, chiefly due to a “pervasive culture of mediocre energy performance across the Australian building industry.”

When it came to the sub-indices, Sydney and Melbourne performed especially well in the People category, taking out fourth and eighth place respectively, and reasonably well in the Profit category, taking 16th and fifth position respectively.

The two cities fared less impressively in the Planet category, with Sydney ranked 18th and Melbourne 23rd.

European cities performed best in the overall index, taking out all five of the top positions, with Frankfurt coming first, followed by London, Copenhagen, Amsterdam and Rotterdam. Several Asian mega-cities also enjoyed strong rankings, including Seoul in seventh place, Hong Kong in eighth place and Singapore in 10th position.

Arcadis is a global leader in the field of natural and built asset design and consultancy, and ranked sixth in Engineering News-Record’s list of the top 225 international design firms for 2014.