SINGAPORE is ranked the most sustainable city in Asia, and second in the world, according to the Sustainable Cities Index 2016 from global design and consulting firm Arcadis.
This marked a major improvement from its 10th global position last year when the index was first launched.
Zurich has maintained the top-ranked city globally, while the third, fourth and fifth places are taken up by Stockholm, Vienna and London respectively in the overall global ranking.
Among Asia-Pacific cities, Seoul is ranked seventh globally, followed by Hong Kong (16th) and Canberra (18th). In the 2015 report, Singapore was ranked lower than Seoul (seventh) and Hong Kong (eighth).
No North American city made it into the index's top 20.
The Sustainable Cities Index was conducted by the Center for Economics and Business Research and explores social (People), environmental (Planet) and economic (Profit) demands to develop an indicative ranking of the world's leading cities.
Apart from being the most sustainable city in Asia, Singapore also tops two out of the three sub-indices in Asia: Planet and Profit.
But factors such as high cost of living and lack of work-life balance cause Singapore to be placed seventh in Asia and 48th in the world for the "People" sub-index.
Arcadis Singapore city executive director Eugene Seah pointed out that Singapore has its unique set of challenges as an island nation, such as limited land to develop and a lack of natural resources.
"Therefore, Singapore has to be innovative and cultivate a durable and productive management system in order to stay sustainable moving forward," he said.
There has been a major drive in Singapore to be more sustainable on several fronts - ranging from smart logistics planning and master-planning, smart and green buildings, and construction productivity.
John Keung, CEO of the Building and Construction Authority of Singapore, said: "We are heartened that Singapore's green building movement and green building masterplans have played a pivotal role in placing Singapore on the world map as the most sustainable city in Asia.
"It was not just a conscious, top-down approach but also the commitment and close collaboration of the public, private and people sectors that made such an achievement possible for Singapore," he said.
"We will continue to push the boundaries with more focus on research and innovation, as well as more engagement with building users to initiate ground-up action for the green building movement."