M.M. Faten Hashem Karim<br />What makes a city sustainable? It's a combination of commitment to clean energy, green spaces and emissions reduction. But it's also there in the little things. Giving back to the community, supporting local businesses, and switching to eco-friendly lifestyles can also make a difference.<br /> From the island nation of Singapore to the thriving city of Dubai and the glamorous European city of Amsterdam, here's our list of some of the most sustainable cities in the world.<br />1- Reykjavik, Iceland<br />Iceland takes sustainability very seriously. This stunning country with its exotic landscape aims to become carbon neutral by 2040. Currently, about 90 percent of its energy needs are met by renewable sources - hydroelectricity and geothermal energy. The Land of Fire and Ice knows a thing or two about harnessing its intrinsic energy to help reduce emissions and carbon footprint. Even its cuisine relies on fresh, local, seasonal produce, fueled by fresh water and clean air.<br />2- Singapore<br /> Singapore is leading the way when it comes to reimagining urban spaces. Whether it's setting aside prime real estate for green space (as in Marina Bay) or ensuring that all buildings adhere to strict green building standards, the island nation ensures that development and sustainability go hand in hand. It is currently building a unique smart forest city on 700 hectares complete with green spaces, public housing, forest corridors, community agriculture and more.<br />3- Dubai and Abu Dhabi, United Arab Emirates<br />Both emirates may seem unlikely contenders for the world's most sustainable cities, but they have significantly reduced their environmental footprint since the early 2000s. Today, Dubai and Abu Dhabi rank among the top 20 most sustainable cities, thanks to their shift towards clean energy. A combination of government action, extensive research and collaboration has led to the development of Masdar City, a solar-powered community city in the middle of the desert.<br />4- Brisbane, Australia<br />Brisbane was named Australia's most sustainable city in 2014 and 2016, and for good reason. The city, along with the capital, Canberra, has been at the forefront of engaging the entire community in adopting a sustainable lifestyle. By influencing lifestyle changes, both large and small, both cities have been able to create a paradigm shift. From cycling, recycling, switching to green energy and conducting school-level awareness campaigns, the City of Brisbane has taken several steps towards a green future.<br /><br />5- Amsterdam, Netherlands<br /> Amsterdam conjures images of famous canals surrounded by Dutch Baroque buildings. Every nook and cranny here is filled with history and art. The city is also a treat for cyclists. Over the years it has worked to develop infrastructure that encourages walking and cycling, and the result has been a relatively emissions-free transportation system. In fact, Amsterdam has the second highest percentage of people who walk and bike to work, with 58% of its residents walking or cycling to their offices. And that's not all: the city is working to reduce carbon emissions by 55% by 2030 and 95% by 2050, while ensuring that 80% of homes are powered by sustainable energy by 2030.