As more of Asia's population heads for the cities, Singapore can offer clues for planning urban spaces to ensure they remain livable, including by controlling pollution.
"If the city is not well done, immediately you get air pollution. You get traffic congestion and also you spend a lot of time on roads, rather than spending time at home or on recreation," said Dr. Liu Thai-Ker, chairman for the Centre for Liveable Cities and a former head of Singapore's Urban Redevelopment Authority and its Housing Development Board.
"On top of that, the cumulative long-term effect of such a city multiplied by many, many cities obviously will spell the doom for our planet," he said on the sidelines of CNBC's EnergyFuture brainstorming event Tuesday.
Planning for growing urbanization is an urgent topic. A hundred years ago just 2 out of 10 people on Earth lived in cities. Today more than half the world's population lives in cities and that number is expected to rise to around 70 percent by 2050, according to Hot Spots 2025, a report prepared by the Economist Intelligence Unit for Citibank.