A handful of major world cities stand out as leaders. This infographic focuses on the contest between London, New York, Vancouver, Copenhagen, Amsterdam, and Stockholm. Three of these cities made it into our list of the top 10 smart cities on the planet (two others were runners-up). In each of these cities, there are notable statistics worth mentioning. Amsterdam has one bike for every 0.73 people, Copenhagen has legislation requiring all new buildings to have green roofs (this will add 5,000 square meters of vegetation), and only 44% of New Yorkers own a car, compared to 95% of Americans overall. That latter point is because of the city's robust public transportation infrastructure--and its clogged streets.

Stockholm wins the alternative transportation war, with a whopping 93% of residents walking, biking, or taking public transportation to work. This can be partially attributed to the city's congestion tax, its bike-sharing system, a well-used public transportation system, and general walkability. In contrast, Vancouver and New York still see the majority of residents driving to work.

In Amsterdam, residents are apparently diligent about conserving water, with just 32.2 gallons of water used per person per day. It also has the lowest water leakage rate out of all the cities listed. London has the highest because of its old pipes, and residents are starting to speak out.

New York has the highest carbon emissions per person (8.6 tons), but it's still significantly lower than the U.S. average of 14.5 tons. European cities are on average more carbon-conscious; they average 5.2 tons per person. London, Copenhagen, and Amsterdam all exceed that average, while Stockholm emits just 3.62 tons per person.

So which city is the greenest? It's hard to say. In many respects, Stockholm beats the competition. But the cities need to be considered in their regional contexts. New York is environmentally conscious compared to most other U.S. cities, and Vancouver is known as one of the greenest cities in Canada. All of the cities listed have features that should be emulated by other cities. As the world's population becomes more urban, these models of what can be done will become increasingly important.

Source: Co.Exist