As the world becomes more aware of the risks of climate change and the importance of sustainable energy sources, individuals and communities are increasingly taking measures to reduce their carbon footprint. Some are building "passive homes", to take advantage of natural sun and wind patterns, while others are installing solar panels or windmills, to power their homes. But never before has there been an entire "green" city - one that relies solely on renewable energy sources and smart design elements, to eliminate its carbon footprint.

Welcome to Masdar City, the world's first carbon neutral city that is being constructed in the most unlikely of locations - the oil-rich Abu Dhabi in the United Arab Emirates (UAE)! While the presence of fossil fuel has helped spur UAE into one of the world's wealthiest countries, its officials are well aware that the oil wells will eventually run dry, leaving them with no choice, but to resort to renewable sources of energy.

So, in anticipation of the future, Abu Dhabi officials decided to collaborate with Masdar, a clean-energy research corporation and Foster & Partners, a British architecture firm that focuses on innovation and integrated design to build this unusual city.

The project, which began 6 years ago, is only 15% complete, but it demonstrates that such a city is possible. Given that Masdar City is situated in a desert where summer temperatures can get as high as 36°C (96°F), the planners began by coming up with clever ways to reduce the need for energy draining air-conditioners.

By establishing Masdar City atop a hill, they were able to take advantage of the breeze from the nearby Persian Gulf. Short, narrow streets maximize shade, while terra cotta grills cover windows to keep the hot sun at bay. Then there are the 150-foot tall wind towers that help siphon the breeze down to the streets, cooling them down substantially. According to the developers, these seemingly small measures have not only helped lower the temperatures of Masdar City by about 10°C compared to the surrounding desert, but also, reduced air-conditioning needs by up to 55%. The designers tackled the remaining power requirements by building a massive solar plant, as well as installing panels on every possible building surface.

Then came the challenge of conserving water, which is of ultra importance given that Abu Dhabi gets an average of just 2.5 inches of rain annually. In Masdar, 80% of "greywater" from washing machines, sinks, baths, and showers, is purified and re-cycled. In order to minimize wastage of water or electricity, the designers eliminated faucet handles and light switches inside buildings. Instead, everything is motion activated! Officials say that this feature has reduced electricity consumption by 51%, and water usage by 55%. Also, all the buildings are constructed from materials like sustainable palm wood wherever possible, and designed to meet the equivalent of the LEED Gold certification, one of the highest ratings from the U.S. Green Building Council.

In order to keep the environment free of toxic gases, visitors to the City are asked to leave their cars on the outskirts and hop aboard the driverless electric pod shuttles that are situated underground. The city has also been constructed such that it is easy to walk or bike around.

But building a cutting edge city like Masdar is not cheap. By the time it is completed in 2025, it will have cost a mind-boggling $20 billion USD. And that is just to house 40,000 permanent residents and 50,000 daily commuters! The high cost has led to some experts even speculating whether Masdar City will ever being completed. Even if the UAE government does end up subsidizing the entire building cost, the question of whether the hi-tech city will be able to sustain itself financially thereafter, remains in doubt.

But that does not mean the experiment is a total bust. Masdar City does provide some interesting design innovations that could easily be adopted by even older, densely packed cities like London, New York or Cairo, and enable them to become more sustainable. Environmentalists believe that any focused effort toward carbon-neutral city planning could help change the world, and hope that Masdar City will provide the inspiration for other countries to start thinking differently.