Lucky for us, Jon Schroeder is on the case, and is bringing us the top ten green skyscrapers.
 

10. The Urban Cactus, Rotterdam

The Urban Cactus is a residential project in the Netherlands that will offer 98 residential units on 19 floors. Thanks to the staggered design of the curvy balconies, each unit's outdoor space will get plenty of light from the sun. That means that this greenscraper really will be green when all the residents' gardens are in bloom. While this tower may lack in the technology department, its carbon-mitigation potential still looms high thanks to all the photosynthesis happening on the porch. Plus, its white color will help to mitigate the urban heat island effect.

9. 340 on the Park, Chicago

When 340 on the Park opens later this year in Chicago, it may become the first residential greenscraper in the city to meet LEED standards. The building is sure to be a wealthy EcoGeek's dream-come-true. If you have $700K to throw down on a 1600 square-foot condo, you can enjoy low utility bills thanks to the building's fully insulated windows and rainwater capture system. And the most awesome amenity is the multi-storey winter garden starting on floor 25.

8.Waugh Thistleton Residential Tower, Londo

On the other side of the pond, the Waugh Thistleton Architects have an eco-residential building in the works as well. This design will employ helical wind turbine technology previously on featured on EcoGeek. Four turbines attached to one side of the tower have the potential to generate 40,000kW hrs a year, more than 15% of its energy needs.

7.The Burj al-Taqa (Energy Tower), Dubai

If this 68-story super greenscraper becomes a reality, it may become the tallest of all eco-towers, thanks to the proposed 200-foot wind turbine that will sit atop the building. Burj al-Taqa will occupy #22 on the world's tallest buildings list should it gets the green light.

Wind isn't this greenscaper's only bag, however. Solar panels will cover a 161,459 square foot artificial island chain connected to the building and seawater will power Burj al-Taqa's air conditioner!

6. The Hearst Tower, New York City

The Hearst Tower became New York City's first skyscraper to achieve LEED Gold accreditation from the USGBC when it opened its doors last year. 80% of the steel used to make the behemoth was recycled. On the inside, the floors and ceiling tiles are made from recycled materials as well.

The diamond shapes on the building's fa?de aren't just for show either. The diagonal grid required fewer steel beams to achieve the same rigidity as a conventional skyscraper, and the design allows more natural light to enter the tower.

What's more, rainwater is collected on the roof and is funneled into a 14,000-gallon tank in the basement. The Hearst gathers enough water from the sky to account for 50% of the tower's usage. It's pumped into the cooling system, used for irrigating plants and for the innovative water sculpture in the main lobby.

5.The CIS Tower, Manchester England

Formerly on featured on EcoGeek, the CIS Tower outdoes the pretty much anyone in solar. Weighing in with over 7,000 panels on the fa?de and 24 wind turbines on the roof, the CIS Tower will be able to produce 10% of its energy needs all on its own.

4.The Lighthouse Tower, Dubai

The Dubai International Financial Centre Lighthouse Tower plans to use 4000 photovoltaic panels on the south facing fa?de as well as three mega 225 kilowatt wind turbines to meet its electricity needs. Other details are sparse, if it was under construction this definitely would have broken into the top three.

3. Bank of America Tower, New York City

The designers of Bank of America Tower, Cook + Fox Architects, are hoping to one-up the Hearst Tower by going for LEED Platinum certification. We'll see if they pull it off next year, when the building is slated to cut the red ribbon. Like the Hearst, The BOA tower will also use rainwater capture and floor-to-ceiling windows for natural lighting?but it will also employ even more EcoGeeky technologies. Natural gas fuel cells will create on-site electricity, and sunlight-sensing LED lights will maximize efficiency.

For more info on all of NYC's greenscrapers, check out this short film directed by Carol Willis titled Green Towers for New York: From Visionary to Vernacular

2. The Pearl River Tower, Guangzhou, China

Another greenscraper designed to harness winds at lofty heights, the Pearl River Tower will use internal wind turbines to keep the lights on. Fashioned like a giant wing, the tower pushes air through wind tunnels on two of the building's 71 stories. This eco-marvel of a building will also employ geothermal heat sinks, ventilated facades, waterless urinals, integrated photovoltaics and daylight responsive controls when it opens in late 2009.

1.The Bahrain World Trade Center Towers, Kingdom of Bahrain

Three 96-foot propellers suspended between the towers will supply the 42-storey spires with over 1100 megawatts per year. The shape of the building itself will create an accelerated airflow for the jumbo blades. Here are some virtual views of the Arabian Gulf from various levels of the building. Real views can be appreciated later this year, when the building opens.