A French and Dutch design firm called The Cloud Collective has come up with an amazingly innovative and creative way to extract damaging Co2 from busy roadways and convert it into oxygen, using algae. The algae absorb the Co2 emissions, and combined with the absorption of sunlight, convert it into oxygen through the process of photosynthesis. The benefits don't end there. Their innovative design allows for the algae to be even more useful once it has matured. They claim it can be used for bio-diesel, medication, food, and more. The design itself is unobtrusive, and in a lot of ways, attractive. The system makes for a literally “greener” look on the vast grey concrete of an overpass. To top it all off, the whole thing is solar powered. They may have paved paradise and put up a parking lot, but technology like this is making way for the re-introduction of much-needed oxygen producing flora in our urban environments.