At four am the other day I lay awake (again) thinking about C02 reduction...as you do. I thought about Branson's latest self-promotional scheme and how it actually has some merit. It would contribute to easing his business man's conscience of course...but imagine if a scientist cracks it in our lifetime.
The winning technology would have to have no ecological footprint of its own. So I thought of a set of giant solar and hydrogen cell powered turbines in the Australian outback. These giant 'desert flowers' would have huge fans inside them engineered to cleverly circulate the atmosphere through spiral filters coated with C02 consuming bacteria.
The spiral filters would have panels that could be replaced or recycled. Each panel would contain a vast array of high surface area material. The only example I could think of was tungsten spirals used in light filaments. Some durable equivalent would work well. I thought too that the bacteria might have a lifespan and could need protecting from the elements so the giant flower could close (with the retractable petals) in times of inclement weather or sand storms.
So, seeing as I've just read Biomimicry I felt the structure should follow a biological example...and the Rafflesia came to mind.