London-based architecture office EcoLogicStudio harnesses photosynthesis to remove pollution from the air with this living curtain, designed to rest over building facades. The studio's Photo.Synth.Etica "urban curtain" is a photobioreactor – an incubator for algae, which carries out the naturally carbon-sequestering process of photosynthesis. The micro-algae feeds on daylight and air, capturing carbon dioxide molecules and storing them within the curtain, while producing oxygen and releasing it back into the surrounding air. The curtain optimises this natural process, capturing approximately one kilogram of carbon dioxide per day — the equivalent to that of 20 large trees. EcoLogicStudio envisages the curtain being integrated into new and existing buildings, and doubling as a sunshade.