An alternative to cleaning up emissions from vehicles directly could be to deploy technologies which remove pollution from the ambient air. For example, a number of companies are developing photo-catalytic treatments which remove pollutants from the air in the presence of sunlight. These treatments can be applied to a range of surfaces, for example roofing tiles, roofing felt or even the surface or roads. Similarly, developers are also looking at other ways of cleaning air in urban environments. Studio Roosegarde, a Dutch design company, has developed a smog free tower consisting of an air purifying tower which sucks in pollution and expels clean air. The extracted pollution is, somewhat bizarrely, turned into pieces of jewellery.

Other examples of air purification technologies include the air purifying billboards and pavement and vertical forests. Although many cities like the space for large green areas in their downtown core, building forests vertically along with skyscrapers, has become a very interesting development to filter pollutants from the air. Some cases have been already developed by the Italian architect Stefano Boeri.

Main stakeholders doing R&D: Dürr, Co2 Solutions, Shell, Chevron, NRG Energy, Carbon Engineering, ClimateWorks

Main stakeholders in the market: Dürr, Co2 Solutions, Shell, Chevron, NRG Energy, Carbon Engineering, ClimateWorks