Beware China’s ‘anti-smog tower’ and other plans to pull pollution from the air
China has a skyscraper-sized air-purification tower, London has NO2-eating paint. But are tech pollution solutions any good, or a handy distraction from the deeper issues – one that suits goverments and industry alike?
An air-purifying tower the size of a small high-rise has been built in the city of Xi'an, China. Reports from the scientists behind the project seem at first glance to be rather positive, offering a technological route to clean pollutants out of the air at the sort of scale that could help an entire city. But as there isn’t any hard data publicly available to support the claim, for now a dose of scepticism is likely in order.
This isn’t the first project to use a technological or natural intervention to try and clean up nitrogen oxides pollution (NOx) and other pollutants from ambient air. In India water cannons have been used recently in an attempt to wash out particles, while in London NOx-eating paint has been promoted as a solution to harmful nitrogen oxides. And many cities have mooted the planting of more trees and shrubs as a route to cleaning up the air.
All of these, and indeed the purifying tower, are underpinned by at least some plausible science. A tower that filters the air no doubt will take tiny harmful particles out of the air, titanium oxide paints do react with NOx, and trees do act as sinks for air pollution. However, the more important but often neglected question is whether the effects really make a useful difference.
