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Showing posts with the label geoengineering

Fake Plastic Tree Refuses to Die

Just like that cheap plastic Christmas tree that mum trots out every year, stories about the scientifically questionable CityTree refuse to die.  This press release masquerading as news has been rehashed and reprinted with little scientific analysis by Wired, Forbes, Dezeen, CNN - and - so -  many - others that it made me throw up in my mouth a little and I had to stop googling it.

As I wrote the other day, these CityTrees make almost impossible claims to purify air of nearly every pollutant, all the way from particulate matter down to carbon dioxide.  This last one is the most challenging to accept, as it has been reported that each fake plastic tree "has the air purifying power of 275 normal trees". That is a direct quote from once-respected newspaper The Independent. Yes, that The Independent.

It is claimed that each one of these devices removes 240,000 kg of carbon dioxide from the air every year, equivalent to a small forest.  This means, however, that about one tonne (o…

Fake Plastic Trees

Air pollution is a big deal - it kills millions annually - but we aren't going to make progress in dealing with it by planting fake plastic trees in the middle of the world's cities.
When you attempt to reduce air pollution it is much easier to do it at the concentrated source - and easier yet to stop these compounds being formed all together - than it is to do once they've been released and diluted to one part per million or billion.  But yet again we see another story / press release about a tech startup trying to do just this.

The Crown Estate claim to have planted a small number of their CityTrees in several first world cities - cities with air quality issues, yes, but not on the level of their counterparts in the developing world.  These devices, like many others out there, are designed to suck in dirty air and purify it. They then release clean air to mix back in with the urban plume, where it can modestly dilute the remaining pollutants.  When you try and picture t…