Sucking carbon dioxide out of the air: Neat idea, but impractical - The Washington Post
Humanity is making dismal progress on curbing its greenhouse gas emissions. That’s led some scientists to dream up
zany geoengineering schemes to avert drastic climate change. One promising idea involved sucking carbon dioxide
out of the air. Alas, new research suggests, this
isn’t very practical:
You can strip CO2 from the air with chemical filters or by boosting reactions occurring as rocks weather. Colin Axon of Brunel University in Uxbridge, UK, and Alex Lubansky at the University of Oxford estimated what it would take to remove the 30 gigatonnes of CO2 we emit every year.
That would mean processing 75,000 Gt of dry air. Scaling up proposals to filter air would use 180 Gt of clean water per year, depriving 53 million people of water, on top of the 66 per cent of the world’s population who will face water shortages by 2025.
To make matters worse, mopping up carbon dioxide with chemical filters would use an enormous amount of energy and be prohibitively expensive. A
study last year in Nature pegged the cost of carbon dioxide removal at about $600 per ton, which is about seven times more pricey than even
the high-end estimates of carbon taxes deemed necessary to curtail the world’s emissions.
