Imagine if every time you threw out your lawn and garden waste, you were actively fighting global warming. That’s the capacity a new soil amendment technology hopes to unleash across the world.
This potentially-revolutionary method of making fertilizer that almost completely removes greenhouse gas emissions has received a grant from Bloomberg Philanthropies to be incorporated into 7 major cities’ landscaping programs.
Making “biochar” as it’s called, has been modernized recently in Sweden, and is done by putting grass trimmings, hedge clippings, tree branches, or any other kind of yard waste, into an enclosed space and “pyrolyzing it” in such a way as to avoid the rapid oxidation of CO2.
Turned into a charcoal-like substance, it’s not only carbon negative, meaning it removes more CO2 than it produces, but also more effective soil nutrition than other traditional soil amendments like nitrogen-phosphorus fertilizer.
On Tuesday, Bloomberg Philanthropies announced it was awarding grants of $400,000 to seven major cities in Scandinavia and the U.S. to implement the winning project of the charity’s 2014 Mayor’s Challenge: The Stockholm Biochar Project.
Each city will receive implementation and technical support from Bloomberg to develop city-wide biochar projects and engage residents in the fight against climate change. It’s expected to produce 3,750 tons of biochar, all from lawn and garden waste from city parks, median strips, and other green spaces, which would sequester almost 10,000 tons of CO2 per year – the equivalent of taking 6,250 cars off the roads.
Normally, municipal lawn and garden waste is trucked to landfills where it will decompose and release all the carbon it absorbed through its life back into the atmosphere, as well as other gasses from the bacteria feeding on it. With a biochar plant however, every branch and twig thrown into the sophisticated-yet-straight-forward furnace is having its carbon captured almost forever.