Green Options

Editor’s note: This post was written by Max Ajl, and originally published on Wednesday, March 25, at SolveClimate.

A couple of weeks ago, we discussed the possibilities of biochar - burning organic waste, such as wood chips, left-over crop residue or even manure at extremely low oxygen levels and high temperatures in order to produce charcoal and biogas. The charcoal would go into the ground, increasing soil fertility, while the gas would be an effective energy source, making good use of detritus that would otherwise decompose, returning its carbon to the atmosphere.

I suggested that although the technology was still distant from full-scale implementation, it had considerable promise as a way to draw-down carbon from the atmosphere.

Well, environmental writer George Monbiot has demurred. He wrote in the Guardian yesterday that biochar advocates have been “suckered.” They promote “an even crazier use of woodchips.” They wish to “turn the planet’s surface into charcoal.” They are a wild band of “magical thinkers” who wish to “destroy the biosphere in order to save it.”

Remember, this is Monbiot, a serious analyst of anthropogenic global warming, not Bjorn Lomborg or a mercenary from the Heartland Institute. This man isn’t “supposedly” in the coalition to avert disastrous warming - he’s part of it, through and through.

So what’s he in a tizzy about? A lot of nothing, it turns out, since he’s battling with a straw-man that most biochar researchers don’t take even remotely seriously.

Biochar. It’s been around for a little while, but is only beginning to gain traction in climate change and global warming circles for its carbon negative properties. Biochar is a charcoal soil additive that is created through the “thermal treatment” (burning) of biomass residues such as rice and peanut shells, tree bark, sludge from paper mills, and other organics.

The next revolution in agriculture and greenhouse gas reduction may be a 3000-year old farming practice of adding biomass charcoal to the soil. The practice was re-discovered by archeologists who were studying a site in the central-Amazon basin. Some 1500 years earlier the indigenous tribes had enriched the soil using charcoal from animal bone and tree bark. The soil remains today some of the richest and most fertile soil yet found.

Scientists from the American Chemical Society have begun a five-year study of the use of biomass charcoal for soil enrichment in order to understand its impact on fertilization, soil carbon changes, crop productivity and any impact on the microorganisms in the soil.

The practice holds promise for several reasons:

1. Soil need only be fertilized once with this method and the effect lasts for hundreds to thousands of years.
2. The resulting agricultural method is carbon-negative since the enriched soil traps and holds carbon in the soil, which may offer significant benefits to decreasing global warming from agriculture and reducing greenhouse gases in the atmosphere.