Forget elaborate, potentially hazardous geoengineering schemes for countering global warming: injecting aerosols into the atmosphere or seeding the ocean with iron is just too risky.
Instead, a new study suggests we should borrow an idea from ancient Amazonian farmers: biochar. Far from a hippie-environmentalist-crackpot "save the world" scheme, researchers have found biochar could be the real deal, able to sequester over a billion tons of carbon from the atmosphere each year.
Biochar (shown in the image above) is charcoal made from biomass that is slowly cooked at high temperatures though a process called pyrolysis. Unlike regular biomass, which releases carbon dioxide a decade or two after it breaks down, biochar is much more stable and can retain it for hundreds of years.
While some CO2 is released into the atmosphere during the cooking process, at least half gets locked up during pyrolysis, and is then buried.
The study, appearing today in the journal Nature Communications, shows that if biochar production was applied on a global scale, it could save up to 1.8 billion metric tons of CO2 annually -- that equals 12 percent of the total amount of greenhouse gas emissions produced by human activity in a year.
Besides gobbling up greenhouse gases, biochar works wonders on soil fertility. "Biochar can improve agricultural productivity, particularly on low-fertility and degraded soils where it can be of especial utility to the world's poorest farmers," the researchers, led by Dominic Woolf of Swansea University in the United Kingdom, wrote.
The organic material works its magic on the dirt in a myriad of ways, from reducing the losses of nutrients and agricultural chemicals in run-offs, to improving the water-holding capacity of soils. And, as an extra bonus, biochar can even be produced from biomass waste, such as rice husks, sugar cane, or manure.
http://news.discovery.com/earth/biochar-could-put-huge-global-dent-in-greenhouse-gases.html