|
In a Wednesday session on using biochar as a climate stabilization measure, Nathaniel Mulcahy of World Stove explained that over 2 billion people worldwide cook on open fires. Constant open fires not only pose a carbon emissions problem, they pose a health risk, increasing respiratory distress and incidences of asthma. If they cooked their meals on a simple pyrolysis stove, instead of an open flame, they could sequester between 1-3 tons of carbon per person, per year, which is about what you'd get from an acre of pine forest, and significantly reduce indoor particulate.
Along the same lines, Mulcahy noted that 20 million tons of rice straw were just burned in Egypt every year. Ash from open fires retains as little as 3-5% of the original mass of carbon in the original plant material, and the nutrients are used up quickly. Char produced through pyrolysis, on the other hand, can retain 20-50% of the original mass of carbon, which can then stay in soil a long time and improve fertility.
And here, I should mention the ways in which combustion (burning things), digestion and decomposition are all similar. Each of these processes take carbon that was originally breathed in by plants, solidified by those plants into sugars, possibly eaten by a series of animals, and then returned to a gaseous state in the form of carbon dioxide (CO2) or methane (CH4). Having mentioned digestion and decomposition separately, I should proceed directly to tell you that decomposition is a word for digestion by microbes (bacteria and fungi,) and so while we think of it separately, it works about the same and isn't some inevitable, mechanical process.
The climate-relevant question is how quickly this cycling of carbon on land and through organisms (pdf) proceeds and how much of it is going on at a given time.
|
STATE BLOGS
Powered by: SoapBlox