Charcoal in soil, alo known as Terra preta, Terra preta do Indio, Terra preta nova, Bio-char, has proven to have many benefits.
Regarding to its reactivty, carbon exists in nature in three functionally different types.
- The type that easily emit energy, as gasoline crude oil or petroleum gas.
- The type that only give away energy if it is heated, as diamonds, charcoal or fossil coal (bitumene, anthracite and the like)
- The type that doesn't react unless energy is added, as carbon dioxide
Today (2008), the carbon dioxide concentration in the amosphere is about 385 ppm. A relatively safe level is estimated by James Hansen & al. to be less than 350 ppm.
Tipping points
- Complex systems doesn't behave as simple systems.
- They excert sudden changes that not are predictable in time, but are very foreseeable in type
- Examples are:
- The Gulf stream
- The Siberian tundra
- The Monsoon system
The amounts
- Currently (2008) the atmpospheric carbon dioxide level is about 285 ppm
- A ppm of carbon dioxide corresponds to about 2.12 Gt carbon.
- Every year, about 8 Gt carbon (as carbon dioxide) is emmited into the atmosphere.
- Thus, allowing for that some is absorbed by the oceans, the atmospheric content of carbon dioxide increase with 2-3 ppm each year.
- Nobody knows for sure which level gives the next tipping point.
Emission reductions of any size, even a total stop,
will never reduce the atmospheric carbon content
- As carbon dioxide is stable, decrease can only be done by sequestration.
- Technical systems (CCS, Carbon capture and storage ) can not sequester carbon dioxide at levels as low as the content of the atmosphere. They require much higher concentrations.
- Besides, to set up a technical system normlly require fossil fuels
- Plants routinely sequester carbon dioide from the atmosphere. Around 300 ppm is their normal operating level. But plants die, and their carbohydrates will be consumed by microorganisms, returning them to carbon dioxide in the atmosphere.
- To creata plant, you only need
But
carbohydrates can be conserved, if they are converted to
charcoal, which will last in the soil for 40,000 years or more.
Charcoal in the soil also has a lot of benign effets on the soil:
Charcoal production is an easy technique. It is well-known since the invention of fire.
There are a lot of mehods
- But caution has to be taken
Careless charring (as careless firing) emits methane, a 22 times stronger greehouse gas than carbon dioxide
