The Charcoal Challenge. Regulation of global carbon cycles by vegetation fires
Year: 2011
Type: preprint
Abstract: Vegetation fires release some fraction of the carbon in the biomass back to the atmosphere as CO2 and deposit some of the carbon onto the ground as charcoal, or pyrogenic carbon. It is an open, but not unanswerable, question as to whether the formation of pyrogenic carbon can e ectively sequester carbon from atmospheric CO2. In this work the question in conceptualised in terms of the global Charcoal Challenge, which deals with the scientific and socioeconomic questions associated with increasing the refractory black carbon pool at the expense of the atmospheric carbon pool. Within this paradigm three specific and urgent Charcoal Challenges are examined: i) the feasibility of lowering atmospheric CO2 by biochar production, ii) the tension between nature’s use of fire to distribute carbon between longterm black carbon and short-term atmospheric pools and humans’ need to suppress fire, and iii) the premise that black carbon is a sink for CO2 only if its rate of formation exceeds its rate of decay, otherwise it is a source. It is shown how the thermal decomposition of cellulose, the major constituent of vegetation, during fires acts as a thermokinetic oscillator that regulates the global distribution of carbon between atmospheric and black carbon reservoirs. It is concluded that we cannot yet assume with certainty that the global black carbon reservoir is a carbon sink.
Source: arXiv (Cornell University)
Author: Rowena Ball
Language: English
Topic: Fire effects on ecosystems
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDGs: Climate action, Life on land
Open Access status: green
OpenAlex ID: W2137080231