Biochar systems for carbon finance - an evaluation based on Life Cycle Assessment studies in New Zealand

Abstract:  Biochar produced from the pyrolysis of biomass and applied into soils (biochar) can, under some conditions, improve soil functions and sequester carbon (C) over millennia.  In New Zealand, if 80% of the available biomass residues were converted into biochar, about 1.7 Mt CO₂ could be sequestered annually.  This represents ~2.4% of NZ's total annual greenhouse gas (GHG) emissions.  However, the trade-offs associate with alternative uses of biomass need to be assess from a life cycle perspective, particularly when considering policymaking.

Several approaches for incentivising biochar carbon sequestration were explored.  These include using conservative carbon-accounting estimates, issuing temporary credits, establlshing buffer funds, creating carbon credit multipliers, and inventing a new unit such as ppm CO₂ reductions for recognising atmospheric CO₂ removals as opposed to avoiding GHG emissions.  While biochar technology is currenly facing numerous barriers for acceptance in carbon markets, its future is promising since biochar production also offers potential in the agriculture, energy and waste management sectors.