ABSTRACT
This chapter investigates what is currently known and what remains to be researched about the major impacts of biochar on climate change. A greater persistence of charred than uncharred organic matter (OM) is the foundation of biochar systems' capacity to reduce greenhouse gas (GHG) emissions, and thereby mitigate climate change. The chapter provides an overview of observations of priming in biochar systems, possible mechanisms that may drive priming, interactions with other carbon (C) sources in soils, including plant roots and added OM, and implications for the expected magnitude and duration of priming. Except for the remediation of methane (CH4) emission from biomass which is instantaneous and quasi permanent, greater persistence is the basis for greater emission reductions and therefore the basis for the role of biochar systems in climate change mitigation. The chapter provides clear guidance on what types of best management practices (BMPs) will ensure that biochar projects avoid the potential pitfalls of negative impacts.
