M.S. Research

Pine FTIRPredicting pyrogenic organic matter mineralization from its initial properties and implications for carbon management (in prep):  Predicting pyrogenic carbon (PyC) or biochar stability from its initial properties is critical for evaluating and managing terrestrial carbon stocks. We compared transmission mode FTIR to proximate analysis data and H:C and O:C ratios for predicting C mineralization. PyC produced at 7 different temperatures from 6 different feedstocks, in addition to the original feedstock materials, were incubated for 3 yr in a sand matrix. A C debt or credit ratio was calculated by comparing the C remaining in the incubated PyC sample to the C remaining in the incubated original feedstock.

droppedImage_3Climate Change Impact of Biochar Cook Stoves in Western Kenyan Farm Households: System Dynamics Model Analysis (Environmental Science and Technology): Cook stoves that produce biochar as well as heat for cooking could help mitigate indoor air pollution from cooking fires and could enhance local soils, while their potential reductions in carbon (C) emissions and increases in soil C sequestration could offer access to C market financing. We used system dynamics modeling to (i) investigate the climate change impact of prototype and refined biochar-producing pyrolytic cook stoves and improved combustion cook stoves in comparison to conventional cook stoves; (ii) assess the relative sensitivity of the stoves’ climate change impacts to key parameters; and (iii) quantify the effects of different climate change impact accounting decisions.

droppedImage_4Biochar projects for mitigating climate change: an investigation of critical methodology issues for carbon accounting (Carbon Management): Biochar is a potential tool in our fight against climate change, driven by its high carbon stability and supported by its roles in bioenergy and soil fertility. We consider methodology aspects of biochar systems used for carbon management and investigate the criteria for establishing additionality, baselines, permanence, leakage, system drivers, measurement, verification, economics and development for successful stand-alone projects and carbon offsets.

Climatic ChangeSystematic under- and overestimation of GHG reductions in renewable biomass systems (Climatic Change): This paper identifies a critical systematic error in greenhouse gas accounting in renewable biomass systems. While CO2 emissions from renewable biomass energy systems are generally considered to have a net impact of 0, no similar adjustment is made for carbon-based products of incomplete combustion, such as methane, in renewable systems. This results in an under- or overestimation of the impact of CH4 by 12.3% and CO by ∼478% in renewable systems. This error is propagated both in scientific studies and in carbon accounting policies.

Cookstove FigureBiochar—One way forward for soil carbon in offset mechanisms in Africa? (Environmental Science and Policy): The Kyoto Protocol’s Clean Development Mechanism (CDM) has had relatively little success in Africa due to a number of factors. Increases in agricultural soil carbon have strong benefits for soil health as well as potential for carbon sequestration, but such projects are currently excluded from the CDM and other offset mechanisms. Small-scale biochar systems with net emission reductions may hold a key for Africa to engage with the international offset mechanisms and open the door to soil carbon sequestration projects.