PNNL

Abstract

Climate change is one of the most serious issues facing the world today. Increasing concentrations of carbon dioxide (CO2) and other long-lived greenhouse gases (GHGs) in the atmosphere continue to warm the planet and destabilize the climate. It has been estimated that the impact from this warming could cost the state $10 billion per year by 2020, and $16 billion per year by 2040. Long-term solutions to the climate problem likely will require that large quantities of CO2 be removed from the atmosphere. In fact, massive CO2 drawdowns from the atmosphere have occurred in earth’s recent past from events occurring in our hemisphere. Studies of those analogs provide insight into the potential magnitude for specific actions to drawdown significant CO2 from the atmosphere. One of these potential actions is the large-scale production of biochar from abundant woody biomass waste and its storage in soils, where it remains stable for hundreds to thousands of years. Moreover, for the carbon emission intensity of Washington’s fuel mix, biochar production from biomass is twice as effective in offsetting GHG emissions as complete biomass combustion of the same biomass. Washington State has large quantities of woody biomass that could be purposed for production of combined heat/power/biochar (CHPB) through existing biomass boilers. We propose to 1) evaluate the quantities of Washington wood waste biomass, 2) inventory existing boiler capacity and assess the technical merits and challenges to repurpose the boilers to CHPB, and 3) apply literature values and analog biochar examples to better quantify the extent of CO2 drawdown that could be achieved in Washington State over the next century using engineered biochar. This white paper explores the potential to replicate the historical drawdowns of atmospheric CO2. a topic the authors think should be part of current climate-change mitigation discussions.