Book excerpt: Biomass burning profoundly affects atmospheric chemistry, the carbon cycle, and climate and may have done so for millions of years. Bringing together renowned experts from paleoecology, fire ecology, atmospheric chemistry, and organic chemistry, the volume elucidates the role of fire during global changes of the past and future. Topics covered include: the characterization of combustion products that occur in sediments, including char, soot/fly ash, and polycyclic aromatic hydrocarbons; the calibration of these constituents against atmospheric measurements from wildland and prescribed fire emissions; spatial and temporal patterns in combustion emissions at scales of individual burns to the globe.