Specific molecular markers in ice cores provide large-scale patterns in biomass burning

International efforts to retrieve ice cores from both poles and every possible continent have resulted in a wealth of high-resolution climatic and environmental records. Methodological advances in measuring past atmospheric chemistry are revealing aerosols from both natural and anthropogenic biomass burning. Chemical markers in ice cores can measure past fire regimes including changes in spatial distribution, timing and fuel type (Conedera et al., 2009). Low-latitude ice cores primarily reflect regional fire and climate parameters, while polar ice cores reflect a global signal. The reconstruction of past wildfire occurrence through molecular markers in ice cores is a new field, one that requires further investigation; nonetheless, the global array of archived ice cores allows for future research into one of the least known aspects of the climate system. Fire activity has varied in the past in response to climate, vegetation change and human land use. Recent aerosol emissions are a combination of anthropogenic particle emissions (e.g., oils, soot, synthetics) and vegetation burning. Biomass burning causes carbon dioxide emissions equal to 50% of those from fossil-fuel combustion and so is also highly likely to influence future climate change. Here, we discuss four chemical groups that can be used as proxies for fire-history reconstruction from ice cores: (1) monosaccharide anhydrides (MA), (2) light carbolic acids, (3) polycyclic aromatic hydrocarbons (PAH), and (4) lignin burning products. Combining measurements of these four chemical groups can help determine the relative contributions of natural and anthropogenic emissions on regional and global scales.