Title: "Acetylene in polar ice cores: a new tracer of paleo-fire emissions"
Abstract: The burning of wildfires, agricultural fires, and biofuels are major sources of climate-active atmospheric gases such as CO, CO2, methane, and various other hydrocarbons. Reconstructing the history of biomass burning emissions on centennial and millennial time scales has proven challenging. As a result, we know relatively little about the long term relationships between burning and climate or the impact of man on global fire emissions. In this talk, Antarctic and Greenland ice core records of atmospheric ethane and acetylene for the past 2 kyrs are presented. These are short-lived hydrocarbon gases whose atmospheric budgets are strongly influenced by burning emissions. The results show that 1) preindustrial burning rates were likely greater than modern, and 2) reconciling the emissions histories for methane, ethane, and acetylene in terms of a single burning history is more challenging than anticipated.