The anthropocene-a potential stratigraphic definition based on black carbon, char, and soot records

Although the Anthropocene has been well recognized, whether or not it should be endowed the status of a new epoch or a formal unit of the geologic time scale is still debated due to the absence of a stratigraphic definition. In this paper, we review historical variations in wildfires based on the biomarkers of black carbon (BC) and its subtypes, including char and soot over the past 30 million years, to evaluate the possibility of using these as the basis for the stratigraphic definition of the Anthropocene. Wildfire and BC variations throughout the Cenozoic Era are continuously increasing and show some sharp changes in climatic boundary changes, suggesting that they might be useful in stratigraphic definitions. We also summarized glacial-interglacial variations during the Quaternary period from marine sediments, which suggests that soot with the regional and global dispersion may be a useful tool for epoch stratigraphic definitions. However, human-induced wildfires over the Holocene, based on the global charcoal combination data, present a decreasing trend in the past 2000 years, suggesting that their influence on soot emissions may be insignificant. Overwhelming changes occurred in the transition from biomass burning to fossil fuel combustion, leading to the emission of more soot. Although historical variations in soot are not globally uniform in the aftermath of the Industrial Revolution, there has been a global increase over the last hundred years. Thus, if the stratigraphic definition of the Anthropocene is not limited to a specific date, but encompasses a range of periods, soot can be utilized as part of a definition. We also suggest that soot, in conjunction with other markers, could be useful as part of the stratigraphic definition of the Anthropocene.