Nate Hagens describes 'fossil carbon' as the ancient, stored carbon that resides in the Earth’s crust, originating from biomass that underwent geological processes over millions of years, transforming into coal, oil, and natural gas. This term encapsulates not only the actual carbon atoms locked in these fuels but also the immense, concentrated energy they contain, which is the result of eons of solar energy captured by prehistoric plants and micro-organisms. Hagens emphasizes that when this fossil carbon is extracted and burned, it reintroduces carbon dioxide into the atmosphere, which significantly contributes to anthropogenic climate change. Thus, fossil carbon represents both an energy treasure and a profound environmental challenge, highlighting the intertwining of society's dependence on these finite resources and the pressing need for sustainable energy solutions.

See also: fossil fuel, fossil energy, fossil hydrocarbons, carbon pulse, climate change