Carbon is essential to life. The sixth stable element in the periodic table is what every living being is made out of—the foundation of a habitable and livable Earth. But how does carbon and its three isotopes impact our world today? We can trace its most prominent influence back 80 years ago, to the discovery of carbon’s long-lived radioisotope. Meet carbon-14—aka 14C. Radiocarbon is the rarest and most critical isotope to life on this planet in the past, present, and future.