Fig. 1.

Cartoon illustrating some basics of the radionuclides ¹⁴C and ¹⁰Be in the Earth’s system. Both radionuclides are produced in a very similar way by nuclear reactions of cosmic ray particles with the atmospheric gases (3). After production, their fate is very different (system effects). ¹⁰Be attaches to aerosols and is transported within a few years to ground (34). ¹⁴C oxidizes to CO₂ and enters the global carbon cycle, exchanging between atmosphere, biosphere, and the oceans (4).