text: The inventory of carbon-14 in Earth's biosphere is about 300 megacuries (11 EBq), of which most is in the oceans.
  The following inventory of carbon-14 has been given:
  * Global inventory: ~8500 PBq (about 50 t)
  ** Atmosphere: 140 PBq (840 kg)
  ** Terrestrial materials: the balance
  * From nuclear testing (until 1990): 220 PBq (1.3 t)