ABSTRACT
Today the concentration of 14C in the atmosphere and oceans is no longer in steady state; it has been hugely disturbed, first by the burning of fossil fuels (which contain little 14C and therefore dilute the 14C in the atmosphere), and second (and to a much larger extent) by pollution from nuclear testing. Thus 14C is now a transient tracer in ‘young5 water which has had recent contact with the surface. In old water, however, its concentration is still set by the steady-state considerations that applied until the industrial revolution.
