Globalizing results from ocean in situ iron fertilization studies

Abstract

Despite the growing number of in situ iron fertilization experiments, the efficiency of such fertilization to sequester atmospheric CO2 remains largely unknown. For the first time, a global ocean biogeochemical model has been evaluated against those experiments and then used to estimate the effect of a long-term and large-scale iron addition on atmospheric CO2. The model reproduces the observed timing and amplitude in chlorophyll, the shift in ecosystem composition, and the pCO2 drawdown; it also proves to be of utility in interpreting the observations. However, a full ocean fertilization during 100 years results in a 33 μatm decrease in atmospheric CO2, that is 2 to 3 times smaller than found previously. Copyright 2006 by the American Geophysical Union.