Dynamical limitations on the Antarctic iron fertilization strategy

Abstract

MARTIN et al. have proposed an ingenious means by which the rise in atmospheric CO₂ content generated by the burning of fossil fuels and deforestation might be partially compensated¹. The idea is that plant production in the nutrient-rich surface waters of the Antarctic could be stimulated by the addition of dissolved iron, thereby reducing the CO₂ partial pressure in these waters and allowing CO₂ to flow from the atmosphere into the Antarctic Ocean. We have used a box model calibrated with transient tracer data to examine the dynamical aspects of this proposal, and conclude that after 100 years of totally successful fertilization the CO₂ content of the atmosphere would be lowered by only 10±5% below what it would have been in the absence of fertilization. So if after 100 years the CO₂ content of the atmosphere were 500 fjiatm without fertilization, it would be between 425 and 475 µ atm with full fertilization. In other words, if our model calibration is correct, even if iron fertilization worked perfectly it would not significantly reduce the atmospheric CO₂ content.