Ocean Fertilization

Ocean Fertilization

Depletion of other nutrientsIncreased phytoplankton productivity may deplete other essential nutrients and cause them to become limiting to phytoplankton growth. This in turn would cause a decline in the rate of Carbon Dioxide sequestration

Changes in elemental cyclingAs more nutrients are consumed, large quantities of them will enter into circulation, possibly overwhelming other aspects of the cycle. For example, there might be an increased cycling of nitrogen and evolution of N2O (a byproduct of denitrification) because of increased microbial activity in the deep ocean.

Cimate conernChange in mean oceanic temperatures

Changes in mean oceanic temperature could also affect the effectiveness of fertilization. The ocean-atmosphere interface is highly temperature dependent for absorbing Co2. A rise in mean ocean temperature might offset the effectiveness of fertilization because it would decrease the amount of CO2 that could be dissolved.

chemcial concern

Why we add iron to fertilize the ocean?

Ion fertilization consists of adding iron to the upper ocean to enhance thegrowth of phytoplankton and, as a consequence, boost photosynthesis to fix more CO2 andslow down global warming.

How can adding iron to the oceans slow global warming?

What is ocean fertilization

Iron acts as a fertilizer for many plants, and some, like the phytoplankton that form the base of the marine food web, need it to grow. Adding iron to the water stimulates phytoplankton growth, which in turn gobble up carbon dioxide through photosynthesis. The resulting decrease in carbon dioxide is supposed to help reduce temperatures since carbon dioxide is one of the main gases responsible for trapping heat on the earth's surface through the greenhouse effect.

Why ocean as the major CO2 container?

About 70% of the world’s surface is covered by oceans. Carbon dioxide is more present in theocean than in the atmosphere. The reasons for the large amount of CO 2 inthe oceans are its high solubility, the chemical reactionsit undergoes with water to give carbonate and bicarbonate ions, and biochemical reactions withmicro-organisms in the sea.Observations show that the concentration of DIC (dissolved inorganic carbon) increases from thesurface to deep ocean. The DIC is the sum of the concentrations of CO2, bicarbonate Observations show that the concentration of DIC (dissolved inorganic carbon) increases from the surface to deep ocean. The DIC is the sum of the concentrations of CO2, bicarbonate (HCO− 3 ) ) and carbonate (CO2− 3 ) ions: DIC = [CO2] + [HCO− 3 ] + [CO2− 3 ].Carbon dioxide in the ocean undergoes the following reactions: CO2 + H2O ⇔ H2CO3 ⇔ H + + HCO− 3 ⇔ 2H + + CO2− 3 ,which gives 88% of HCO− 3 , 10.9% of CO2− 3 and only 0.5% of CO2 for the total DIC .

Why change oceanic temperatures will affect he effectiveness of fertilization ?

Ocean fertilization or ocean nourishmen is a type of climate engineering based on the purposeful introduction of nutrients to the upper ocean to increase marine food production and to remove carbon dioxide from the atmosphere

The ocean-atmosphere interface is highly temperature dependent for absorbing Co2. A rise in mean ocean temperature might offset the effectiveness of fertilization because it would decrease the amount of CO2 that could be dissolved.