Iron Fertilization and Carbon Sequestration

Author:  Buttino Nicholas
Date:  November 2007

In September 2007, scientists from all over the world met at the Woods Hole Oceanographic Institution to discuss the viability of offsetting global warming by fertilizing parts of the ocean with iron.

The theory behind iron fertilization notes that in parts of the Southern Oceans (near Antarctica) the main nutrient that limits the growth of marine plants is iron. If humans add iron to these environments perhaps more plants would grow, and thereby take in more carbon. When these plants die the organic carbon material sinks to the bottom of the ocean, sequestering the carbon indefinitely.

Ken Buesseler, senior scientist of marine and geochemistry at Woods Hole, commented that the point of this conference was to get the scientific community talking. The results are still far from conclusive, but limited studies show that iron fertilization can increase algae growth 20-50%. Encouraging as this number sounds, Buesseler fears that little additional carbon sinks to the bottom. He said, "we know that iron added to certain places makes [algal] blooms, but we do not know how long or how much of that carbon remains sequestered."

The conference also discussed the ecological implications of iron fertilizing. Additionally, because the suitable locations lie in international waters, no clear body exists with the power to regulate iron fertilization or demand environmental impact studies

While the conference came to no definite conclusion, the important thing, according to Buesseler is to continue scientific research to investigate the possibility. He expressed concern about corporate enthusiasm for iron fertilization with much scientific uncertainty remains, and stressed that the future requires "partnership[s] between scientists and commercial ventures."

Written by Nicholas Buttino