Too early to say if iron seeding will slow global warming – scientists

Too early to say if iron seeding will slow global warming – scientists

Too early to say if iron seeding will slow global warming – scientists
mongabay.com
January 10, 2008

Schemes to use feed the ocean with iron as a way to enhance carbon sequestration from the atmosphere are premature and could be damaging to sea life and marine ecosystems, warns a letter published in the journal Science by an international group of scientists.

Ken Buesseler and colleagues say that while several small-scale ocean iron fertilization studies reveal the role iron plays in ocean ecosystems, the research was not designed to measure the use of iron as a strategy for carbon offsets to fight climate change. The authors say more research is needed to understand the long-term impact of iron fertilization, including its effects ecosystems.

“While we do envision the possibility of iron fertilization as an effective form of carbon offsetting, we believe larger scale experiments are needed to assess the efficiency of this method and to address possible side effects,” said Andrew Watson of the University of East Anglia. “There remain many unknowns and potential negative impacts.”

(A) Annual deposition fluxes of dissolved Fe to the ocean based on the Fan et al. two-step solubility process. (B) Ratio of fluxes shown in (A) and a constant 5% Fe solubility model. Image courtesy of SCIENCE.

The researchers propose internationally organized field studies on larger ocean areas for longer periods before iron fertilization strategies are adopted.

“This group feels it is premature to sell carbon offsets from the first generation of commercial-scale Ocean Iron Fertilization (OIF) experiments unless there is better demonstration that OIF effectively removes CO2, retains that carbon in the ocean for a quantifiable amount of time, and has acceptable and predictable environmental impacts,” concludes the letter.

Planktos, a U.S.-based firm, is using iron fertilization in an attempt to trigger a plankton bloom that will sequester carbon from the atmosphere. The company plans to sell carbon offsets based on the amount of carbon sequestered, but its plans have been widely condemned by environmental groups who say that scheme will do more harm than good and could put important ecosystems at risk. The U.S. government has also ruled that the experiment would violate ocean dumping laws.



Buesseler, K.O. et al. (2008) “Ocean Iron Fertilization—Moving Forward in a Sea of Uncertainty,” Science 11 January 2008