ScienceDaily— Leading marine scientists from across the world have issued a warning that it is too early to sell carbon offsets from ocean iron fertilisation.
Published last January in the journal Science, signatories include scientists from the US, Japan, Hawaii, New Zealand, The Netherlands, India, Germany and the UK. The UK is represented by Prof Andrew Watson of the University of East Anglia and Dr Richard Lampitt of Southampton University's National Oceanography Centre.
Prof Watson said: "While we do envision the possibility of iron fertilisation 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.
"There remain many unknowns and potential negative impacts."
Ocean iron fertilisation (OIF) is one of several marine-based methods proposed for mitigating rising atmospheric CO2. Research since 1993 has shown that releasing iron onto the ocean surface can stimulate the growth of plankton.
However, the efficiency with which OIF sequesters carbon from the atmosphere and retains it in the deep ocean is still uncertain and unintended ecological impacts are not yet fully understood.
Despite the scientific uncertainties, private companies are currently planning larger-scale iron releases to generate the sale of carbon credits.
The joint letter concludes: "This group feels it is premature to sell carbon offsets from the first generation of commercial-scale 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."
What is carbon offsetting?
Carbon offsetting is becoming an increasingly popular way for individuals and businesses to participate in solutions to global warming. The basic idea of a carbon offset is to figure out your personal contribution level to the global warming problem from such activities as driving, flying, or home energy use. This contribution is called a "carbon footprint." The term refers to carbon dioxide, the principal greenhouse gas. You can balance out your carbon footprint by buying carbon offsets. Your purchase funds reductions in greenhouse gas emissions through projects such as wind farms, which produce clean energy that displaces energy from fossil fuels. By funding these reductions in greenhouse gas emissions, you balance out, or offset, your own impact by an equivalent amount. Carbon offsets help you take personal responsibility for the environmental consequences of your activities. - from wikihow