Adding nutrients, such as iron or nitrogen, or pumping nutrient-rich deep waters up into surface waters in the hope that the resulting bloom will provide long-term storage of carbon dioxide, should not be considered as a potential solution to climate change.

Experiments to date have shown that the amount of carbon actually exported to the deep ocean is small and highly uncertain.

Nevertheless, it continues to be touted as a simple solution to climate change.

possible ecological effects include shifts in plankton community structure that could dramatically alter food webs, creation of dead zones deprived of oxygen as the excess plant life decays, and harmful algal blooms.

atmospheric scientists are concerned that artificially-stimulated blooms could exacerbate climate change by increasing the production of nitrous oxide, a greenhouse gas far more potent than carbon dioxide.

All this makes ocean fertilisation a highly unfit candidate for carbon credits.