Ocean Fertilization to Cut CO2 Has Low Chance of Success, Study Says

The first comprehensive survey of plans to remove CO2 from the atmosphere by seeding the oceans with iron or other nutrients shows that even widespread fertilization would remove only modest amounts of CO2 from the air over the next century. The summary of existing studies said ocean fertilization also carries a risk of causing unintended long-term harm to marine ecosystems. Ocean fertilization involves dumping iron and other nutrients into the ocean to trigger the growth of phytoplankton, which consumes CO2 as it grows. But the summary, released at a conference on climate geoengineering schemes in California, said the risks of ocean fertilization probably far outweigh the rewards, as it is extremely difficult to assess the impact of the technique over wide swaths of ocean. “It’s vastly more complex than assessing carbon storage in a forest,” said lead author Doug Wallace of the IFM-GEOMAR Institute in Germany.