Pumping iron into the ocean could help slow climate change

Pumping iron into the oceans could help to reduce global warming, according to a new study.

By Louise Gray, Environment Correspondent Last Updated: 8:48PM GMT 28 Jan 2009

The nutrient leads to algae blooms which help to suck up carbon dioxide from the atmosphere and take it to the sea-floor.
Scientists believe that by adding iron to vast areas of the ocean they may be able to take the greenhouse gas out of the atmosphere and therefore slow climate change.
The report, published in Nature, found that natural iron fertilisation from volcanic islands in the Southern Ocean increased algae blooms two to threefold and the quantity of carbon dispatched to the seabed 3,000 metres below by a similar amount.
The use of iron fertilisation of the oceans has been proposed alongside other forms of "geo-engineering" to stop global warming such as putting satellites into space to create a giant sunshade or covering the icecaps to prevent melting.
However it was difficult to clearly demonstrate how effective adding iron to the oceans would be in the long term and there is still an international ban on the proposal.
Professor Richard Lampitt, of the National Oceanography Centre in Southampton where the study was carried out, said: "There is potential for that although until we have completed good experiments it is impossible to say.
"There could be some unacceptable consequences for marine life and even the production of other greenhouse gases that are released back into the atmosphere by phytoplankton," he said.
"There have been about a dozen studies so far into iron fertilisation and although they increased blooms of phytoplankton none have been long-term enough to see how effective it was at taking carbon out of the game."