Why dumping iron at sea could help the environment

A massive new study into the environment has revealed that dumping surplus iron into the...

11:59 23 July 2012

A massive new study into the environment has revealed that dumping surplus iron into the sea effectively buries carbon dioxide for centuries. 

 

The study showed that the algae which is attracted when iron filings are added dies before falling deep into the sea. 

 

Some critics believe that ideas like this which use technology to offset global warming (which fall under the term geoengineering) is transferring problems and creating new environmental side effects that we will only have to deal with later. 

 

However, Professor Victor Smetacek, at the Alfred Wegener Institute for Polar and Marine Research in Germany, who led the new research, was quoted in the Guardian as saying: "The time has come to differentiate: some geoengineering techniques are more dangerous than others. Doing nothing is probably the worst option."

 

Dave Reay, senior lecturer in carbon management at the University of Edinburgh, added: "This represents a whole new ball game in terms of iron fertilisation as a geoengineering technique. Maybe deliberate enhancement of carbon storage in the oceans has more legs than we thought but, as the scientists themselves acknowledge, it's still far too early to run with it."

 

To test their theory, Smetacek's team dumped seven tonnes of iron sulphate to the ocean near Antarctica, an area in which iron levels are extremely low. 

 

Because the nutrient was so low, a massive bloom of phytoplankton started growing within a week. This phytoplankton (mostly species of diatom) expired after after three weeks and began to sink with their weight pulling the carbon they had incorporated with them to the floor.

 

Due to the location chosen, the team could track what happened within the area and just outside of it as well to assess any possible environmental concerns. They concluded that over 50% of the bloom had indeed fallen to depths below 1,000m and that a "substantial portion was likely to have reached the sea floor" at 3,800m.

 

This in turn means that carbon is far more likely to be kept out of the atmosphere and from damaging the O-zone layer for centuries. 

 

Not all the pollution could be dumped; probably only around a tenth of it but it could be make all the difference. 

 

Michael Steinke, director of marine biology at the University of Essex, was also quoted by the Guardian expressing the problem of where to dump: "Will this open up the gates to large-scale geoengineering using ocean fertilisation? Likely not, since the logistics of finding the right spot for such experiments are difficult and costly."