Science Forums 2

[CraigD]

Originally Posted by Michaelangelica

Fascinating idea.
How would it be done in practice?

It was done in 1993 on a small, experimental scale, by a team lead by Richard Barber and Ken Johnson. They dumped about 500 kg of iron sulfate over a 65 km^2 patch of iron-poor ocean about 400 km southwest of the Galapagos Islands. By their measurements and estimates, this resulted in about 2,500,000 additional kg of carbon being sequestered by the phytoplankton in 2 weeks, the equivalent of about 100 full-grown redwoods.

What about sewerage? Would that be a good, cheap, plentiful solution?

I don’t think sewage contains much iron, so I don’t thinks so.

Fortunately, iron is a cheap, plentiful, easy to find mineral. About 5% of the Earth’s crust is iron.

Some scientists don’t think ocean iron seeding would work. Others worry that it’s viability could be used as an excuse to other greenhouse gas reduction measures. It’s certainly, IMHO, worth serious study.

A few articles on Barber and Johnson experiment: http://www.palomar.edu/oceanography/iron.htm; http://www.wired.com/wired/archive/8.11/ecohacking.html; http://news.nationalgeographic.com/n...arbonsink.html.

One problem with DDT(and similar) is that it floats on the top micron of the water and interferes with phytoplankton's reproductive capacity.(See DDT sould it be used (sic) Thread). Because of this (floating) you need very little DDT (etc) to do a lot of damage as the chemical is kept 'cheek by jowel' with the phytoplankton (Multiply area of sea surface by one micron then throw in trillions of tons of DDT type compounds==?)
I was amazed to read that phytoplankton are our major source of oxygen so you wonder what contribution DDT has, and is, making to global warming.(?)

I’d never considered this. I hope that this effect is confined to costal waters, and that these DDT films break up, poisoning only a small area of phytoplankton, before reaching the open ocean.