Sunday Times (London, UK) (pg. 10)  [Printer-friendly version]
September 23, 2007


By Jonathan Leake, Environment Editor

SCIENTISTS are considering a plan to combat climate change by dumping
millions of tons of iron into the ocean to alter its chemical make-up.

They believe the iron could act as a "fertiliser", promoting the
growth of tons of plankton that would soak up carbon dioxide from the
surrounding sea water. When the plankton died, their bodies would sink
into the deepest waters and sediments, where the carbon would be
locked up indefinitely.

The theory, known as "ocean fertilisation", has long caused
controversy among marine scientists, many of whom doubted that it
could work. This week leading researchers will meet at the Woods Hole
Oceanographic Institution in Massachusetts for a scientific conference
to discuss the idea.

The renewed interest follows experiments by Planktos, an American
firm, which seeded the Pacific ocean with 100 tons of iron particles,
creating a bloom of plankton earlier this year.

"Researchers have carried out a dozen other scientific trials and some
have shown interesting results," said Dr Ken Buesseler, a scientist at
Woods Hole.

Two years ago he led an expedition that dumped iron fertiliser into
parts of the Pacific and measured the impact on plankton. He found
that iron fertilisation did cause a surge in plankton, but there were
big variations in the amount that eventually got locked into the sea

In one area about half the plankton sank into the "twilight zone"
where their carbon was locked away, but in others this fell to just a
few per cent. "Ocean fertilisation needs a lot more research, but if
there is a chance that we could use it to cut atmospheric carbon we
have to look at it," said Buesseler.

Buesseler and Scott Doney, a colleague, are hosting the Woods Hole
conference which will bring leading scientists together with Planktos
and other commercial companies.

Russ George, chief executive of Planktos, said adding a single ton of
iron could remove as much as 100,000 tons of dissolved CO2 from the
oceans. "Historic increases in atmospheric carbon dioxide levels have
changed ocean chemistry and reduced iron availability. Replacing iron
artificially on a large scale could promote the growth of enough
plankton to completely combat climate change," George said.

Dr David Santillo, a senior scientist at the Greenpeace research
laboratories at Exeter University, said iron fertilisation was a
foolish idea. "There is no proof that the plankton blooms result in
carbon being locked into sediments," he said.

"Adding iron on such a scale will also damage natural ecosystems."

The Woods Hole conference comes amid increased anxiety over climate

Tomorrow Ban Ki-moon, the United Nations secretary-general, will
convene the largest meeting of world leaders on climate change at a UN
general assembly.

It will be followed by a meeting in Washington on Thursday and Friday,
convened by President George W Bush, for the leading economies to
discuss energy security and climate change.