Hungry Plankton Scuttle "Iron Fertilization" Scheme
Climate scientists defeated in ocean experiment
Agence France-Presse, March 25, 2009
BERLIN
(AFP) - Indian and German scientists have said that a controversial
experiment has "dampened hopes" that dumping hundreds of tonnes of
dissolved iron in the Southern Ocean can lessen global warming.
The
experiment involved "fertilising" a 300-square-kilometre
(115-sqare-mile) area of ocean inside the core of an eddy -- an immense
rotating column of water -- with six tonnes of dissolved iron.
As
expected, this stimulated growth of tiny planktonic algae or
phytoplankton, which it was hoped would take out of the atmosphere
carbon dioxide, the principal greenhouse gas blamed for climate change,
and absorb it.
However,
the scientists from India's National Institute of Oceanography (NIO)
and Germany's Alfred Wegener Institute (AWI) did not count on these
phytoplankton being eaten by tiny crustacean zooplankton.
"The
cooperative project Lohafex has yielded new insights on how ocean
ecosystems function," an AWI statement published on Monday said.
"But
it has dampened hopes on the potential of the Southern Ocean to
sequester significant amounts of carbon dioxide (CO2) and thus mitigate
global warming."
Earlier
projects with iron fertilisation were more successful because they used
algae protected by hard shells that do not thrive in the Southern
Ocean, the AWI said.
The
team set sail from Cape Town on January 7 and spent an "ardous" two ad
half months conducting the experiments, buffetted by the treacherous
waves of the notorious "Roaring Forties" and twice having to escape
approaching storms.
Spicy
Indian curries at each meal "contributed to the good atmosphere"
however in an "exciting experience laced with the spirit of adventure
and haunted by uncertainty quite unlike other scientific cruises," the
AWI said.
The
experiment is one of several schemes collectively known as
geo-engineering which have been getting a closer hearing in recent
years in the absence of political progress to roll back the greenhouse
gas problem.
But
these projects have been heavily criticised by environmentalists for
failing to tackle the human behaviour that causes global warming and
for having unforeseen and potentially catastrophic consequences.
Other
geo-engineering ideas include sowing sulphur particles in the
stratosphere to reflect solar radiation and erecting mirrors in orbit
that would deflect sunrays and thus slightly cool the planet.
Copyright © 2009 AFP. All rights reserved.
