SEAWEED FARMING
AN INCREASING BODY OF RESEARCH IS DOCUMENTING THE POTENTIAL OF SEAWEED
FARMING TO COUNTER CLIMATE CHANGE AS DEFORESTATION DECIMATES RAINFORESTS AND
OTHER CRUCIAL CARBON SINKS.
Fast-growing oceanic jungles of kelp and other macroalgae
are highly efficient at storing carbon. Seaweed also ameliorates acidification,
deoxygenation, and other marine impacts of global warming that threaten the
biodiversity of the seas and the source of food and livelihoods for hundreds of
millions of people.
A new study for the first time quantifies the global
capacity of large-scale seaweed farming to offset terrestrial carbon emissions
and maps areas of the ocean suitable for macroalgae cultivation.
Seaweed is currently grown on a small scale for use in food,
medicines, and beauty products. The scientists, however, propose the
establishment of industrial-size farms to grow seaweed to maturity, harvest it,
and then sink it in the deep ocean where the captured carbon dioxide would be
entombed for hundreds to thousands of years.
They found that raising macroalgae in just 0.001 percent of
seaweed-growing waters worldwide and then burying it at sea could offset the
entire carbon emissions of the rapidly growing global aquaculture industry,
which supplies half of the world’s seafood. Altogether, 18.5 million square
miles of the ocean is suitable for seaweed cultivation. The technology doesn’t
yet exist to sequester seaweed in the deep ocean.
Indeed, other marine ecologists dub seaweed “charismatic
carbon” for the macroalgae’s Swiss army knife-like ability to address a variety
of environmental ills, in the ocean and on land.
COUNTER
Ø Beyond seaweed’s potential to counteract
acidification and deoxygenation, absorb excess nutrients and provide habitat
for marine life in at least 77 countries, seaweed can be processed into
biofuel.
Ø
And research has shown that adding seaweed to
livestock feed can reduce potent methane emissions from the burps of cows and
other grazing livestock—a significant source of global greenhouse gases—by as
much as 70 percent.
Ø
Seaweed can also be used as an agricultural soil
supplement, replacing petroleum-based fertilizers.
Ø
Primary Ocean’s strategy is to extract material
from seaweed that can be sold for agricultural use.
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Getting the international carbon credit bean
counters to accept seaweed as a legitimate source of greenhouse gas reduction
is one of the bigger challenges.
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Specifically we need carbon credit protocols
that can be used to claim carbon credits from seaweed aquaculture and also regulatory
environments that facilitate concessions and licenses for seaweed aquaculture.
Ø
China and other Asian nations that produce most
of the world’s farmed seaweed are expected to take the lead in establishing
macroalgae as a source of “blue carbon.”
