Geoscience Reference
In-Depth Information
companies as a means of offsetting CO
2
emissions. A related climate change mitigation
technique is ocean carbon sequestration, which refers to the direct forcing of liquefied CO
2
into the ocean in order to store and isolate it. This technique is still experimental.
Ocean energy from offshore wind farms, wave-energy generating devices, and ocean
thermal vents offer potential for addressing climate change mitigation. Whilst technology
development to fully exploit ocean energy is still costly and in an experimental stage, the
International Energy Association estimates that total global installed capacity for ocean en-
ergy could be as high as 210 GW by 2050, as prices and access to ocean energy technolo-
gies are expected to fall.
Water generation from the ocean through a desalination process is now widespread
in many water-scarce regions but is becoming a mainstay in coastal areas, with huge de-
ficits in freshwater and groundwater pollution. The expansion of installed capacity for de-
salinated water has grown from about 8000 m
3
/d (in 1970) to about 32 Mm
3
/d (by 2001)
worldwide, and this is expected to grow exponentially as climate change and other human
activities reduce access to freshwater resources (Wangnick,
2002
).
Aquaculture has expanded dramatically in coastal areas due to increasing demand and
reduced supply of wild fish stocks. There are technological and financial challenges in ex-
panding aquaculture beyond coastal areas and exclusive economic zones, but with the ap-
propriatefinancialincentives andtechnologies itispossibleforaquacultureinthehighseas
to become a reality. This may include mobile cage operations such as the 'ocean drifter',
consisting of manned or autonomous cages capable of low-speed self-propulsion, operat-
