Is marine geo-engineering a solution to climate change?

IUCN website 9 Oct 08;

Climate change is destroying ecosystems and desolating communities dependent upon them. Should we now be seeking to reverse this trend through intentional large-scale manipulation of the marine environment?

Proposals are already being made to “geo-engineer” the oceans, for example, by stimulating phytoplankton blooms that may potentially fix carbon dioxide (CO2) and transfer it to the deep seabed, or by directly injecting CO2 into geological structures under the seafloor.

Interest in geo-engineering has lately been fuelled by several prize announcements to encourage a viable technology to remove greenhouse gases from the atmosphere and by the increasing carbon offsetting markets. The race is on to develop geo-engineering technology, but are we moving too quickly? And how much do we really know about the impacts of such actions?

"The concept of ocean fertilisation is morally indefensible as it relies on an assumed capacity of natural systems to assimilate and adapt to human-induced changes, rather than on actions which can be taken to avoid those changes, and therefore runs counter to fundamental principles of sustainability,” said David Santillo, Senior Scientist at Greenpeace during the debate moderated by David Shukman, Environment and Science Correspondent for BBC News, at the IUCN World Conservation Congress.

There are clear concerns about the potential effectiveness and impacts of some of these technologies, and attendant conflicts between technological, environmental and ethical perspectives.

At the moment, no intergovernmental body has a clear mandate to decide if large-scale manipulations of the environment are acceptable as a response to climate change. Nevertheless, proposals for large-scale marine geo-engineering projects continue to be developed and tested in our seas.

“In the past, oceans were more productive and may have sequestered more carbon,” said Margaret Leinen, Chief Scientist at Climos, at the workshop. “Stimulating plankton blooms to consume and sequester more carbon could assist in decreasing the CO2 concentration in the atmosphere until our global energy economy can make the transition to fewer emissions.”

The workshop presented the current state of knowledge of selected marine geo-engineering technologies and addressed their potential uses, abuses and ecological impacts.