The Sargasso Sea  

The Times has an article on the proposed use of sea weed as a carbon sink and as a source of biofuels. Like the various proposals for generating biodiesel from algae, this seems a much more practicable way of creating biofuels than sacrificing farmland (or rainforest).

Remember the names sargassum and Sostera marina: if a group of Japanese scientists is to be believed, the fate of humanity may rest on colossal floating islands of the stuff.

The team envisages 100 vast nets full of quick-growing seaweed, each measuring six miles by six miles, floating off the northeast coast of Japan.

The seaweed in each net, growing to a weight of 270,000 tonnes a year, will absorb prodigious quantities of greenhouse gases and convert them to oxygen before being harvested 12 months later as a rich source of biomass energy.

If a pilot version of the project indicates that the idea is viable, and sufficient funding can be found, the concept of fighting global warming through giant seaweed farms across the world’s oceans could be included in the upcoming revision to the Kyoto Protocol.

“It’s actually thanks to seaweed that we’re here at all,” Dr Notoya said. “When the world was young, it was the little blue-green algae and other seaweeds that, over the years, converted so much of the carbon dioxide in the air into oxygen and eventually pushed it up to the levels it is at today. Now that the balance is being thrown off, it’s time for the seaweed to come and help again.”

The most critical part of the plan is to then convert the seaweed into useful energy — a process that draws on technology produced by the Mitsubishi Research Institute. When blasted with superheated steam, seaweed discharges hydrogen and carbon monoxide gases that can be used to create a biofuel, which, in turn, discharges no extra carbon dioxide when burnt.