ScienceInsider can report that a 10-week, 300-km² experiment to create a massive bloom of algae in the Southern Ocean will begin tomorrow. Furor over the potential environmental impact of the project had threatened to shut it down . The experiment, known as LOHAFEX, is the world's largest geoengineering project to date; scientists aboard the German research vessel Polarstern  (see photo) will create the bloom  in a patch of sea about halfway between the southern tip of South America and South Africa using 6 tons of iron, roughly three times more iron than previous oceanography experiments have used in catalyzing the growth of algae. The goal of the experiment, led by oceanographers Victor Smetacek of Germany and Wajih Naqvi of India, is to characterize how the ecosystem of the Southern Ocean, closely monitored for 2 months, would respond to such a massive dose of iron. Some scientists, including Smetacek, believe the technique could be an important way to sequester carbon into the ocean and even to restore harmed ocean ecosystems. But earlier this month, environmentalists attacked the experiment  as reckless.
After the German Environment Ministry came under pressure from environmental groups, the German Research Ministry ordered that the experiment be put on hold while independent scientific reviews by non-German scientists were done. So scientists with the British Antarctic Survey and the French oceanography institute IFREMER examined the experiment and issued an assessment of the possible environmental impacts of the project. (The patch of ocean that the scientists will fertilize is roughly one-millionth the size of the rest of the ocean.)
A spokesperson for the German Embassy in Washington, D.C., told ScienceInsider this afternoon that the experiment was deemed "acceptable” by the experts.The science ministry has found that "there are no scientific or legal concerns against LOHAFEX,” he said. ScienceInsider asked about the position of the German Environment Ministry, but the spokesperson said that the Research Ministry had jurisdiction over the experiment.