Here's a very interesting project whose outcome could change the world! More than 20 tons of iron dust has been dumped into the water near the Galapagos Islands. The idea is to revive the ocean plankton that absorb huge amounts of carbon dioxide from the atmosphere, and then sink down into the depths of the ocean. Apart from the technical aspects, it is probably also an example of social entrepreneurship -- making profit by selling carbon credits. But there is also huge skepticism that this could have adverse effects on other ecological processes in the ocean, because so little is understood right now. The project has similarities with thoughts by Freeman Dyson http://www.edge.org/3rd_culture/dysonf07/dysonf07_index.html, where he talks about the regeneration of biomass on land to reduce carbon dioxide.