National Geographic: A giant experiment went awry at sea this month. Shrimplike animals devoured 159 square miles (300 square kilometers) of artificially stimulated algae meant to fight global warming–casting serious doubt on ocean fertilization as a climate-control tool. For years, scientists have proposed supercharging algae growth by dumping tons of iron into the ocean. Iron is a necessary element for algae photosynthesis–the process by which the plants convert sunlight into energy–but …