Discovered: The temperature at which malaria thrives; 140 billion cubic meters of gas goes up in flames every year; seafloor methane could rise; could iron boost fish populations?
Not too hot, not too cold, just right for spreading malaria. Scientists have long predicted that with rising temperatures, cases of malaria will become more common. But UC Santa Barbara's Kevin Lafferty and colleagues are revising theories about the temperature at which this "rampant" malaria transmission kicks in. It was previously thought that temperature would have to climb to an average of 31°C (88°F) before the epidemic-level spread of malaria kicks in. Lafferty thinks it could come at much lower temperatures, locating the malaria sweet-spot between 25°C and 28°C (77°F and 82°F). "Past models showed the whole world was going to light up with malaria," says Lafferty, who brought variables like insect physiology into his study. "It was quite terrifying." The new findings aren't good for places with mild climates (Europe, the U.S., and African highlands, for example), but actually bode well for more tropical regions that already suffer from widespread malaria. If the world heats up any more, they may be placed above the range at which malaria's spread falls off sharply. [New Scientist]
Can dumping iron into the ocean save salmon? It sounds like a far-fetched solution. But Russ George (chief scientist with the Haida Salmon Restoration Corp.) assures us: To save salmon, we need to unload 110 metric tons of iron dust, 91 metric tons of iron sulfate fertilizer, and 20 metric tons of iron oxide into the ocean. The plan is to recreate the fertilizing effects of a volcanic eruption, which have created conditions that allow plankton to thrive in the past. The plankton boom would trickle up the oceanic food chain, causing a growth in the salmon population. "There are three volcanic events in the last 100 years, and we had record sockeye salmon runs in those three volcanic dust events," George says. "That's pretty good data." But George's plan isn't without its skeptics. The University of British Columbia's phytoplankton researcher Maite Maldonado says of the region George has targeted, "There's not evidence that the region is iron-limited." And Canadian government scientists wrote in a recent paper on plankton surges in the wake of volcanic eruptions, "The 2010 phenomenal run ... may forever remain an enigma due to the lack of precise ecological and chemical data." George is known for previous big-idea environmental projects to abate CO2's rise through reforestation and ocean fertilization. [Scientific American]