Life goes on

What a relief: The BP oil spill won't wipe out the Gulf of Mexico food chain after all. Early in September U.S. government scientists released measurements showing that bacterial consumption of the oil hasn't created an aquatic "dead zone" as some had feared. Although the water oxygen level dropped 20 percent in the spill region, it remains high enough to support fish and apparently isn't decreasing. Some experts take the numbers as a vindication of the risky decision by BP and the government to pump 771,000 gallons of chemical dispersants deep underwater during the crisis.

The Gulf's recovery is progressing faster than many expected. Researchers in the field report green grass in onetime oil-blackened marshes. The FDA says Gulf seafood is safe to eat, and wildlife casualties have been low compared to the 1989 Exxon Valdez spill. (Only about 4 percent as many birds have died.)

Some scientists aren't celebrating, though. The discovery of underwater oil plumes and a layer of oil on the seafloor led critics to describe an August estimate that three-fourths of the oil was gone as "a fairy tale scenario." They say persistent oil lurking in the Gulf, even in widespread, microscopic amounts, could have a future effect on wildlife-by causing tumors in growing fish, for instance.

But even the pessimistic acknowledge the oil plumes are diffuse and continue to be broken down by microbes. The overall environmental effects "could have been a lot worse," opined Lisa DiPinto, head of the National Oceanic and Atmospheric Administration's marine debris division. By comparison, the Mississippi River produces a New Jersey-sized dead zone in the Gulf every year simply from Midwestern fertilizer runoff.

Melting mistake

The ice caps of Greenland and West Antarctica aren't melting as fast as previously believed, say researchers in the United States and the Netherlands. Satellites since 2002 have measured minute changes in the Earth's gravitational field, and scientists had used those changes to estimate that Greenland was losing 230 billion metric tons of ice each year. (West Antarctica was believed to be losing 132 billion metric tons-while the rest of the South Pole has seen increasing ice cover over the last few decades.)

But those original predictions miscalculated a rebound effect occurring in the Earth's crust: The crust is still contorting and expanding in relief from the weight of long-gone Ice Age glaciers. With that factor corrected, the new outlook has the ice caps "melting at approximately half the speed originally predicted," according to the researchers. That supports increasing evidence that the North Pole won't melt within this decade, as some have ominously predicted.

Bug diesel

Energy technology company Joule Unlimited received a patent for what it calls the first "single-step, continuous process" for converting sunlight, CO2, and water directly into diesel fuel using microbes. Its genetically modified bacterium produces hydrocarbons without the need for a feedstock, such as sugar.

Last year the Department of Energy gave away $23.8 million to researchers working on "direct solar fuels" like Joule's. The company boasts it will synthesize diesel in amounts three times greater per acre than corn ethanol by 2012-but it may have production hurdles to leap first.