Dear EarthTalk: Is it true that the BP oil leak is much more of an environmental threat than previous spills from tankers, and if so why?
—Nathan Gore, Pawtucket, RI
No one knows for sure how the ongoing oil catastrophe in the Gulf of Mexico will affect the deep sea ecosystem, but scientists are not optimistic. Oil from what is now considered the nation's second largest spill, 1989's Exxon Valdez mishap, slicked 11,000 square miles of ocean surface and 1,300 miles of pristine Alaskan coastline while killing hundreds of thousands of birds and marine mammals and untold numbers of fish and fish eggs. But the impacts of the ongoing Deepwater Horizon leak in the Gulf may be far worse given that much of the loose oil is actually in the water column, not on the surface. In fact, researchers from the National Oceanic and Atmospheric Administration (NOAA) recently detected huge deepwater plumes of dispersed oil up to 30 miles long, seven miles wide and hundreds of feet thick.
Why would an undersea spill be worse? One outcome could be the expansion in size and extension in time of a seasonal "dead zone" that already plagues the Gulf of Mexico as a result of industrial pollutants and agricultural run-off from the Mississippi River. While huge Gulf of Mexico algae blooms help to naturally clean up the Midwest's factory emissions and wasted fertilizer, such a process doesn't come without a cost to the ecosystem. Every spring, in a condition known as hypoxia, this fast growing algae depletes large sections of the Gulf's water column of the oxygen crucial for other life forms to survive there. The BP oil spill is likely to exacerbate this problem, as natural oil-eating microbes swarming over undersea oil plumes could cause or add to hypoxic conditions in otherwise teeming swaths of the Gulf.
According to NOAA researcher Samantha Joye, the undersea oil poses a direct threat to large marine wildlife, such as fish, sharks and cetaceans, and also to the tiny stuff, including zooplankton, shrimp, corals, crabs and worms. By endangering these latter populations, the foundation of the marine food chain, the oil could have chronic long-term effects on the wider Gulf ecosystem, including the industries—more shrimp and oysters come from the Gulf than anywhere else in the world—that rely on them.
Another worry is how the chemical dispersants being used to break up the undersea oil will impact the Gulf's ecosystems and inhabitants. The dispersant's ingredients are a trade secret closely held by the company that makes it, and therefore have not been vetted by marine biologists to determine their safety for use in such a large application. It also remains to be seen what impact the tiny oil droplets left in the dispersant's wake will have. It could actually be worse for the undersea environment to break the oil up into tiny droplets (which is done to try to make it easier for microbes to digest them).
Beyond all these undersea environmental effects, the oil is also starting to wash up into coastal wetlands already besieged by overdevelopment, pollution and the lingering effects of Hurricane Katrina. If there can be any silver lining to this catastrophe, it may be that it is the wake-up call we've needed to start moving more rapidly away from fossil fuels to a clean, renewable energy future. For starters, we can all begin to reduce our own oil consumption and opt for clean and green energy sources whenever possible.
Dear EarthTalk: Where does ethanol as an automobile fuel fit into the alternative energy mix? Is it better for the environment than gasoline?
—Donna Allgaier-Lamberti, Pullman, MI
Ethanol—a biofuel derived from corn and other feedstocks—is already playing a major role in helping to reduce emissions from many of the traditional gasoline-powered cars on the road today. According to the U.S. Department of Energy, nearly half of all the gasoline sold in the U.S. contains up to 10 percent ethanol, which not only boosts octane but also helps meet federally mandated air quality requirements. By promoting more complete fuel combustion, this small amount of ethanol mixed into gasoline reduces exhaust emissions of carbon monoxide—a regulated pollutant linked to smog, acid rain, global warming and other environmental problems—by as much as 30 percent compared with pure gasoline.
Also, a growing number of so-called "flex-fuel" vehicles now available can run on either straight unleaded gasoline or so-called E85, a mix of 85 percent ethanol and 15 percent gasoline. Ethanol proponents underscore emissions savings, cost stability (ethanol is distilled from domestically grown corn) and reduced reliance on (foreign) oil as benefits of more drivers filling up their tanks with E85 instead of gas.
But even though some eight million flex-fuel vehicles are now on U.S. roads, most of them are not near convenient ethanol refilling stations and are therefore mostly running on regular gasoline. (The U.S. Department of Energy website has a map-based listing of E85 refueling stations across the country—most are in the Midwest's "corn belt.") So while the capacity and perhaps demand for a cleaner burning fuel is there, supplies have not kept pace—some say because the federal government has subsidized ethanol producers only and not the distributors and retailers who get the product to customers.
But this may change. In May 2009 President Obama signed a Presidential Directive to advance research into biofuels like ethanol and expand their use. The resulting Biofuels Interagency Working Group is developing a plan to increase flex fuel vehicle use by making E85 and other biofuels more available.
While many environmental advocates view increasing ethanol use as a promising development (if drivers would actually fill up with it), others are not so sure. Cornell agriculture professor David Pimentel argues that producing ethanol actually creates a net energy loss. His research shows that a gallon of ethanol contains 77,000 BTUs of energy for engines to burn but requires 131,000 BTUs to process into usable fuel, not including additional BTUs burned from fossil fuel sources to power the farm equipment to grow the corn, and the barges, trains and trucks used to transport it to refineries and ultimately fueling stations.
Pimentel also says that powering a car for a single year on ethanol would require 11 acres of corn, which could alternatively feed at least seven people. If we step up our use of ethanol and begin putting our farmers" yields into gas tanks instead of on dinner tables, we could see a shortage of domestically grown food and higher prices at the grocery store. To address this problem, biofuels producers are researching alternative non-food feedstocks such as algae, corn stalks, wood chips and switchgrass, though they would still make use of arable land that could grow food for human consumption.
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