Dear EarthTalk: Is it better for the environment to burn synthetic oil or conventional oil in my car’s engine?
—David Bedell, New Canaan, CT
According to the Pennsylvania Department of Environmental Protection, 85 percent of the motor oil changed at home by do-it-yourselfers—about 9.5 million gallons a year in that state alone—ends up disposed of improperly in sewers, soil and trash. Multiply that by 50 states and it is easy to see how used motor oil might well be one of the largest sources of pollution affecting groundwater and our nation’s waterways. The implications are startling indeed, as one quart of oil can create a two-acre sized oil slick, and a gallon of oil can contaminate a million gallons of fresh water.
Conventional motor oils are derived from petroleum, whereas synthetic oils are replicas manufactured from chemicals that are really no kinder to the environment than petroleum. As such, conventional and synthetic motor oils are about equally guilty when it comes to how much pollution they create. But Ed Newman, Marketing Manager for AMSOIL Inc., which has been producing and selling synthetics since the 1970s, believes that the synthetics are environmentally superior for the simple reason that they last about three times as long as conventional oils before they have to be drained and replaced.
Additionally, Newman says that synthetics have lower volatility and therefore do not boil off or vaporize as quickly as petroleum motor oils. Synthetics lose from four to 10 percent of their mass in the high heat conditions of internal combustion engines, whereas petroleum-based oils lose up to 20 percent, he says. Economically, however, synthetics are more than three times the cost of petroleum oils, and whether or not they are worth the difference is the subject of frequent, inconclusive debate among auto enthusiasts.
But before deciding for yourself, consult your car’s owner’s manual regarding what the manufacturer recommends for your model. You can void your car’s warranty if the manufacturer requires one type of oil and you put in another. For instance, some Chevrolet Corvettes require synthetic motor oil only.
While synthetics seem to be the lesser of two evils for now, some promising new alternatives derived from vegetable products are coming of age. A pilot project at Purdue University, for example, has produced motor oil from canola crops that outperforms both traditional and synthetic oils with regard to both performance and production price, not to mention greatly lessened environmental impact. Despite the benefits, though, mass production of such bio-based oils would probably not be feasible, as it would require setting aside large amounts of agricultural land that could otherwise be used for food crops. But such oils may have a place as niche players as the worldwide market for petroleum products diversifies due to dwindling reserves and related geo-political tensions.
Dear EarthTalk: What are the effects of dumping man-made structures, like old cars and boats, into the sea for use as "artificial reefs?"
—Jed Gore, Stamford, CT
Coral reefs teeming with marine life are a magnet for fishermen and divers, but such underwater paradises exist only in tropical areas and certainly nowhere in the United States north of the Florida Keys. So in 1953, primarily to appease fishermen who thought such structures would attract fish, governments in some Southeast states began sinking car bodies, old boats, bridges and docks—even airplanes, ballistic missiles and defunct oil rigs—off the Atlantic coast and in the Gulf of Mexico. Since then, thousands of man-made materials have been sunk in the coastal waters of the region with the hope of attracting marine life.
Advocates of artificial reefs laud the structures" ability to enhance marine ecosystems by promoting underwater plant life and attracting the sea creatures that thrive on them. Artificial reefs, they say, help restore and revitalize otherwise flagging marine ecosystems decimated by years of overfishing and pollution. Opponents argue that they are a sham and are simply a way for oil companies and other business concerns to easily dump things that would otherwise be very costly to decommission properly.
Jack Sobel, director of Ecosystem Programs for the non-profit Ocean Conservancy, says, "Artificial reefs are no replacement for natural reefs or for proper fisheries management, and we don’t want people to view the oceans as a dumping ground for our wastes." Sobel argues that there is no scientific evidence that artificial reefs can sustain as much biodiversity as natural systems.
The Alabama Department of Conservation and Natural Resources, which sunk 100 obsolete combat tanks in 1994, would seem to agree. The agency now estimates that most of the artificial reefs they created in doing so will probably last no longer than 50 years. Sobel believes that such short-lived structures may threaten fragile marine ecosystems as they break up and scatter.
Because of such concerns—and because many marine ecosystems have been compromised by human activity and do need a jump-start—some innovative engineers have begun to design and deploy formations known as "reef balls": hollow, dome-shaped structures made of marine-friendly concrete and designed to imitate natural reef formations. The South Carolina Marine Artificial Reef Program, for example, has deployed more than a dozen different artificial reef designs throughout the state’s coastal waters since 1983.
The Georgia-based non-profit Reef Ball Foundation, which was created with the mission of restoring the world’s ocean ecosystems and protecting natural reef systems, has conducted similar projects in more than 50 countries around the world. The United Nations Development Program even named the Reef Ball Foundation one of its "2005 Environmental Laureates for Technology" for its work in helping increase marine biodiversity around the world.