Only eight percent of U.S. homes use oil heat today. Natural gas is both cheaper and has lower carbon emissions than oil, though it is still a fossil fuel and its green-friendliness is overstated. Most eco-advocates would rather see a shift to truly renewable heating sources like geothermal or solar. (Thinkstock)

Natural gas has been a more affordable heat source than oil for Americans in recent years. The federal Energy Information Administration (EIA) reports that the average American homeowner will pay only about $732 to heat their home with gas this winter season (October 1 through March 31) versus a whopping $2,535 for oil heat. While the price of natural gas has remained relatively stable in the last few years, oil prices have been high and rising thanks in large part to continued unrest in Middle Eastern oil producing countries. Just two years ago the average winter home oil heating bill was $1,752.

While oil prices are likely to remain high and volatile in the foreseeable future, most energy analysts agree that pricing for natural gas, much of which is still derived domestically, is not expected to rise or fluctuate substantially in the U.S. any time soon. According to EIA economist and forecaster Neil Gamson, the U.S. already has a glut of natural gas and expects even more domestic production to come online soon as drillers are set to open up the Marcellus Shale in Pennsylvania and New York to more gas development.

Only about eight percent of U.S. homes are on oil heat today. Most are in the Northeastern U.S. and were built back in the day when oil was the cheapest way to keep toasty through the long winters. Many utilities have since put gas lines into neighborhoods that didn’t have them in the past, opening the door for homeowners to switch out old inefficient oil furnaces for more efficient gas units.

The federal government’s 30 percent tax credit (capped at $500) for upgrading to a high efficiency furnace expires at the end of 2011 but will likely be extended in one form or another into 2012. In the meantime, some states, municipalities and utilities offer their own incentives and low-interest loans on upgraded, high-efficiency furnaces. Check what’s available in your area via a zip code or map-based search online at the website of the Database of State Incentives for Renewables and Efficiency (DSIRE). Regardless of incentives, gas furnaces tend to cost less than their oil counterparts anyway, but installing one from scratch will incur an extra thousand dollars or two to run a gas line to it from the street. If natural gas continues to be substantially cheaper than oil, the fuel cost savings alone would pay back the up-front equipment and infrastructure investment within five years in most cases.

Environmentally speaking, gas has lower carbon emissions than oil, but hydraulic fracturing (“fracking”)—the highly controversial gas extraction method increasingly employed today (drillers inject water, sand and chemicals at high pressure underground to break through rock and access the natural gas)—takes a heavy toll on surrounding ecosystems and regional water quality. Most environmental advocates would rather see people transition to truly renewable heating sources like geothermal or solar. If you’re going to the cost and trouble of switching out an oil furnace for something new, a geothermal heat pump may cost more ($7,500 and up) than a new gas heating system but will save big bucks and emissions in the long run. For those in reliably sunny areas, a solar heating system will cost even more up front but can deliver similar long term economic and environmental benefits.

CONTACTS: EIA, www.eia.gov; DSIRE, www.dsireusa.org.

Dear EarthTalk: What, if anything, fills the empty space underground created by the extraction of billions of gallons of oil? Could oil drilling be one of the causes of increasing amounts of land settling and sinkholes in oil rich areas? Can it cause earthquakes? -- Linda Anderson, Sedona, AZ

The U.S. Geological Survey cites several cases throughout the 20th century which they say demonstrate how accelerated withdrawal of oil and gas from some reservoirs can lower land elevation, cause minor earthquakes and activate faults around oil fields (Media credit/Richard Masoner via Flickr)

The crude oil (and natural gas) we drill for the world over is, for the most part, stored in tiny pores within rock up to only about three miles deep in the Earth’s hugely dense crust. At such depths, the oil there is under fairly high pressure. When it is removed, other liquids—usually water—move in to take its place, equalizing the pressure in the process. Sometimes oil extractors pump water into one side of an oil field to push oil toward wells on the other side, and the water replaces the oil accordingly.

In cases where other liquids don’t move in, such as in the North Sea off The Netherlands, the porous rock layer that harbored the oil originally can collapse after extraction, causing slight amounts of land settling (known as “land subsidence”) in the rock layer surfaces above, but typically no more than a few tenths of an inch per year.

Here in the U.S., land subsidence induced by the large volume extraction of underground resources including oil and gas “is more common than most people realize,” according to the U.S. Geological Survey (USGS), a government agency which collects, monitors, analyzes and provides scientific understanding about natural resource conditions, issues and problems. Flat coastal plains and wetlands near sea level are most at risk from this potential side effect.

Excessive ground water pumping, not oil or gas extraction, is the single largest source of land subsidence, says the USGS, but the agency cites several cases throughout the 20th century which they say demonstrate how “accelerated withdrawal of oil, gas and associated water from shallow unconsolidated reservoirs could lower the land elevation, cause minor earthquakes, and activate faults [around oil fields].”

Subsidence around large, mature oil and gas fields that coincide with faults could add enough stress to trigger small, locally based earthquakes as far as two kilometers away from the offending wells. Most geologists agree, though, that it is unlikely that oil and gas extraction could contribute to or cause major earthquakes, which are generated at depths far deeper than would be practical to drill for oil or gas. The USGS does suggest, however, that the continued withdrawal of oil and gas and the associated decline in underground fluid pressure could even contribute to coastal sea level rises by lowering coastal land elevations.

As for sinkholes, modern oil wells tend to be much deeper than the depth where sinkholes typically can affect people. Nonetheless, in 1980 residents of the West Texas town of Wink awoke one morning to find a 370-foot wide, 110-foot deep sinkhole a couple of miles north of downtown. Geologists suspect the sinkhole formed as a result of historic (and by today’s standards outdated) oil production practices in the area whereby extractors pumped saltwater out from underneath the surface and left a void that the above layer of earth eventually collapsed into. A second, even bigger sinkhole opened up nearby in 2002.

CONTACT: U.S. Geological Survey, www.usgs.gov.

Dear EarthTalk: I’m considering going for a teeth whitening, but is this safe to do?  – Clara Reid, Kent, Washington

In the U.S., teeth whitening products are not regulated by the U.S. Food and Drug Administration, as they are not classified as drugs. As such, long term safety data doesn’t exist for them. But health experts warn that consumers should beware of the risks of using stronger varieties containing hydrogen peroxide. Hydrogen peroxide tends to be more effective (it essentially bleaches the tooth enamel), but it is a harsh chemical that can be poisonous if swallowed.

Europa, the official website of the European Union (EU), cites studies showing that bleaching teeth with hydrogen peroxide-based products can “harm the surface of the teeth, making the enamel more porous and leading to dents, scratches and loss of minerals.” Europa further warns that it’s important for people to keep their tooth enamel in good condition as it is “the protective, hard layer covering the softer dentine inside the tooth” and “does not regenerate.” The EU recommends people avoid tooth whitening products with hydrogen peroxide levels higher than a 1.5 percent concentration; most over-the-counter varieties come in at about a 0.5 percent concentration level. If the label on the product you are considering doesn’t indicate the concentration, it might be better to go with one that has a more complete ingredients listing.

Dentists can access teeth whitening solutions with higher concentrations of hydrogen peroxide than are available over-the-counter; as such a professional job in your dentist’s office will be more effective and last longer than the solutions you can take home from the drug store. And while higher concentrations of hydrogen peroxide might not be what you’re looking for, dentists can apply it in more targeted ways. If you do it yourself at home there is a greater chance you will expose your gums and other parts of your mouth to hydrogen peroxide or swallow more of it than you should.

As for maintaining that bright white look, whether you did it yourself or had it done professionally, your local drugstore or supermarket no doubt carries a wide selection of toothpastes that claim to whiten teeth. The ones which work the best contain—you guessed it!—hydrogen peroxide, which can be irritating if used day after day.

Fortunately for the health-minded home teeth whitener there are many less harsh varieties of these toothpastes now on the market. The website Skin Deep, a free online safety guide to cosmetics and personal care products published by the non-profit Environmental Working Group, lists Tom’s of Maine Natural Antiplaque Tartar Control Plus Whitening Toothpaste—which makes use of all-natural hydrated silica, not hydrogen peroxide, for whitening and stain removal—as one of the safest kinds of whitening toothpastes out there today. Burt’s Bees Natural Fluoride-Free Whitening Toothpaste and CloSYS Toothpaste for Teeth Whitening also get high marks from Skin Deep for their natural, non-toxic ingredients. While such products may not be “advanced” formulations from a leading packaged goods conglomerate, your teeth and body may thank you later.

CONTACTS: U.S. Food and Drug Administration, www.fda.gov; Europa, www.europa.eu; Greenfootsteps, www.greenfootsteps.com; Skin Deep, www.cosmeticsdatabase.com; Tom’s of Maine, www.tomsofmaine.com; Burt’s Bees, www.burtsbees.com; CloSYS, www.rowpar.com.

The National Oceanic and Atmospheric Administration recently detected huge deepwater plumes of dispersed oil up to 30 miles long, seven miles wide and hundreds of feet thick. Pictured here: Workers clean off an oil-soaked pelican at the Fort Jackson, Louisiana International Bird Rescue Research Center (Media credit/Lorna Baldwin, PBS NewsHour via Flickr)

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.

CONTACTS: Deepwater Horizon Response, www.deepwaterhorizonresponse.com; NOAA, www.noaa.gov.

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.

CONTACTS: U.S. Department of Energy, www.energy.gov; Argonne National Laboratory, www.anl.gov; E85 Fueling Station Locations, www.afdc.energy.gov/afdc/ethanol/ethanol_locations.html.

SEND YOUR ENVIRONMENTAL QUESTIONS TO: EarthTalk®, c/o E — The Environmental Magazine, P.O. Box 5098, Westport, CT 06881; earthtalk@emagazine.com. E is a nonprofit publication. Subscribe: www.emagazine.com/subscribe; Request a Free Trial Issue: www.emagazine.com/trial.

Dear EarthTalk: I heard that Walmart is having a bigger positive impact on the environment than any other U.S. institution. What are they doing along these lines?  -- R. Schlansker, Beaverton, OR

Walmart has indeed been working to clean up its image in recent years, and many environmentalists are pleased with the company’s commitment to reduce its massive carbon footprint. Many, however, view the company’s initiatives with skepticism, especially considering its overall impact on communities.

What’s noteworthy on the environmental front is not so much the significant energy and emissions the company is reducing at its stores and distribution centers and in its vehicles, but the ripple effect that its new carbon-cutting policies are having on the entire supply chain. This March, Walmart CEO Mike Duke announced a new goal of eliminating 20 million metric tons of greenhouse gases from its global supply chain—the equivalent of taking more than 3.8 million cars off the road for a year—by the end of 2015.

"To find these reductions, Walmart will be asking its estimated 100,000 suppliers to cut the amount of carbon they emit when they produce, package and ship their products," reports Dominique Browning of Environmental Defense Fund, which has been a key advisor to Walmart on green issues. Browning cites Walmart’s elimination of large laundry detergent bottles—since so much of them are water and energy-intensive to ship—in favor of concentrates sold in smaller bottles. As a result, concentrated laundry detergent is now the top seller at not only Walmart but at other stores, too. Walmart also convinced CD, DVD and video game makers to make their cases lighter to reduce transport carbon emissions, and they helped energy efficient compact fluorescent light bulb sales by spurring makers to refine their designs.

Many environmental and community advocates, however, consider Walmart’s pro-green efforts as too little too late or insignificant in relation to the company’s larger impact. Walmart Watch, a nonprofit group run by the Center for Community and Corporate Ethics, says the company has paid numerous fines over the last decade for violating air and water pollution rules, and that’s its green initiatives will easily be erased by its sheer growth which will mean more energy usage, more delivery truck trips and even more miles driven by consumers to get to Walmart stores that displaced smaller, more local ones.

Wake-Up Walmart, a project of the United Food and Commercial Workers International Union, says the company—which employs two million people in its 7,000+ stores—is also no friend to employees. Its average wage, says the group, is six percent below the Federal poverty level for a family of four and its move into urban areas, aside from destroying small businesses, often depresses other nearby wages where similar jobs otherwise pay as much as 18 percent more than Walmart. Further, says Wake-Up Walmart, the company pays $5,000 less yearly to full-time female employees than male ones, and its health plan is so poor that it forces many employees to rely on publicly assisted healthcare, at taxpayer expense.

Walmart Watch says the company has also been fiercely anti-union: "Labor law violations range from illegally firing workers who attempt to organize…to unlawful surveillance, threats and intimidation of associates who dare to speak out." Meanwhile, Walmart made a $14.3 billion profit in 2009, and its CEO earned $12.2 million in 2008, 587 times the annual income of an average full-time Walmart associate.

CONTACTS: Walmart, www.walmart.com, Environmental Defense Fund, www.edf.org; Walmart Watch, www.walmartwatch.com; Wake-Up Walmart, www.wakeupwalmart.com.

SEND YOUR ENVIRONMENTAL QUESTIONS TO: EarthTalk®, c/o E — The Environmental Magazine, P.O. Box 5098, Westport, CT 06881; earthtalk@emagazine.com. E is a nonprofit publication. Subscribe: www.emagazine.com/subscribe; Request a Free Trial Issue: www.emagazine.com/trial.

Dear EarthTalk: At a meeting of a local art association, an artist who paints in acrylics said that doing so is more eco-friendly than painting in oils.  I somehow doubt it. Aren’t acrylics petroleum based? And aren’t some oil paints made from natural materials? — Linda Reddington, via e-mail

Of course, there are no easy answers. There are environmental and health issues with both oil and acrylic art paints. The big downside of oil paints is the paint thinner required to clean them up. While some of the pigments in oil paint might be toxic or poisonous depending on color—reds, yellows, some blues and many whites are produced using potentially toxic heavy metals—the paint itself is typically made of food-grade linseed oil, which could hardly be more harmless to the environment (where it came from, after all). But oil paint is notoriously hard to clean up; getting those brushes, palettes and work areas clean requires the use of paint thinners, such as turpentine or mineral spirits, that are not only potentially toxic if used improperly but give off noxious odors and are highly flammable.

As for acrylic paints, they are water-based so clean-up is a breeze: Just wash it down the drain with some warm water, no paint thinner required. But acrylic paint is a petroleum-derived polymer, i.e. plastic. While cleaning it up might be easier than cleaning up oil paints, do we really want to be rinsing plastic down our drains? How good could this be for surrounding ecosystems? The other negative, of course, is that just buying them contributes to our reliance on petroleum.

So what’s a green painter to do? One option is to go for so-called water mixable oil paints that, according to manufacturers like Grumbacher, appear and behave in the same manner as traditional oil paints in every aspect except when it comes to clean-up—like acrylics, they thin and clean up with water instead of noxious chemicals. Water mixable oils are ideal for those sensitive to chemical fumes. Art supply chain Utrecht sells a wide variety of water mixable oil paints online and at its retail locations across the U.S.

If you must use traditional oil paints—many professional artists just prefer them for their thickness, color brilliance and other qualities—you can go with a brand that pays attention to the environmental impact of its products and operations. Oregon-based Gamblin Artists Colors Company uses only high-quality raw materials in its paints, avoiding preservatives that degrade the quality and release chemicals. Gamsol, the company’s paint thinner, uses mineral spirits that evaporate much more slowly than turpentine, which has a reputation for irritating breathing passages and inducing nausea. Every spring the company cleans its machinery, and instead of throwing the filter dust out, it recycles it and gives away tubes of the resulting gray paint free to artists through retail locations, and hosts a contest for art created with the unique color.

Another way to go would be truly all-natural. Berkeley, California-based GLOB crafts its paints from food-grade botanical extracts, so it’s even safe for kids aged three and older. Colored by real fruits, vegetables, flowers and spices, GLOB paints are all-natural, non-toxic, and free of chemicals, parabens, petroleum and synthetic preservatives. The palette is limited to just six colors, but creative artists should be able to mix to their heart’s content. The paints can be mail ordered, and they come in a dry powdered format, which saves weight, money and energy when shipped—users add water and start painting.

CONTACTS: Grumbacher, www.grumbacherart.com; Utrecht, www.utrechtart.com; Gamblin Artists Colors Company, www.gamblincolors.com; GLOB, www.globiton.com.

SEND YOUR ENVIRONMENTAL QUESTIONS TO: EarthTalk®, c/o E — The Environmental Magazine, P.O. Box 5098, Westport, CT 06881; earthtalk@emagazine.com. E is a nonprofit publication. Subscribe: www.emagazine.com/subscribe; Request a Free Trial Issue: www.emagazine.com/trial.

STATE COLLEGE, Pa. — AccuWeather.com — While the oil leak disaster in the Gulf of Mexico is bad enough, many people have been wondering what could happen if a hurricane were to slam into the region.

AccuWeather.com hurricane expert Joe Bastardi is concerned but multiple threats from storms throughout the season in the Gulf of Mexico.

Bastardi attributes heat rising over the tropical Atlantic to a collapsing El Ni±o pattern in the Pacific. In turn, the rising warm, moist air over the tropical Atlantic is forecast to unleash a top-10 hurricane season in the Atlantic Basin.

With 16 to 18 tropical storms and/or hurricanes expected, a significant number of these are bound to make their way into the Gulf of Mexico. Bastardi expects a little more than 1 out of 3 tropical storms and/or hurricanes to impact U.S. coastal waters this season.

The hurricane seasons of 1998, 2005 and 2008 had similarities to the expected pattern this season.

Some locations could be hit by more than one storm.

In this scenario, much of the central and western Gulf of Mexico could be one of several targets for potential multiple tropical storm and/or hurricane landfalls this year.

Depending on the approach of a tropical storm or hurricane, increasing winds and building, massive seas would first halt containment operations.

Rough seas would dislodge or destroy protective booms, rendering them useless as the storm draws closer.

Even a glancing blow from a hurricane passing to the west of the oil slick could be enough for winds and wave action to drive the goo nearby onshore, or to more distant fishing and recreation areas, perhaps in foreign waters.

During the age of sail, winds occasionally blew ships hundreds of miles off course. The wind could have the same effect on the oil slick.

Now, imagine several storms during the season doing the same thing.

There has been some speculation on the impact an oil slick might have on hurricane intensity, perhaps to the point of limiting the storm’s heat/moisture grabbing properties. However, high winds from the storm would probably mix the surface of the water/oil to the point, where it would not significantly have an impact.

Given the untimely nature of the weather, this could be a nasty summer and fall dealing with hurricanes in the Gulf, Atlantic and Caribbean, their natural effects and disasters alone, let alone managing the complicating oil slick disaster from the short term weather.

By AccuWeather.com Expert Senior Meteorologist Alex Sosnowski

The Lockerbie bomber may be free, but he isn’t breathing easy. In fact, he may soon meet the same fate as the 270 innocent men and women he was convicted of killing in 1988.

News reports out of Tripoli, Libya suggest al-Megrahi’s prostate cancer is worsening. Video footage of the 57-year-old convicted killer shows the man breathing through an oxygen mask, his head tilted to the side, his family members by his bedside.

In the background a reporter can be heard asking al-Megrahi a question. He appears too weak to respond.

Libyan Secretary of State for Foreign Affairs Mohammed Siala described al-Megrahi as a “dying man” according to AP.

Many questions have been raised regarding the seriousness of al-Megrahi’s condition. A video depicting him as an ailing man won’t put those theories to rest.

A London-based newspaper quoted al-Megrahi’s father as saying his son is not dying.

“I see he is improving day by day, and he is better than the day he returned” he told Asharq Al-Awssat newspaper.

Testing by Scottish officials is the only confirmation of al-Megrahi’s cancer, however now, to many, the testimony of Scottish officials is no longer sufficient because of the controversy surrounding the bomber’s release.

Many believe al-Megrahi’s release was made in order to facilitate an enormously lucrative oil deal with Libya. British Petroleum (BP) signed a $900 million oil search deal with Libya in 2007, but their progress has been repeatedly stalled by superfluous rules on equipment imports by Libyan officials.

British and Scottish authorities have both denied such a connection.

Quick thought.

I’m on vacation right now in England, currently staying across the University of Oxford, the alma mater of former UK Prime Minister Tony Blair. Blair is currently at the center of some controversy surrounding the reason behind the Lockerbie bomber’s recent release.

During a tour this morning I was reminded of an interesting fact. For those who don’t know, Blair, during his days at Oxford, co-founded, sang and played guitar for a band called the Ugly Rumours. Quite ironic that now he himself is the subject of some “ugly rumours” that may just prove to be true.

Those rumors, that Blair’s administration negotiated a deal with Libya to release Abdelbaset Ali Mohmed al-Megrahi in exchange for access to Libyan oil, are at this point not based on any hard factual evidence.

Blair and Britain have denied any such deal.

I’m sure Blair, while imitating Mick Jagger on stage at Oxford, never thought such an irony would arise.

End thought.

Dear EarthTalk: Don’t some scientists point to sunspots and solar wind as having more impact on climate change than human industrial activity? — David Noss, California, MD

Sunspots are storms on the sun’s surface that are marked by intense magnetic activity and play host to solar flares and hot gassy ejections from the sun’s corona. Scientists believe that the number of spots on the sun cycles over time, reaching a peak”"the so-called Solar Maximum”"every 11 years or so. Some studies indicate that sunspot activity overall has doubled in the last century. The apparent result down here on Earth is that the sun glows brighter by about 0.1 percent now than it did 100 years ago.

Solar wind, according to NASA’s Marshall Space Flight Center, consists of magnetized plasma flares and in some cases is linked to sunspots. It emanates from the sun and influences galactic rays that may in turn affect atmospheric phenomena on Earth, such as cloud cover. But scientists are the first to admit that they have a lot to learn about phenomena like sunspots and solar wind, some of which is visible to humans on Earth in the form of Aurora Borealis and other far flung interplanetary light shows.

Some skeptics of human-induced climate change blame global warming on natural variations in the sun’s output due to sunspots and/or solar wind. They say it’s no coincidence that an increase in sunspot activity and a run-up of global temperatures on Earth are happening concurrently, and view regulation of carbon emissions as folly with negative ramifications for our economy and tried-and-true energy infrastructure.

“[V]ariations in solar energy output have far more effect on Earth’s climate than soccer moms driving SUVs” Southwestern Law School professor Joerg Knipprath, writes in his “ËœToken Conservative’ blog. “A rational thinker would understand that, especially if he or she has some understanding of the limits of human influence. But the global warming boosters have this unbounded hubris that it is humans who control nature, and that human activity can terminally despoil the planet as well as cause its salvation.”

Many climate scientists agree that sunspots and solar wind could be playing a role in climate change, but the vast majority view it as very minimal and attribute Earth’s warming primarily to emissions from industrial activity”"and they have thousands of peer-reviewed studies available to back up that claim.

Peter Foukal of the Massachusetts-based firm Heliophysics, Inc., who has tracked sunspot intensities from different spots around the globe dating back four centuries, also concludes that such solar disturbances have little or no impact on global warming. Nevertheless, he adds, most up-to-date climate models”"including those used by the United Nations’ prestigious Intergovernmental Panel on Climate Change (IPCC)”"incorporate the effects of the sun’s variable degree of brightness in their overall calculations.

Ironically, the only way to really find out if phenomena like sunspots and solar wind are playing a larger role in climate change than most scientists now believe would be to significantly reduce our carbon emissions. Only in the absence of that potential driver will researchers be able to tell for sure how much impact natural influences have on the Earth’s climate.

CONTACTS:‚  NASA’s Marshall Space Flight Center, www.solarscience.msfc.nasa.gov; Token Conservative Blog, www.tokenconservative.com; IPCC, www.ipcc.ch.

Dear EarthTalk: Are the United States’ vast oil shale resources a potential source of energy?

– Larry LeDoux, Honolulu, HI

Oil shale is a fine-grained sedimentary rock that contains significant amounts of kerogen, a solid mixture of organic chemical compounds that can be converted into synthetic liquid fuel similar to oil, or into shale gas similar to petroleum-derived natural gas. Geologists believe there is more oil shale out there in the rocks of the world”"three‚ trillion barrels worth of fuel”"than there is oil in existing reserves globally.

Oil shale has been mined extensively in Brazil, China, Estonia, Germany, Israel and Russia, but up to two-thirds of the world’s supply lies in the Green River basin of the western United States, including parts of Wyoming, Utah and Colorado. To date, these American oil shale resources remain virtually untapped, but an 11th hour executive order by the Bush administration in 2008 put two million acres of Bureau of Land Management (BLM) land across Wyoming, Utah and Colorado up for lease to oil shale extractors.

Other nations with oil shale reserves have been mining them for decades for power generation and other uses, but American enthusiasm has run hot and cold, depending on oil prices. The U.S. was bullish on oil shale during the 1970′s oil shocks, but when gas prices fell again, so did the enthusiasm for oil shale.

American companies didn’t look into mining domestic oil shale again until 2003″"again, thanks to spiking oil prices. George W. Bush’s Energy Policy Act of 2005 officially opened federal lands to oil shale extraction. But then once again lowered oil prices, along with environmental concerns and growing enthusiasm for renewable energy sources left oil shale’s future in the U.S. again uncertain.

For their part, environmental groups are unequivocally against oil shale extraction. For one, extracting operations destroy affected landscapes, forcing plants and animals out, with regeneration unlikely for decades. Another big issue with oil shale extraction is water usage. The process requires as much as five barrels of water”"for dust control, cooling and other purposes”"for every barrel of shale oil produced.

Oil shale extraction is also very energy-intensive, and as such is no solution to our global warming woes. Researchers have found that a gallon of shale oil can emit as much as 50 percent more carbon dioxide than a gallon of conventional oil would over its given lifecycle from extraction to tailpipe.

Due to these concerns and others, 13 environmental groups, including the Wilderness Society, Sierra Club and Natural Resources Defense Council, teamed up in January 2009 to file suit against the federal government for opening up all that western U.S. land to oil shale development. The suit contends that the BLM failed to properly consider air quality and endangered species impacts in the region. The groups also contend that the development would require the construction of 10 new coal-fired power plants in order to get at and process the oil shale, significantly upping the carbon footprint of the entire region.

Green groups hope that the Obama administration will overturn Bush’s decision to lease development rights on the land, which is near three national parks in one of the least developed parts of the U.S.

CONTACTS: Bureau of Land Management, www.blm.gov; Wilderness Society, www.wilderness.org; Sierra Club, www.sierraclub.org; Natural Resources Defense Council, www.nrdc.org.

SEND YOUR ENVIRONMENTAL QUESTIONS TO: EarthTalk, P.O. Box 5098, Westport, CT 06881; earthtalk@emagazine.com. Read past columns at: www.emagazine.com/earthtalk/archives.php. EarthTalk is now a book! Details and order information at: www.emagazine.com/earthtalkbook.

• Two rivals claim victory in Israeli elections. (Obama worried about right wing government)

JERUSALEM “" Israel’s new coalition government “" whether led by hard-line Benjamin Netanyahu or his moderate rival Tzipi Livni “" is likely to take a tough line on two burning issues: Hamas and Iran.

As the two began courting potential coalition partners Wednesday, two scenarios took shape: a narrow alliance of hawks who would stall peacemaking with the Palestinians, or a broad power-sharing government that would give Israel a more moderate face and greater international support.

With only a few thousand votes by soldiers still to be counted, Livni’s Kadima Party had one more seat in parliament than Netanyahu’s Likud. But Netanyahu’s natural allies on the right have a clear majority of 65 in the 120-seat parliament, giving him the edge in forming a coalition.

President Shimon Peres will consult all 12 parties in the new parliament next week before choosing either Netanyahu or Livni to try to form a government “" a process likely to take weeks if not months.

• House and Senate reach compromise deal on the stimulus bill. Expect final passage this week.

WASHINGTON “" Moving with lightning speed, the Democratic-controlled Congress and White House agreed Wednesday on a compromise $790 billion economic stimulus bill designed to create millions of jobs in a nation reeling from recession. President Barack Obama could sign the measure within days.

“More than one-third of this bill is dedicated to providing tax relief for middle-class families, cutting taxes for 95 percent of American workers,” said Senate Majority Leader Harry Reid at a Capitol news conference where he was joined by moderates from both parties whose support is essential for the legislation’s final passage.

• No more off shore drilling.

WASHINGTON “" Interior Secretary Ken Salazar has rejected a Bush administration plan to open vast waters off the Pacific and Atlantic coasts to oil and gas drilling, promising “a new way forward” in offshore energy development including new wind projects.

Salazar at a news conference Tuesday criticized “the midnight timetable” for new oil and gas development on the country’s Outer Continental Shelf proposed by the Bush administration four days before President Barack Obama took office Jan. 20.

• Big change in press conference diction between this president and the last. Obama speaks at a 10th grade reading level, Bush at 7th.

• Finally, the homeless woman from Obama’s town hall gets a house.

Dear EarthTalk: What’s the story with LED light bulbs that are reputed to be even more energy-efficient than compact fluorescents? — Toby Eskridge, Little Rock, AR

Perhaps the ultimate “alternative to the alternative,” the LED (light-emitting diode) light bulb may well dethrone the compact fluorescent (CFL) as king of the green lighting choices. But it has a way to go yet in terms of both affordability and brightness.

LEDs have been used widely for decades in other applications-forming the numbers on digital clocks, lighting up watches and cell phones and, when used in clusters, illuminating traffic lights and forming the images on large outdoor television screens. Until recently LED lighting has been impractical to use for most other everyday applications because it is built around costly semiconductor technology. But the price of semiconductor materials has dropped in recent years, opening the door for some exciting changes in energy-efficient, green friendly lighting options.

According to HowStuffWorks.com, LED bulbs are lit solely by the movement of electrons. Unlike incandescents, they have no filament that will burn out; and unlike CFLs, they contain no mercury or other toxic substances. Proponents say LEDs can last some 60 times longer than incandescents and 10 times longer than CFLs. And unlike incandescents, which generate a lot of waste heat, LEDs don’t get especially hot and use a much higher percentage of electricity for directly generating light.

But as with early CFLs, LED bulbs are not known for their brightness. According to a January 2008 article in Science Daily, “Because of their structure and material, much of the light in standard LEDs becomes trapped, reducing the brightness of the light and making them unsuitable as the main lighting source in the home.” LED makers get around this problem in some applications by clustering many small LED bulbs together in a single casing to concentrate the light emitted. But such LED “bulbs” still don’t generate light much brighter than a 35-watt incandescent, much too little light for reading or other focused tasks.

If LEDs are going to replace incandescents and CFLs, manufacturers will have to make them brighter. EarthLED is lighting the way with its EvoLux and ZetaLux bulbs, which use multiple LEDs in a single casing to generate light. The EvoLux delivers light equal to that of a 100-watt incandescent, the company says. But the $80/bulb price tag may be tough to swallow. The ZetaLux, which retails for $49.99, delivers light equivalent to a 50- or 60-watt incandescent, will last 50,000 hours and costs only $2/yearly to run.

Other bulb makers are working on similar designs for high-powered LED bulbs, hoping that an increase in availability will help spur demand, which will in turn lower prices across the board. Until then, consumers can find LED bulbs suitable for secondary and mood lighting purposes in many hardware and big box stores. C. Crane’s 1.3-watt LED bulb, for example, generates as much light as a 15-watt incandescent bulb. Check your local hardware store for other options, as well as online vendors such as Best Home LED Lighting, Bulbster, SuperBrightLEDs.com and We Love LEDs.

CONTACTS: How Stuff Works, www.howstuffworks.com/led.htm; EarthLED, www.earthled.com; Best Home LED Lighting, www.besthomeledlighting.com; Bulbster, www.bulbster.com; SuperBrightLEDs.com, www.superbrightleds.com; We Love LEDs, www.weloveleds.com.

Dear EarthTalk: Used motor oil is a big contributor to the pollution in our waterways and drinking water. How can I make sure I am not contributing to this problem? — John Eckerle, Jupiter, FL

Motor oil leaked from individual vehicles-or outright dumped by homeowners and commercial garages-constitutes a significant chunk of storm water runoff, the fallen precipitation that runs off of roads and parking lots and inevitably finds its way into local water bodies.

These pollutants include not only leaked motor oil-which may contain toxic substances like lead, benzene, zinc or magnesium-but also fertilizers, insecticides, plastic debris, cigarette butts, paints, solvents, sediments and other hazardous waste. Topsoil and natural vegetation would ordinarily filter many of these pollutants out, but the impermeable pavement that covers much of the surface where these pollutants originate carries it right into storm drains and into streams, rivers, lakes and the ocean where it can poison marine life-which we might eat-as well as entire riparian or coastal ecosystems.

This pollution also finds its way into underground aquifers that supply our drinking water, so reducing it is a human health measure and could also save municipalities millions of dollars a year in drinking water treatment facilities and operational expenses.

While government agencies try to craft and implement development and zoning standards to help reduce storm water runoff problems caused by commercial and industrial entities, there is still much that individuals can do to reduce their impact as well. Indeed, upwards of 40 percent of oil pollution in the U.S. comes from the improper disposal of used motor oil by individuals.

The U.S. Environmental Protection Agency (EPA) recommends keeping on top of automotive maintenance to prevent and repair leaks, and disposing of used motor oil and other automotive fluids and batteries at designated drop-offs or recycling locations (consult Earth911.org to find one near you). Also, it is preferable to wash your car at a commercial car wash instead of in your driveway. By law, car washes must treat their wastewater before disposing of it.

Besides handling and discarding your motor oil and other automotive fluids responsibly, cutting back on or eliminating fertilizers and pesticides from your lawn or garden will also reduce your negative impact. Also, don’t over-water your lawn, as that can create extra run-off as well. And if you are embarking on a residential landscaping project, try to incorporate permeable pavement (which allows run-off through it into the soils below) as well as rain barrels to collect water, and rain gardens, grassy swales and driveway-side vegetative strips-all planted with region-appropriate native plants of course-to help filter contaminants out before they hit the storm sewers.

Taking these small everyday steps may seem like a hassle, but the benefits for the environment and human health are immeasurable.

CONTACTS: U.S. Environmental Protection Agency, www.epa.gov; Earth911, www.earth911.org.

GOT AN ENVIRONMENTAL QUESTION? Send it to: EarthTalk, c/o E/The Environmental Magazine, P.O. Box 5098, Westport, CT 06881; submit it at: www.emagazine.com/earthtalk/thisweek/, or e-mail: earthtalk@emagazine.com. Read past columns at: www.emagazine.com/earthtalk/archives.php

Dear EarthTalk: What is “community based tourism” and how does it purport to safeguard pristine places? -- Erin O’Neill, Tukwila, WA 

Community based tourism refers to situations in which local people-usually those that are poor or economically marginalized in very rural parts of the world-open up their homes and communities to visitors seeking sustainably achieved cultural, educational or recreational travel experiences. 

Under a community-based tourism arrangement, unique benefits accrue to both the traveler and the hosts: Travelers usually accustomed to chain hotels and beachfront resorts discover local habitats and wildlife and learn about traditional cultures and the economic realities of life in developing countries. And the host communities are able to generate lucrative revenues that can replace income previously earned from destructive resource extraction operations or other unsustainable forms of economic support. 

Locals earn income as land managers, entrepreneurs or food and service providers-and at least part of the tourist income is set aside for projects which provide benefits to the community as a whole. And just as important, says ResponsibleTravel.com, which promotes community based tourism in a partnership with Conservation International, the communities become “aware of the commercial and social value placed on their natural and cultural heritage through tourism,” thus fostering a commitment to resource conservation. 

Travelers indulging in a community based tourism trip might follow a local guide deep into his tribe’s forest to spot otherworldly wildlife, eat exotic regional delicacies around rough-hewn tables, watch and even take part in celebrations of local culture, and sleep on straw mats at the homes of local families.  

In many cases, local communities partner with private companies and nonprofits that provide money, marketing, clients, tourist accommodations and expertise for opening up lands to visitors. In 1997, eco-travel operator Rainforest Expeditions wanted international visitors to learn about threats to the rainforest. Natives in Peru’s Es©-eja community of Infierno wanted to generate income without destroying their rainforest home, central to their subsistence lifestyle. So the two joined forces and the resulting Posada Amazonas lodge to this day offers visitors an exotic way to learn about rainforest ecology directly from English-speaking Es©-eja staff, who in-turn earn a living sharing their local knowledge and traditions. 

Another example is the partnerships that the nonprofit Projeto Bagagem (Project Baggage) has forged with several Brazilian communities to bring in tourist dollars to support sustainable choices. A third of the cost of every Projeto Bagagem trip goes to the villagers and another third to a local nonprofit. Last year the group won a Seed Award from the United Nations and the non-profit World Conservation Union for its efforts to translate “the ideals of sustainable development into action on the ground.”  

Extreme poverty coupled with abundant natural resources makes the Amazon basin an ideal place for such programs to thrive, but community based tourism can be experienced anywhere. To find qualifying, pre-vetted trips that contribute to local economies all over the world, visit ResponsibleTravel.com. 

CONTACTS: ResponsibleTravel.com, www.responsibletravel.com; Rainforest Expeditions, www.perunature.com; Projeto Bagagem, www.projetobagagem.org. 

Dear EarthTalk: How often do I really need to change my car’s oil? Conventional wisdom has always put it at every 3,000 miles to prevent engine wear, but isn’t changing oil that frequently wasteful and unnecessary? Also, what is the “greenest” and longest-lasting oil I should use? – Vic Roberts, Lincoln, MA 

There is much debate in the automotive world over how often drivers of typical passenger cars or light trucks should change their oil. The quick-lube chains usually recommend it be done every three months or 3,000 miles, but many mechanics would tell you that such frequent changes are overkill. Indeed, most car owner’s manuals recommend changing out the oil less frequently, usually after 5,000 or 7,500 miles. 

According to the automotive website Edmunds.com, the answer depends more on driving patterns than anything else. Those who rarely drive more than 10 miles at a time (which doesn’t get the oil hot enough to boil off moisture condensation) or who start their car frequently when the oil isn’t hot (when most engine wear occurs) should change their oil more often-at least twice a year, even if that’s every 1,000 miles, according to Edmunds. But commuters who drive more than 20 miles a day on mostly flat freeway can go as far as their owner’s manual recommends, if not longer, between changes. As a car ages, more frequent changes might be in order, but that’s for a qualified mechanic to decide on a case-by-case basis. 

“The necessity of 3,000 mile oil changes is a myth that has been handed down for decades,” writes Austin Davis, proprietor of the website TrustMyMechanic.com. He says that the economics of the oil change industry demand pushing customers to get their oil changed more frequently-purportedly as “cheap insurance” against problems cropping up-whether they need it or not. One of the largest oil change chains, Jiffy Lube, for instance, is owned by Pennzoil-Quaker State, and as such has an incentive to sell as much of the company’s traditional petroleum-based oil as possible. 

One way to reduce trips to and money spent unnecessarily on quick-lube outlets is to switch to synthetic oils, which last longer and perform better than their traditional petroleum-based counterparts. Davis says that educated drivers should opt for longer lasting, better performing synthetic oils, which are “most likely good for 10,000 to 15,000 miles or six months” whether or not their manufacturers recommend more frequent changes or not. Some synthetic motor oils, like Amsoil, NEO and Red Line, to name a few, are created specifically to last 25,000 miles or one year before needing a change. 

While neither conventional nor synthetic motor oils are good for the environment if disposed of improperly or spilled, most environmentalists would opt for the latter since it lasts three or more times longer and thus reduces waste (or energy use if recycled). Researchers have been experimenting with producing greener motor oils-one pilot project out of Purdue University has produced high-quality, carbon-neutral motor oil from canola crops-but consumers should not expect to see such products on store or garage shelves anytime soon, as the costs of production are high and the availability of cropland is limited. But the very existence of such alternatives-no doubt more are in the offing-bodes well for the future as oil becomes more scarce and expensive. 

CONTACTS: Edmunds.com, www.edmunds.com; TrustMyMechanic.com, www.trustmymechanic.com. 

GOT AN ENVIRONMENTAL QUESTION? Send it to: EarthTalk, c/o E/The Environmental Magazine, P.O. Box 5098, Westport, CT 06881; submit it at: www.emagazine.com/earthtalk/thisweek/, or e-mail: earthtalk@emagazine.com. Read past columns at: www.emagazine.com/earthtalk/archives.php.