– Diane McMorris, Rockport, ME

There are a number of online marketing offers of kits that will convert your car to “run on water,” but these should be viewed skeptically. These kits, which attach to the car’s engine, use electrolysis to split the water (H₂O) into its component molecules—hydrogen and oxygen—and then inject the resulting hydrogen into the engine’s combustion process to power the car along with the gasoline. Doing this, they say, makes the gasoline burn cleaner and more completely, thus making the engine more efficient.

But experts say the energy equation on this type of system is not, in reality, efficient at all. For one, the electrolysis process uses energy, such as electricity in the home or the on-board car battery, to operate. By the laws of nature, then, the system uses more energy making hydrogen than the resulting hydrogen itself can supply, according to Dr. Fabio Chiara, research scientist in alternative combustion at the Center for Automotive Research at Ohio State University.

Moreover, Chiara says, the amount of greenhouse gases produced by the vehicle “would be much larger, because two combustion processes [gasoline and hydrogen] are involved.” Finally, there is a safety consideration for consumers who add these devices to their cars. “H₂ is a highly flammable and explosive gas,” he says, and would require special care in installation and use.

The electrolysis process could be viable in saving energy if a renewable, non-polluting energy source such as solar or wind could be harnessed to power it, although capturing enough of that energy source on board the car would be another hurdle.

Researchers today put more focus on using hydrogen to power fuel cells, which can replace internal combustion engines to power cars and emit only water from the tailpipe. And though hydrogen is combustible and can power an internal combustion engine, to use hydrogen in that way would squander its best potential: to power a fuel cell.

Hydrogen fuel cell cars are gaining traction, but commercialization of hydrogen fuel has not yet been accomplished. “The potential benefits of fuel cells are significant,” say researchers at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL). “[H]owever, many challenges must be overcome before fuel cell systems will be a competitive alternative for consumers.”

The state of California operates a “Hydrogen Highway” program that supports development of hydrogen fuel cell technology and infrastructure. And many companies are working on ways to produce, store and dispense hydrogen. Cars powered by fuel cells are in prototype stages now, nearing production.

While we all wait to see how that shakes out, the best choice today for high mileage and low emissions is still the gasoline/electric hybrid car.

CONTACTS: Center for Automotive Research, http://car.eng.ohio-state.edu; NREL, www.nrel.gov; California Hydrogen Highway, www.hydrogenhighway.ca.gov.

Dear EarthTalk: I’ve heard so much about using Borax for green housecleaning.  But if this mineral has to be mined, doesn’t that negate some of its “green-ness?” – Elsa, Lincoln, Nebraska

Mining for minerals such as boron (the key ingredient in the “Borax” we use for cleaning, pest control and other household tasks) is an activity that typically leaves behind a big environmental footprint. Mining degrades the local landscape and destroys wildlife habitat, while polluting both air and water. It also usually consumes large amounts of water, which can be taxing in already arid regions, such as the Mojave Desert, one of two regions of the world (along with parts of Turkey) with large boron deposits.

Typically, boron is extracted in open-pit mines by drilling, blasting, crushing and hauling—all activities fueled by petrochemicals. The refining process then uses a significant amount of water. Finally, the waste product—known in the industry as “tailings”—is deposited in man-made ponds where further refining is done before the water is then discharged into the local watershed.

The mining industry has long been criticized as an environmental baddie, but the leading company that mines Borax, Rio Tinto, has actually been given high marks for environmental stewardship. Jared Diamond’s 2005 book, “Collapse: How Societies Choose to Fail or Succeed” called the British mining giant the exception in its industry. Due to “a strongly supportive CEO and British stockholders,” he wrote, the company moved forward with the 2002 environmental recommendations of the mining industry’s Mining Minerals and Sustainable Development project that were for the most part ignored by the rest of the industry. “Rio Tinto foresaw business advantages to being seen as an industry leader in social responsibility,” said Diamond. “Its Borax mine in Death Valley, California is now perhaps the most cleanly operated mine in the U.S.”

Boron, oxygen and sodium make up sodium tetraborate, which is sold as “20 Mule Team Borax” (the name comes from the teams of 18 mules and two horses that would haul large wagons of processed borax from mines in the late 1800s to the nearest railroad spur). The powdered detergent is considered a least-toxic recipe as a natural disinfectant and household cleaner. Beyond cleaning formulations, boron is also used in a wide variety of other products, including the manufacture of fiberglass and Pyrex.

Pest control is another use. One boron compound is used to treat wood to prevent fungal decay and repel carpenter ants, roaches and termites. Boric acid is included on the national list of allowed substances for structural pest control in organic food production (as long as there is no direct contact with food or crops). The U.S. Environmental Protection Agency has determined that pesticide products containing boric acid and its salts are of low toxicity. (However, ingesting it or applying large amounts to the skin can cause acute poisoning, so parents should be vigilant about where they store and use products containing Borax.)

Emerging uses of boron, and new ways to recycle its waste, may make this mineral even more valuable. A Turkish researcher notes that borax waste added to red bricks and cement products increases strength and lifespan. And at the National Boron Research Institute in Turkey, it is being studied as an element to produce fuel cells and to aid in cancer treatment.

CONTACTS: Rio Tinto, www.riotinto.com, U.S. Environmental Protection Agency, www.epa.gov; Turkey’s National Boron Research Institute, www.boren.gov.tr/en.

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.

According to marine scientists, the world’s coral reefs—those underwater repositories for biodiversity that play host to some 25 percent of all marine life—are in big trouble as a result of global warming. Data collected by the international environmental group WWF (formerly World Wildlife Fund) show that 20 percent of the world’s coral reefs have been effectively destroyed and show no immediate sign of recovery, while about 50 percent of remaining reefs are under imminent or long-term threat of collapse.

Most scientists now agree that global warming is not a natural phenomenon but a direct result of the continual release of excessive amounts of CO2 and other “greenhouse” gases into the atmosphere by human industrial and transportation activity. And the small but prolonged rises in ocean temperature that result cause coral colonies to expel the symbiotic food-producing algae that sustain them. This process is called “bleaching,” because it turns the reefs white as they die.

But researchers working with the Coral Reef Alliance have found that while coral reefs do store CO2 as part of photosynthesis, they tend to release most of it back into the ocean (so they are not what are known as “carbon sinks”). As such, the release of CO2 from dying coral reefs is not a major concern.

Of course, the ocean itself is a large carbon sink, storing about a quarter of what would otherwise end up in the atmosphere. Landmasses (and their plants) soak up another quarter of all the CO2 emanating from the Earth’s surface, while the rest rises up into the atmosphere where it can wreak havoc with our climate.

Recent findings indicate that the Antarctic Ocean is getting less efficient at storing CO2, and this raises serious questions about the ability of our oceans to handle everything we throw at them. The study’s authors fear that “such weakening of one of the Earth’s major carbon dioxide sinks will lead to higher levels of atmospheric carbon dioxide in the long-term.”

Not everyone is forecasting gloom and doom. Some Australian researchers believe that coral reefs around the world could expand in size by up to a third due to increased ocean warming. “Our finding stands in stark contrast to previous predictions that coral reef growth will suffer large, potentially catastrophic, decreases in the future,” says University of New South Wales oceanographer Ben McNeil, who led the controversial 2004 study that was published in the peer-reviewed scientific journal, Geophysical Research Letters. “Our analysis suggests that ocean warming will foster considerably faster future rates of coral reef growth that will eventually exceed pre-industrial rates by as much as 35 per cent by 2100,” he adds.

In spite of such theories, the majority of marine scientists remain pessimistic about the future of coral reefs in a warmer world. One can only hope that the optimists are right.

CONTACTS: WWF, www.panda.org; Coral Reef Alliance, www.coralreefalliance.org; “Coral reefs may grow with global warming,” New Scientist, www.newscientist.com/article/dn6763.html.

Dear EarthTalk: Short of buying a new hybrid or other “green” car, are there ways I can make my existing vehicle more eco-friendly? I bought my car recently and am not quite ready to give it up. – Bettie Hilliker, Lansing, MI

Choice of vehicle may well be the biggest factor in determining the environmental impact of your automobile-based travels. But a considerable amount of energy is used—and pollutants emitted—in the production of any new vehicle, including hybrids and other more fuel-efficient options. As a result, many environmentalists believe that practicing good driving habits and performing adequate maintenance on an older car are probably better options for the environment than causing the production of a new vehicle.

According to the website GreenerCars.org, there are many ways to green up one’s driving habits. Obeying speed limits, utilizing cruise control and avoiding jackrabbit starts will maximize fuel economy and minimize tailpipe emissions while also preventing unnecessary wear-and-tear. Staying off roads during rush hours is also advisable, as stop-and-go driving burns excess gasoline and promotes smog. Opening vents and windows to cool off instead of using the air conditioner, an inherently inefficient appliance that consumes more fuel and leads to more emissions, is also good advice.

Drivers can also help minimize their environmental impact by keeping their cars well maintained. According to GreenerCars.org, getting regular tune-ups—where a qualified mechanic changes fluids and checks for and corrects problems such as worn spark plugs, under inflated tires, dragging brakes, misaligned wheels and clogged filters—can significantly improve fuel economy and minimize harmful emissions. GreenerCars.org also recommends seeking out low-rolling-resistance (LRR) replacement tires, which are specifically designed to improve a vehicle’s fuel economy, when the original ones wear out.

Beyond regular maintenance, a handful of small companies now sell green-friendly fuel additives that purport to increase fuel efficiency while reducing emissions. Such products—including Bluestar Environmental’s Omstar D-1280X gas additive and Suntec Bio-Energy’s diesel additive—are normally targeted at fleets of vehicles, but individuals are free to use them as well. Owners beware, though: Use of such products could invalidate automakers’ warranties, so read the fine print in your owner’s manual before pouring anything out-of-the-ordinary into your fuel tank.

Of course, getting out of your car altogether—or most of the time—is a far greener choice than driving even a well-maintained new or old car conscientiously. Some employers now offer federally-subsidized “commuter choice” incentives whereby workers can derive financial benefits by telecommuting (working from home), or by walking, biking, using public transit or carpooling to and from the office.

Another option is to join a car sharing service like Zipcar or Flexcar, whereby you pay a modest monthly membership fee and can then rent cars parked nearby by the hour only when needed. The companies operate on both U.S. coasts, as well as in major Midwestern and Canadian cities.

CONTACTS: GreenerCars.org “Green Driving Tips,” www.greenercars.org/drivingtips.htm; Bluestar Environmental, www.ablustar.com ; Suntec Bio-Energy, www.suntecbioenergy.com; Zipcar, www.zipcar.com; Flexcar, www.flexcar.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.