Rainforests are also home to some 50 percent of the world's species, Butler reports, "making them an extensive library of biological and genetic resources." Environmentalists also point out that a quarter of our modern pharmaceuticals are derived from rainforest ingredients, but less than one percent of the trees and plants in the tropics have been tested for curative properties. Sadly, then, we don't really know the true value of what we're losing as we slash, burn, and plant over what was once a treasure trove of biodiversity.
According to the United Nations' Food and Agriculture Organization (FAO), overall tropical deforestation rates this decade are 8.5 percent higher than during the 1990s. While this figure pertains to all forests in the world's tropics, researchers believe the loss of primary tropical rainforest—the wildest and most diverse swaths—has increased by as much as 25 percent since the 1990s.
Despite increased public awareness of the importance of tropical rainforests, deforestation rates are actually on the rise, mostly due to activities such as commercial logging, agriculture, cattle ranching, dam-building and mining, but also due to subsistence agriculture and collection of fuel wood. Indeed, as long as commercial interests are allowed access to these economically depressed areas of the world, and as long as populations of poor rural people continue to expand, tropical rainforests will continue to fall.
Some scientists see light at the end of the tunnel. Joseph Wright of the Panama-based Smithsonian Tropical Research Institute says the tropics now have more protected land than in recent history, and believes that large areas of tropical forest will remain intact through 2030 and beyond: "We believe that the area covered by tropical forest will never fall to the exceedingly low levels that are often predicted and that extinction will threaten a smaller proportion of tropical forest species than previously predicted."
Only time will tell whether Wright's optimistic predictions ring true, or whether a more doomsday scenario will play out. To stay informed and be part of the solution, stay tuned to the websites of Rainforest Action Network, Rainforest Alliance, the Rainforest Site and, of course, Mongabay.com.
CONTACTS: Mongabay, www.mongabay.com; Rainforest Alliance, www.rainforestalliance.org; Rainforest Action Network, www.ran.org; Rainforest Site, www.rainforestsite.com; FAO, www.fao.org.
Dear EarthTalk: I recently saw a reference to "Enertia houses" that require little in the way of external sources for heating or cooling. Do you have any information on this housing design?
-- Alan Marshfield, via e-mail
Enertia is a brand name for homes designed and sold in kits by North Carolina-based Enertia Building Systems (EBS). The idea essentially marries the concepts of geothermal and passive solar heating/cooling into what amounts to a highly energy efficient hybrid system. Architectural inventor Michael Sykes coined the term "Enertia" in the 1980s to describe the innovative homes he was designing that would store solar and geothermal energy and make use of it for most if not all heating and cooling needs.
Under such a system, solid wood walls replace siding, framing, insulation and paneling, while an air flow channel—or "envelope"—runs around the building inside the walls, creating what Sykes terms a miniature biosphere. Inside the envelope, solar heated air circulates, pumping and boosting geothermal energy from beneath the house and storing it within the wood mass of the walls, where it is doled out gradually.
By harnessing the properties of thermal inertia—the ability of materials to store heat and give it off slowly—an "Enertia" house maintains a relatively fixed and comfortable temperature throughout the warmer day (when solar heat is collected and stored) and cooler night (when the wood walls give off heat to keep things toasty as the mercury dips).
The heart of the system is a south-facing sun space within the envelope that is dominated by windows and which therefore soaks up lots of solar energy, filling the house's wood walls with thermal energy that in turn radiates into the primary living space. The entire house functions like an electric heat pump—moving warm and cool air around to accommodate the comfort needs of the occupants. It works even throughout the seasonal changes of the year—with minimal to no fossil fuels consumed or pollution generated.
In one Enertia house in North Carolina, the only power bill the owners typically pay is $35/month for electricity. They also have a back-up in-floor radiant heating system powered by natural gas for long cloudy stretches or unusually cold weather. Gas bills for heat typically total $150 for the year, meaning the owners' total annual outlay for heating, cooling and electricity is less than $600—some $1,000 less than traditional homes in the same zip code are paying, according to data from the U.S. Department of Energy.
EBS markets several different designs for its Enertia houses, but all share the basic premise of primary interior living space heated and cooled by air channeled in from a south-facing "buffer zone" envelope and from below grade. Smaller houses in the line top out at about 2,000 square feet over two floors of living space, while larger ones encompass some 4,000 square feet of living space over three floors. Depending on the model, you could spend anywhere from $66,000 to $292,000 for a complete plan and building materials kit. The rest—including the selection and cost of the land and the labor to build the house—is up to you.
CONTACTS: Enertia Building Systems, www.enertia.com.
Dear EarthTalk: How can I make good use of the rainwater that runs down my roof and into my gutters?
-- Brian Smith, Nashua, N.H.
For most of us, the rain that falls on our roof runs off into the ground or the sewer system. But if you're motivated to save a little water and re-distribute it on your lawns or plants—or even use it for laundry, dishes or other interior needs—collecting rainwater from your gutters' downspouts is a no-brainer.
If it's allowed in your state, that is. Utah and parts of Washington State have antiquated but nonetheless tough laws banning anyone but owners of water rights from collecting rainwater flowing off privately owned rooftops. Such laws are rarely enforced, however, and one in Colorado was recently overturned.
According to John C. Davis, writing in E – The Environmental Magazine, just about any homeowner can collect rainwater, given that the roof and gutters do most of the work. And since an inch of rain falling on a 2,000-square-foot roof produces some 1,200 gallons of runoff, one can harvest enough to supply all the water needs of a family of four for about two weeks. Of course, most of us would only use rainwater to irrigate our lawn or garden, and there should be plenty to go around for doing that in all but the most drought stricken areas.
Plants and grass actually do better when fed rainwater instead of tap water, which is usually treated with softeners that actually inhibit plant growth. And, reports Davis, the lack of minerals in rainwater actually makes it more effective than tap water for shampooing or doing dishes. Using rainwater for plumbing uses can also extend the life of pipes and water heaters, since the salts added to tap water facilitate corrosion. Homeowners should set up a water purification system if they do plan to use rainwater for interior needs.
Beyond the benefits to individual homeowners, rainwater harvesting can also be good for the local community, as it reduces the erosion, flooding and pollution runoff associated with heavy rainfall, and lessens reliance on public water supplies, alleviating some of the burden on utilities. Given these benefits, some states, including even drought-prone Texas, subsidize residential rainwater collection systems.
Many varieties of rain barrel systems, starting at just $100, are available for home installation. A typical set-up is simply a rain barrel positioned under a gutter's downspout. "The barrel is typically fitted with a spigot at its base to fill a watering can or attach a soaker hose (which bleeds out water all along its length, providing effortless drip irrigation), and a filter or screen at its top to prevent a buildup of leaves and other debris," writes Davis. According to the U.S. Environmental Protection Agency, a single 100 gallon rain barrel can save up to 1,300 gallons of utility-provided water during the high demand summer months.
Handy homeowners can make their own water harvesting systems, but buying one pre-made is a lot easier. Most nurseries and garden centers offer a range of choices (as well as advice), but websites such as Aquabarrel, Clean Air Gardening and Rainxchange make it easy to order a system online.
CONTACTS: Aquabarrel, www.aquabarrel.com, Clean Air Gardening, www.cleanairgardening.com; Rainxchange, www.rainxchange.com.
Dear EarthTalk: I heard that goats are being used to prevent some of those catastrophic fires that seem to happen increasingly. What's the story with that?
-- Ali B., New Canaan, Conn.
As wildfires consume parts of California larger than some smaller states, everyone is talking about how we can prevent such disasters from getting going in the first place. One novel approach is to enlist goats. Not as firefighters—although their surefootedness and determination would probably serve them well in such situations—but as grazers to keep the forest underbrush clear of the tinder-like grasses, bushes and small trees that allow flames to jump to the higher forest canopy and get further spread by the wind.
"Goats help prevent forest fires…by eating the dry stuff before the fire season strikes," says Lani Malmberg, owner of Colorado-based Ewe4ic (pronounced "u-for-ik") Ecological Services, which uses goats to gradually and naturally remove weeds and return lands to a healthier more natural state.
Goats have been called in for fire mitigation purposes across parts of California, Arizona and other drought-prone parts of the western U.S. In the Oakland and Berkeley hills regions of California's Bay Area, where the combined effects of drought and a bark beetle infestation have killed thousands of acres of trees, public agencies and residents have enlisted the help of goat herds to suppress weeds and keep down the fire risk in the process for what remains of the area's forest cover.
"The goat clearance scheme is one of the key reasons the Bay Area hasn't had a recurrence of a catastrophic fire in decades," says Tom Klatt, former manager of the Office of Emergency Preparedness at UC Berkeley and the author of UC Berkeley's 2007 Fire Mitigation Program Annual Report.
Other earth-minded land managers are going goat as well. The Nature Conservancy recently hired goats to keep dry grasses and other tinder-like plant matter down at its Hassayampa River Preserve in Arizona, where the constant threat of summer fires haunts nearby homeowners while endangering the integrity of the area's unique and fragile riparian ecosystem.
Using goats to control forest brush may seem like a novel idea, but it's really been around as long as grazing animals have roamed the planet looking for nourishment. But with ever-increasing human development, wild grazers are fewer and farther between. The problem is exacerbated by our building our homes so close to (and sometimes within) forested areas that naturally burn occasionally. Efforts to then suppress all forest fires—even naturally occurring undergrowth burns—to protect these homes have led to "tinderbox" conditions ripe for those large destructive fires that spread for hundreds of miles, blown by the wind from treetop to treetop.
Grazing goats are also used in other endeavors. "Goats can be utilized as an effective bio-control agent to reduce weed populations to economically acceptable levels," says Malmberg, adding that weeding with goats requires no pesticides or herbicides and generates zero greenhouse gas or other harmful emissions.
CONTACTS: Ewe4ic Ecological Services, www.goatseatweeds.com; Office of Emergency Preparedness at UC Berkeley, www.oep.berkeley.edu.
Dear EarthTalk: Is it true that environmental non-profits have been hit hard by the economic downturn, and has this had an impact on their effectiveness?
-- Bridget W., Bainbridge Island, Wash.
Non-profits of every stripe have been suffering from the economic downturn. In a recent survey of 800 U.S.-based non-profits, 75 percent reported feeling the effects of the downturn, with more than half already experiencing significant cuts in funding from both government and private foundation sources.
According to a recently released report from Civic Enterprises and the Democratic Leadership Council entitled "Quiet Crisis: The Impact of the Economic Downturn on the Nonprofit Sector," few of these groups have strong reserves to weather the downturn—more than half have less than three months of operating funds on hand, while three-quarters cannot make it six months on existing cash reserves.
And the outlook is not promising. The Chronicle of Philanthropy, which reports on trends in grantmaking, says that foundation assets have declined by some 28 percent following the economy's nosedive; two-thirds of them expect to have reduced grants significantly by the end of 2009. Many grantmakers have, in fact, suspended grants altogether for the time being.
Despite their funding troubles, many environmental groups continue to provide core services. According to the Environmental Grantmakers Association (EGA), many cash-strapped groups are adapting by using more volunteers to get their work done, and actively seeking partnerships with other groups in order to make the most of limited resources and share overhead costs. And, of course, many green groups have cut costs through hiring freezes, layoffs and forced reductions in pay and hours for existing employees.
To Mark Tercek, president of the non-profit Nature Conservancy, the silver lining in the funding crisis for green groups is that it forces them to operate more efficiently and focus on core priorities: "Non-profits…have to be smart about adjusting to a tougher economic environment, including setting priorities," he says. "If resources are going to be constrained…then organizations have to ask the questions: 'What are we really best at? What are we uniquely positioned to do?'" Tercek adds that the recession also provides an "opportunity to connect the economic stimulus to environmental matters."
And that's just what the Obama administration hopes to do. By encouraging development of green technologies and services, the federal government aims to leverage environmental progress for an overall economic benefit. Most federal funding will go toward incentives for businesses and homeowners to adopt greener ways, but green groups with related expertise are in a good position to benefit as well.
Another boost for green groups could come if Congress passes the Edward M. Kennedy Serve America Act, which aims to flood non-profits with some 250,000 volunteers each year in a program akin to the Peace Corps but on the domestic front. Non-profits are also seeking changes to the federal tax code to further encourage corporate, foundation and individual donations.
CONTACTS: Quiet Crisis Report, www.civicenterprises.net/pdfs/quietcrisis.pdf; EGA, www.ega.org; Serve America Act, www.nationalservice.gov/about/serveamerica.
Dear EarthTalk: I am considering upgrading some older appliances in my home. Where can I find information on which models are the most energy efficient?
-- Jonathan Duda, Olivebridge, N.Y.
There has never been a better time to upgrade some of those older creaky appliances that are gobbling up much more energy (or water) than they need to in your home. Fortunately, most of the sifting-through to find the best values has already been done for you.
The first thing to do when shopping for new equipment is to look for models emblazoned with the blue EnergyStar logo. This helps you zero in on those models that have been determined by the federal government—EnergyStar is a joint program of the U.S. Environmental Protection Agency (EPA) and the Department of Energy—to be at least 10 to 25 percent more energy-efficient (and often much more) than conventional models.
For dishwashers, for example, EnergyStar qualified models use 31 percent less energy and 33 percent less water than conventional machines while performing as well as or better, according to EnergyStar. With clothes washers, EnergyStar models can cut energy use by over a third and water use by half. EnergyStar-rated refrigerators will cut electrical use in half, compared to older machines made before 1993. With air conditioners, the savings is there, too, though at a more modest 10 percent over conventional models.
EnergyStar, which began in 1992 and first evaluated only computers and monitors, is a great jumping off point for evaluating everything from major appliances to home heating and cooling, lighting, home electronics, office equipment and more. The EPA recently extended the label to cover new homes and commercial and industrial buildings.
After first zeroing in on EnergyStar models, be sure to check out the accompanying yellow EnergyGuide sticker, which gets down to the nitty-gritty and estimates how much energy the appliance uses, compares its energy use to similar products and lists approximate annual operating costs. EnergyGuide labels also appear on appliances not EnergyStar compliant. Visit the EnergyStar website (address below) and immerse yourself.
Another way to help sort through the thousands of appliances out there that are EnergyStar-compliant is by checking out the Consumers Union (publisher of Consumer Reports magazine) free Greener Choices website, which compares a wide range of merchandise according to their relative environmental impact.
Greener Choices provides detailed information on dishwashers, washers and dryers, air conditioners, refrigerators and vacuum cleaners. Each appliance is assessed in comparison to other models via the website's Green Buying Guides, which can help consumers decide how green they should go. It also offers up a series of calculators to determine the energy use of your current appliances, new or old. By providing the efficiency and price of various models, the site helps consumers decide how much green "bang" they want for a specific amount of bucks.
CONTACTS: Energy Star, www.energystar.gov; Greener Choices, www.greenerchoices.org.
Dear EarthTalk: I've heard that hybrid engine technology is now being used to power boats. What's happening with that?
-- D. Smith, Portland, Maine
With concerns about climate change and the fate of the world's imperiled oceans and waterways at an all time high, it makes sense that the boating industry would be looking into greener ways to try to do their part and to attract some of those increasing numbers of environmentally conscious customers.
Americans spend 500 million hours zipping around in recreational boats each year. But until recently the engines on these boats were held to much lower efficiency standards than their automotive counterparts. Last year the U.S. Environmental Protection Agency announced new more stringent emissions standards for marine engines—both in-board and outboard—that will go into effect in 2010. In fact, several hybrid boats are already on the market, boasting emission ratings well below the new standards.
The 24-foot Endeavor Green Electric Hybrid can run all day on an electric charge that costs only 11 cents and generates no emissions, kicking into a small diesel generator only if the boat's eight batteries run dry. And when owners can charge the batteries via solar or wind power, the boats have a zero carbon footprint. Florida-based Craig Catamaran Corp. last year launched a hybrid version of its compact catamaran-style speedboat. The sporty little two-seater, which is light enough to be towed by a Mini Cooper or Smart Car, can run for eight hours on less than a gallon of gas, and costs less than $6,000 all in.
For those looking for a larger, more luxurious ride, the 25-foot Frauscher hybrid might be just the ticket. The speedy $155,000 Austrian-built pleasure boat combines an electric engine with a 256 horsepower Steyr diesel motor to allow for emissions-free harbor cruising or high octane speeding across open water.
If you're not quite ready to take the plunge on a hybrid boat yourself, check out one in action on your next visit to San Francisco. The recently retrofitted Hornblower ferry to Alcatraz and Angel islands is powered by several alternative energy sources, including a hybrid diesel-electric system powered by solar cells and wind turbines right on deck. Alcatraz Cruises, the private company that runs the service claims the Hornblower is the first hybrid ferry boat in the country. The 64-foot vessel has an advanced power management system that regulates when and how the different power sources are used so it can make best use of its energy and minimize emissions. Passengers can see many of the technological advancements on the vessel, making for not only a fun and scenic but educational ride.
In another development, the U.S. Navy has reportedly contracted with Solomon Technologies, makers of the famous Zodiac line of rugged inflatable boats, to create a series of hybrid boats where fuel efficiency and stealthy (quiet) passage is of paramount importance. Recreationists, pacifists and Greenpeace anti-whaling activists alike may get the chance to check one out soon, too, as Solomon is already looking into incorporating hybrid technologies into its recreational and commercial product lines as well.
CONTACTS: Endeavour Green, www.endeavourgreen.com; Craig Catamaran, www.craigcat.com; Frauscher Boats, www.frauscherboats.com; Alcatraz Cruises, www.alcatrazcruises.com; Solomon Technologies, www.solomontechnologies.com.
Dear EarthTalk: Hunting seems to be a real controversy among environmental advocates. Can you set the record straight: Is hunting good or bad for the environment?
-- Bill Davis, New York, N.Y.
Like so many hot button issues, the answer to this question depends upon who you ask. On the one hand, some say, nothing could be more natural than hunting, and indeed just about every animal species—including humans—has been either predator or prey at some point in its evolution. And, ironic as it sounds, since humans have wiped out many animal predators, some see hunting as a natural way to cull the herds of prey animals that, as a result, now reproduce beyond the environment's carrying capacity.
On the other hand, many environmental and animal advocates see hunting as barbaric, arguing that it is morally wrong to kill animals, regardless of practical considerations. According to Glenn Kirk of the California-based The Animals Voice, hunting "causes immense suffering to individual wild animals…" and is "gratuitously cruel because unlike natural predation hunters kill for pleasure…" He adds that, despite hunters' claims that hunting keeps wildlife populations in balance, hunters' license fees are used to "manipulate a few game [target] species into overpopulation at the expense of a much larger number of non-game species, resulting in the loss of biological diversity, genetic integrity and ecological balance."
Beyond moral issues, others contend that hunting is not practical. According to the Humane Society of the United States (HSUS), the vast majority of hunted species—such as waterfowl, upland birds, mourning doves, squirrels and raccoons—"provide minimal sustenance and do not require population control."
Author Gary E. Varner suggests in his book, In Nature's Interests, that some types of hunting may be morally justifiable while others may not be. Hunting "designed to secure the aggregate welfare of the target species, the integrity of its ecosystem, or both"—what Varner terms 'therapeutic hunting'—is defensible, while subsistence and sport hunting—both of which only benefit human beings—is not.
Regardless of one's individual stance, fewer Americans hunt today than in recent history. Data gathered by the U.S. Fish & Wildlife Service for its most recent (2006) National Survey of Fishing, Hunting and Wildlife-Associated Recreation, show that only five percent of Americans—some 12.5 million individuals—consider themselves hunters today, down from nine percent in 2001 and 15 percent in 1996.
Public support for hunting, however, is on the rise. A 2007 survey by Responsive Management Inc., a social research firm specializing in natural resource issues, found that 78 percent of Americans support hunting today versus 73 percent in 1995. Eighty percent of respondents agreed that "hunting has a legitimate place in modern society," and the percent of Americans indicating disapproval of hunting declined from 22 percent in 1995 to 16 percent in 2007.
Perhaps matching the trend among the public, green leaders are increasingly advocating for cooperation between hunters and environmental groups: After all, both lament urban sprawl and habitat destruction.
CONTACTS: The Animals Voice, www.animalsvoice.com; HSUS, www.hsus.org; National Survey of Fishing, Hunting and Wildlife-Associated Recreation, www.census.gov/prod/www/abs/fishing.html; Responsive Management Inc., www.responsivemanagement.com
Dear EarthTalk: What's the story with the Florida Panther these days? Is it still teetering on the brink of extinction, or is it on the rebound?
-- Alex T., via email
One of more than 20 subspecies of cougar and native to the southeastern United States, the Florida Panther is most certainly still highly endangered. Biologists estimate that less than 100 of the animals are alive in the wild today, hanging on in the southern tip of Florida below the Caloosahatchee River. Their current range represents less than five percent of where they originally roamed across Florida, Louisiana, Arkansas, Mississippi, Alabama, Georgia and parts of Tennessee and South Carolina.
Perceived as a threat to humans, livestock and game animals, the Florida Panther was persecuted and hunted to near extinction by the mid-1950s. Today, primary threats are habitat loss and fragmentation as a result of human development. According to Defenders of Wildlife, the main culprits in the decline of the animals' numbers are: urban sprawl; the conversion of once diversified agricultural lands into intensified industrial farming uses; and the loss of farmland to commercial development. Other factors include collisions with automobiles, territorial disputes with other panthers as habitat shrinks, and inbreeding resulting from their isolated population. Additional threats include mercury poisoning from the fallout of coal-fired power plants, parasites, and diseases such as feline leukemia and feline distemper.
Efforts to help the Florida Panther recover have had limited success. Many public agencies and nonprofit groups have worked together to try to bring back the panther—Florida's state animal—since it was first listed as endangered by the federal government back in 1967. According to the U.S. Fish and Wildlife Service (USFWS), panthers require large areas of contiguous habitat: Each breeding unit of one male and two to five females requires some 200 square miles of territory to thrive. Biologists report that a population of 240 panthers requires between 8,000 and 12,000 square miles of habitat and sufficient genetic diversity in order to avoid inbreeding as a result of small population size. The introduction of eight female cougars from a closely related Texas population in 1995 helped mitigate inbreeding problems, but most analysts fear that the effort was too little, too late for the threatened cats.
Since the animals were first listed as endangered, the human population of Florida has more than tripled, meaning that rescue efforts are swimming against the tide. Defenders of Wildlife reports that, since 2004, human-panther encounters have been on the rise, as have documented instances of panthers preying on livestock and pets. In response, the USFWS, the National Park Service and the Florida Fish and Wildlife Conservation Commission have drafted a landmark Florida Panther Response Plan, which guides game managers and law enforcement officials in handling such interactions in ways that ensure public safety while recognizing the need to preserve dwindling Florida Panther populations.
Readers can help by getting educated about the plight of the big cats and pressuring their elected officials to take action. Another way to help is by supporting wildlife groups working on the issue. Defenders of Wildlife's "Adopt a Panther" program, for one, puts donations into public education, preserving habitat and promoting sound transportation planning to prevent panther deaths on Florida's roads and highways.
CONTACTS: Defenders of Wildlife, www.defenders.org; USFWS, www.fws.gov; Florida Fish and Wildlife Conservation Commission, www.myfwc.com.
Dear EarthTalk: I'd like to know the relative electricity cost of utility scale solar and wind plants versus rooftop residential solar. In other words, how can I know whether to subsidize my utility's alternative energy plant or renovate my own home?
-- Randy Wilson, Flagstaff, Ariz.
Making such a determination is complex, but you could start with "In My Backyard," a new online tool by the National Renewable Energy Laboratory (NREL). You first need to know your electricity usage and what size solar photovoltaic (PV) system or wind turbine you could install. Then, using Google Earth maps and data on the amounts of sunshine and wind at your location, the tool will estimate the electricity you could get from a certain size wind turbine or PV array installed on your property.
The costs to install renewable energy systems vary greatly by location, warn researchers at the Lawrence Berkeley National Laboratory, which is supported by the Department of Energy (DOE). And kilowatt hour (kWh) costs vary by utility, as do state and local financial incentives. One piece of good news: The federal Investment Tax Credit was expanded and extended this year. It allows for 30 percent of the cost of your system to be deducted from your federal tax bill, and is good through 2016.
Comparing the cost of going it alone to that of simply buying green power through your utility is not a simple equation, either. You can support your utility's renewable power infrastructure by paying a premium on your electric bill, or you can buy renewable energy certificates—also known as green tags—even if your utility does not offer green power (green tags inject renewable energies into the grid even if they don't come back to you via your own utility). To decide which equation is better for you, compare the costs of those programs over the same time period with the cost of building and maintaining your own system (minus any installation credits and/or revenues from selling your excess electricity back to the utility). That would give you the relative costs and return-on-investment.
But that's still not the whole picture: Another question is whether your home system can continue to produce energy more cost-effectively than your utility, as it brings more and more green energy sources into its mix. Lawrence Berkeley says no, essentially. A February 2009 report summarizing the costs of PV from 1998 to 2007 concluded that larger systems averaged a 25 percent lower cost than the smallest ones.
The same is true for wind power, says the American Wind Energy Association. The group's February 2005 report calculates that a large wind farm can deliver electricity at a nearly 40 percent lower cost than a small one. It also can take advantage of economies of scale in lower operational and maintenance costs.
The bottom line is this: Decades ago, when widespread use of alternative energy was still only a dream, building one's own private source of home power was the only way to get off the carbon-intense grid and ensure that your own energy needs left little footprint. But today, with considerably more renewable energy sources coming online or about to do so in quantum leap measures—and at much greater efficiencies than can be achieved privately—the best bet may well be to forego the go-it alone path and support your utility's efforts to generate green power not just for your own household but for everyone.
CONTACTS: NREL's "In My Backyard" Tool, www.nrel.gov/eis/imby; DOE Green Power Network, http://apps3.eere.energy.gov/greenpower.
Dear EarthTalk: I've heard that cars can be modified to run on water. How is this possible?
-- Diane McMorris, Rockport, Maine
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, Neb.
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.
Dear EarthTalk: If train travel is so much less polluting than driving or flying, why are passenger rail options in the U.S. so limited compared to Europe? And is anything being done to shift more travelers over to American rail lines from cars and planes?
-- Jeffrey Orenstein, Bradenton, Fla.
It's true that train travel is one of the lowest impact ways to get from point to point short of walking, jogging or bicycling. In the early part of the 20th century, with car and air travel both in their infancies, taking the train was really the only practical way for Americans to get from city to city. And take the train they did: By 1929 the U.S. boasted one of the largest and most used rail networks in the world, with some 65,000 railroad passenger cars in operation across some 265,000 miles of track.
But a concerted campaign by U.S. carmakers to acquire rail lines and close them, along with a major push in Congress to build the world's most extensive interstate highway system, combined to shift Americans' tastes away from rail travel and toward cars. As a result, while Europe focused on building its own rail networks, the U.S. became the ultimate auto nation, with more cars per capita than anywhere else in the world. By 1965 only 10,000 rail passenger cars were in operation across just 75,000 miles of track.
In response to the declining use of America's rail network, the U.S. government created Amtrak in 1971 to provide intercity passenger train service across the country, running mostly on pre-existing track already in use for freight transport. Today Amtrak runs some 1,500 rail passenger cars on 21,000 miles of track connecting 500 destinations in 46 states. In 2008, upwards of 28 million passengers rode Amtrak trains, representing the sixth straight year of record ridership for the publicly-owned rail line. Despite this growth, the U.S. still has one of the lowest inter-city rail usage rates in the developed world.
But that may all change soon. In the spring of 2009, President Obama allocated $8 billion of his stimulus package toward development of more high-speed rail lines across the country, citing the need to reduce both greenhouse gas emissions and reliance on foreign oil. Currently only one high-speed rail line exists in the U.S., Amtrak's Acela Express, which can reach speeds of 150 mile per hour on its Washington, D.C. to Boston route. The success of high-speed, high-efficiency "bullet" trains in Asia and Europe—where train rides can be as fast as flying but without the long waits and security hassles—has helped convince American transportation analysts that the U.S. should also take the high speed rail plunge.
The first round of federal funding will go toward upgrading and increasing speeds on existing lines, but the majority of it will be used to jump-start construction of new high speed lines in 10 corridors across the country, including in northern New England, across New York State, across Pennsylvania, in and around Chicago, throughout the Southeast, and up and down the length of the west coast.
A 2006 study by the Center for Clean Air Policy and the Center for Neighborhood Technology concluded that building a high speed rail system across the U.S. (similar in scope to that proposed by Obama) would likely result in 29 million fewer car trips and 500,000 fewer plane flights each year, saving six billion pounds of carbon dioxide emissions—the equivalent of removing a million cars from the road annually.
CONTACTS: Amtrak, www.amtrak.com; Center for Clean Air Policy, www.ccap.org; Center for Neighborhood Technology, www.cnt.org.
Dear EarthTalk: To what extent does human population growth impact global warming, and what can be done about it?
-- Larry LeDoux, Honolulu, Hawaii
No doubt human population growth is a major contributor to global warming, given that humans use fossil fuels to power their increasingly mechanized lifestyles. More people means more demand for oil, gas, coal and other fuels mined or drilled from below the Earth's surface that, when burned, spew enough carbon dioxide (CO2) into the atmosphere to trap warm air inside like a greenhouse.
According to the United Nations Population Fund, human population grew from 1.6 billion to 6.1 billion people during the course of the 20th century. (Think about it: It took all of time for population to reach 1.6 billion; then it shot to 6.1 billion over just 100 years.) During that time emissions of CO2, the leading greenhouse gas, grew 12-fold. And with worldwide population expected to surpass nine billion over the next 50 years, environmentalists and others are worried about the ability of the planet to withstand the added load of greenhouse gases entering the atmosphere and wreaking havoc on ecosystems down below.
Developed countries consume the lion's share of fossil fuels. The United States, for example, contains just five percent of world population, yet contributes a quarter of total CO2 output. But while population growth is stagnant or dropping in most developed countries (except for the U.S., due to immigration), it is rising rapidly in quickly industrializing developing nations. According to the United Nations Population Fund, fast-growing developing countries (like China and India) will contribute more than half of global CO2 emissions by 2050, leading some to wonder if all of the efforts being made to curb U.S. emissions will be erased by other countries' adoption of our long held over-consumptive ways.
"Population, global warming and consumption patterns are inextricably linked in their collective global environmental impact," reports the Global Population and Environment Program at the non-profit Sierra Club. "As developing countries' contribution to global emissions grows, population size and growth rates will become significant factors in magnifying the impacts of global warming."
According to the Worldwatch Institute, a nonprofit environmental think tank, the overriding challenges facing our global civilization are to curtail climate change and slow population growth. "Success on these two fronts would make other challenges, such as reversing the deforestation of Earth, stabilizing water tables, and protecting plant and animal diversity, much more manageable," reports the group. "If we cannot stabilize climate and we cannot stabilize population, there is not an ecosystem on Earth that we can save."
Many population experts believe the answer lies in improving the health of women and children in developing nations. By reducing poverty and infant mortality, increasing women's and girls' access to basic human rights (health care, education, economic opportunity), educating women about birth control options and ensuring access to voluntary family planning services, women will choose to limit family size.
CONTACTS: United Nations Population Fund, www.unfpa.org; Sierra Club's Global Population and Environment Program, www.sierraclub.org/population; Worldwatch Institute, www.worldwatch.org.
Dear EarthTalk: Do insulating paints actually insulate and save energy? If they do, are they environmentally friendly to use?
-- Bob Dibrindisi, Easthampton, Mass.
Paint additives that claim insulating qualities have been marketed since the late 1990s, but energy research organizations have not confirmed their insulating value. For its part, the U.S. Environmental Protection Agency (EPA) does not recommend using paints or coatings in place of traditional bulk insulation. "We haven't seen any independent studies that can verify their insulating qualities," the agency reports. The federal government does rate roofing paint for its energy efficiency, but such findings only take into account a substance's ability to reflect heat off the roof—not its insulating properties per se—to keep the building cooler.
According to the Department of Energy's Oak Ridge National Laboratory, the use of so-called insulated paints is in most cases "difficult to justify on the basis of savings in energy costs alone." Meanwhile, the non-profit EnergyIdeas Clearinghouse, a partnership between Washington State University and the nonprofit Northwest Energy Efficiency Alliance, found that under ideal circumstances insulating paints can achieve a "reduction in heat gain" of around 20 percent on freshly-painted sun-exposed walls, but notes that such walls will only face direct sunlight for a limited part of even the clearest summer day. Also, the clearinghouse reports that "heat gain reductions…are significant only for sun-bathed surfaces" and that the "reflectivity of the painted surface generally declines considerably with time."
Alex Wilson of the website BuildingGreen.com is not a fan of insulating paints: "To say that there is a lot of hype about insulating paints … is an understatement," he tells the website Treehugger.com. "The Internet is rife with claims of paints that dramatically reduce heat transfer—usually based on some technological magic spun off from NASA. While these products may have some relevance in the extreme conditions of outer space, manufacturers of paints containing [insulating additives] are making claims that defy the laws of physics…when they claim they can save significant energy in buildings."
Nevertheless, for certain applications, especially in concert with traditional forms of insulation underneath, insulating paint can help reduce energy expenditures and air conditioning bills accordingly. For those who want to forge ahead with insulating paint despite the limited benefits, some of the leading brands to look for include Insuladd, Hy-Tech, Therma-Guard and Eagle Coatings' SuperTherm.
Adding insulating paint should merely be the icing on the cake of an otherwise well-conceived plan to cut heating and cooling costs. Installing a traditional form of insulation would be the first defense. A reflective, radiant barrier on the roof structure in the attic also could offer significant help, according to the Florida Solar Energy Center. Thermal-pane windows and energy-conscious practices will contribute to the effort. Finally, consider trees and other landscape shading, which the U.S. Department of Energy recommends as an effective way of passively cooling your home. For more ideas, visit the "do-it-yourself energy audit tool" on the Lawrence Berkeley National Laboratory's Home Energy Saver website.
CONTACTS: U.S. EPA, www.epa.gov; EnergyIdeas Clearinghouse, www.energyideas.org; Insuladd, www.insuladd.com, Hy-Tech, www.hytechsales.com; Eagle Coatings, www.eaglecoatings.net; Therma-Guard, www.befreetech.com/thermaguard.htm; Home Energy Saver, www.hes.lbl.gov.
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