Dear EarthTalk: I've noticed that wildflower blooms in the mountains have been coming earlier and earlier in recent years. Is this a sign of global warming? And what does this mean for the long term survival of these hardy yet rare plants?
– Ashley J., via e-mail

As always, it’s hard to pin specific year-to-year weather-variations and related phenomena—including altered blooming schedules for wildflowers—on global warming. But longer term analysis of seasonal flowering patterns and other natural events do indicate that global warming may be playing a role in how early wildflowers begin popping up in the high country.

Aspen sunflowers, like the one's pictured here, used
to first bloom in mid-May, but are now are doing so in
mid-April, a full month earlier. University of Maryland
ecologist David Inouye thinks that smaller snow packs
in the mountains are melting earlier due to global
warming, in turn triggering early blooms.
beautifulcataya, courtesy Flickr

University of Maryland ecologist David Inouye has been studying wildflowers in the Rocky Mountains near Crested Butte, Colorado for four decades, and has noticed that blooms have indeed begun earlier over the last decade. Aspen sunflowers, among other charismatic high country wildflowers, used to first bloom in mid-May, but are now are doing so in mid-April, a full month earlier. Inouye thinks that smaller snow packs in the mountains are melting earlier due to global warming, in turn triggering early blooms.

Smaller snow packs not only mean fewer flowers (since they have less water to use in photosynthesis); they can also stress wildflower populations not accustomed to exposure to late-spring frost. According to Inouye’s research, between 1992 and 1998 such frosts killed about a third of the Aspen sunflower buds in some 30 different study plots; but more recently, from 1999 through 2006, the typical mortality rate doubled, with three-quarters of all buds killed by frost in an average year thanks to earlier blooming. Read the rest of this entry »

Dear EarthTalk: I heard that some wind farms use fossil fuels to power their generators when the wind won’t. Doesn’t that defeat their whole renewable energy purpose? Why not let the wind power it or not? Also, I've heard that the low-frequency sounds generated by these turbines can harm people and animals. Is this true?
– Ryan Lewis, Plainwell, MI

Indeed, one of the major drawbacks to wind power is the fact that, even in windy locations, the wind doesn’t always blow. So the ability of turbines to generate power is intermittent at best. Many turbines can generate power only about 30 percent of the time, thanks to the inconsistency of their feedstock.

Some wind energy companies have developed back-
up systems that can spin turbines even when the
wind isn't blowing, thus optimizing and keeping
consistent the power output. Colorado-based Hybrid
Turbines Inc., for example, makes systems that marry
a natural gas-based generator to a wind turbine. Even
with that fossil fuel usage, the electricity produced
is much cleaner than burning coal.
Jorge Lascar, courtesy Flickr

In order to overcome this Achilles’ heel of intermittent production, some wind companies have developed back-up systems that can spin turbines even when the wind isn’t blowing, thus optimizing and keeping consistent the power output. For example, Colorado-based Hybrid Turbines Inc. is selling wind farms systems that marry a natural gas-based generator to a wind turbine. “Even if natural gas is used, the electricity produced…is twice as environmentally clean as burning coal,” reports the company. Better yet, if a user can power them with plant-derived biofuels, they can remain 100 percent renewable energy-based.

While some wind energy companies may want to invest in such technologies to wring the most production out of their big investments, utilities aren’t likely to suffer much from the intermittent output if they don’t. Even the utilities that are most bullish on wind power still generate most of their electricity from other more traditional sources at the present time. So, when wind energy output decreases, utilities simply draw more power from other sources—such as solar arrays, hydroelectric dams, nuclear reactors and coal-fired power plants—to maintain consistent electrical service. As such, reports the American Wind Energy Association, utilities act as “system operators” drawing power from where it’s available and dispatching it to where it is needed in tune with rising and falling power needs. Read the rest of this entry »

Dear EarthTalk: Within my lawn I have over 100 citrus, mango and avocado trees. When I use Scott’s Bonus S Weed and Feed, am I feeding my new fruit any poison? Will the weed killer be taken up by the fruit?
– Brit Brundage, Fairfield, CT

In short, yes and yes: You will jeopardize the health of your fruit trees and your yard in general if you use such products. Scott’s Bonus S Weed and Feed, as well as many other “weed-and-feed” fertilizers (Vigero, Sam’s, etc.), contain the harsh chemical herbicide atrazine, which excels at terminating fast-growing weeds like dandelions and crabgrass but can also kill other desirable plants and trees and damage your entire yard as toxin-carrying root systems stretch underground in every corner and beyond.

Howard Garrett, founder of the Dirt Doctor website,
recommends sticking to organic fertilizers — which
contain naturally buffered blends of major nutrients,
trace minerals, organic matter and carbon — for the
well being of plants, humans and animals alike.
The Dirt Doctor

Howard Garrett, a landscape architect who founded the DirtDoctor.com website and is an evangelist for natural organic gardening and landscaping, points out that anyone who reads the label on such products will learn that even manufacturers don’t take their health and environmental effects lightly. Some of the warnings right there in black and white on the Scott’s Bonus S Weed and Feed packaging include precautions against using it “under trees, shrubs, bedding plants or garden plants” or in the general vicinity of any such plants’ branch spreads or root zones. Read the rest of this entry »

Dear EarthTalk: I always thought eating fish was healthy, but now I’m concerned about mercury in tuna and other fish. Are there any fish that are still safe to eat?
– Brit Brundage, Fairfield, CT

You should be concerned about contaminants in certain fish, including some kinds of tuna. The non-profit Environmental Defense Fund (EDF) recommends minimizing consumption of albacore (white) tuna, a large fish that accumulates moderate amounts of mercury in its fatty tissue. But other kinds of (smaller) tuna, such as skipjack (usually canned as “light”), which accumulates a third the amount of mercury as albacore, are OK to eat in moderation, though consumption by those under age seven should be limited.

The Environmental Defense Fund recommends
minimizing consumption of albacore (white) tuna, a
large fish that accumulates moderate amounts of
mercury in its fatty tissue. But other kinds of
(smaller) tuna, such as skipjack (usually canned as
“light”), which accumulates a third the amount of
mercury as albacore, are OK to eat in moderation,
though consumption by those under age seven
should be limited.
Mark H. Anbinder, courtesy Flickr

To further complicate the issue, some canned light tuna may contain yellowfin tuna, which has mercury levels similar to those of albacore; these products are sometimes but not always labeled as “gourmet” or “tonno”—and their consumption should be limited, even by adults.

Mercury, a known “neurotoxin” (a poison that affects the nervous system), is particularly insidious because it is widespread in our oceans, primarily due to emissions from coal-burning power plants. These smokestacks deposit mercury into waterways, which carry it to the ocean where bacteria convert it into methylmercury. Fish then ingest it with their food and from water passing over their gills. Read the rest of this entry »

Dear EarthTalk: I heard about a supposed dangerous chemical called “triclosan” that is in many personal care and other consumer products. Can you enlighten?
– Carl Stoneman, Richland, WA

Triclosan is a synthetic chemical compound added to many personal and household care products to inhibit illness by preventing bacterial infection. It works by breaking down the biochemical pathways that bacteria use to keep their cell walls intact, and as such kills potentially harmful germs if used in strong enough formulations. First developed as a surgical scrub back in 1972, triclosan is now used in upwards of 700 different consumer-oriented products, many of which people use more than once a day. They include hand soaps, deodorants, toothpastes, kids’ toys, yoga mats and, of course, hand sanitizers.

Manufacturers that use triclosan in their products
insist that the synthetic chemical helps reduce
infections. But numerous studies have shown that
washing hands with products containing triclosan was
no more effective in preventing infectious illness than
plain soaps. Other research even links triclosan to
various human health and environmental problems.
Jack Black's Stunt Double, courtesy Flickr

Whether triclosan is actually as effective as advertised, especially in the small doses found in consumer products, is a topic of much debate. Manufacturers insist that the product helps reduce infections. But researchers from the University of Michigan’s School of Public Health found, after surveying 27 different studies conducted between 1980 and 2006 on the effectiveness of antibacterial soaps, that washing hands with products containing triclosan was no more effective in preventing infectious illness—and did not remove any more bacteria—than plain soaps. The analysis, “Consumer Antibacterial Soaps: Effective or Just Risky?” was published in 2007 in the peer-reviewed journal, Clinical Infectious Diseases. According to lead researcher Allison Aiello, triclosan—because of the way it reacts in living cells—may cause some bacteria exposed to it to become resistant to amoxicillin and other commonly used antibacterial drugs, but she adds that more research is needed to bear out this hypothesis. Read the rest of this entry »

Dear EarthTalk: Is it true that bananas are taboo for anyone who is concerned about rainforest destruction? Even if I seek out “fair trade” or organic bananas, am I feeding the demand which is causing rainforest to be cleared?
– Laura Barnard, Hillsboro, OH

Sadly, the short answers to these questions may be yes and yes for now, but that may change as the $5 billion banana industry slowly comes to terms with greener forms of production. Historically, growing the world’s most popular fruit has caused massive degradation of rainforest land across the tropics, spread noxious chemicals throughout formerly pristine watersheds, and poisoned and exploited farm workers.

Banana production has long been known for its
environmental and human rights abuses, which have
included the use of dangerous pesticides, water
pollution, deforestation and poor working conditions.
But that is slowly changing thanks to the work of The
Rainforest Alliance, the Sustainable Agriculture
Network and other nonprofit groups.
Ian Ransley Design, courtesy Flickr

“Banana plantations were infamous for their environmental and social abuses, which included the use of dangerous pesticides, poor working conditions, water pollution and deforestation,” reports the Rainforest Alliance, a New York-based non-profit that has been working to improve worker and environmental conditions in the industry since 1990. “Pesticide-impregnated plastic bags, which protect bananas as they grow, often littered riverbanks and beaches near banana farms, while agrochemical runoff and erosion killed fish, clogged rivers and choked coral reefs.” Also, the proximity of housing to banana fields, coupled with lax regulations for pesticide handling, led to frequent illness among workers and people living near the plantations. Read the rest of this entry »

Dear EarthTalk: What is “kenaf” paper? From what I've heard, it’s good for the environment. But what exactly are its benefits and where can I obtain some?
– Tiffany Mikamo, via e-mail

Kenaf, a fast-growing, non-invasive annual hibiscus plant related to cotton, okra and hemp, makes ideal paper fiber as well as great source material for burlap, clothing, canvas, particleboard and rope. Its primary use around the world today is for animal forage, but humans enjoy its high-protein seed oil to add a nutritious and flavorful kick to a wide range of foods. In fact, kenaf has been grown for centuries in Africa, China and elsewhere for these and other purposes, but environmentalists see its future in replacing slower-growing trees as our primary source for paper.

U.S. Department of Agriculture research shows that
kenaf yields some six to 10 tons of dry fiber per acre
per year, which is three to five times more than the
yield of Southern Pine trees, now the dominant paper
pulp source in the U.S. Kenaf also absorbs more
carbon dioxide than any other plant or tree.
Pictured: Bill Loftus tends kenaf plants at the
Kenaf Research Farm.
Credit: Kenaf Research Farm

U.S. Department of Agriculture (USDA) research shows that kenaf yields some six to 10 tons of dry fiber per acre per year, which is three to five times more than the yield of Southern Pine trees—now the dominant paper pulp source in the U.S. And to top it off, researchers believe kenaf absorbs more carbon dioxide—the chief “greenhouse gas” behind global warming—than any other plant or tree growing. Some 45 percent of dry kenaf is carbon pulled down from the atmosphere via photosynthesis.

No wonder environmentalists are so bullish on kenaf for our common future. “The more kenaf we grow, we can not only absorb significant amounts of the carbon dioxide that is responsible for global warming,” says Bill Loftus of the non-profit Kenaf Research Farm, “but also educate the world on how to be self-sustainable through kenaf’s many properties of providing food, shelter and economic opportunities.” Read the rest of this entry »

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.

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."
Lorna Baldwin, PBS NewsHour, Courtesy Flickr

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. Read the rest of this entry »

Dear EarthTalk: The U.S. got socked with several major storms this past winter. Local weather reports never mentioned this as odd. But is it a sign of global warming?
– R.A. Forbes, via e-mail

Weather patterns and trends are notoriously unpredictable, varying due to a great many different inputs. While it's true that snowier, stormier winters could be the result of global warming, many meteorologists believe that El Nino — a climate pattern involving warmer-than-usual sea temperatures across the tropical Pacific that affects weather all over the globe — is mainly to blame for this past winter's ongoing white misery.

We must keep in mind the difference between climate
and weather. Climate is the average of weather over at
least three decades, which means that specific
storms or even individual snowy winters, let alone
other types of extreme weather, cannot be considered
evidence of either the existence or nonexistence of
global warming.
Tanya Liu, courtesy Flickr

According to Joe Bastardi, a meteorologist with the Pennsylvania-based AccuWeather forecasting service, the current El Nino — they occur once every three to seven years — has been "very strong, prompting many major blizzards for the mid-Atlantic region." By altering the intensity of the atmospheric jet stream, El Nino can force cold air from Northern Canada to push down into the United States, converting the moisture in clouds into falling snow as temperatures drop.

Bastardi believes that El Nino is exacerbating an already ongoing trend of cooling in the Pacific that is part of natural cyclical patterns of heating and cooling unrelated to global warming. "When you get an El Niño with a cold Pacific, you get crazy winters in the East," he told National Geographic News. Read the rest of this entry »

Dear EarthTalk: What's being done to clean up hog farming operations in places like Iowa and North Carolina and others where the industry is quite large? I've heard horrific stories about man-made "lagoons" of animal waste spilling into and fouling rivers and groundwater and the like.
– John Schmid, Fremont, California

Hog farming has always been a messy business, but surging demand for pork in recent years has exacerbated an already foul problem: dealing with the continual production of the bodily waste of thousands of animals. Pigs are kept in tight quarters and their waste is channeled into huge open-air lagoon pits and sprayfields. The lagoons can rupture during heavy rains, unleashing a torrent of bacteria- and virus-laden feces and urine into nearby groundwater, lakes and streams. Likewise, sprayfields, where some farmers discard animal waste by spraying it over otherwise unused land, can pollute surrounding waterways and contaminate drinking water. Another side effect is air pollution: The lagoons and sprayfields emit methane (a leading greenhouse gas) and ammonia (a respiratory irritant) into the atmosphere, the foul odors sullying the air quality — and neighbors' quality of life — for miles around.

On hog farms, pigs are kept in tight quarters and their
waste is channeled into huge open-air lagoon pits like
the one shown here at a Smithfield Foods operation in
Jones County North Carolina on the Trent River. These
lagoons can rupture during heavy rains, unleashing a
torrent of bacteria- and virus-laden feces and urine
into nearby groundwater, lakes and streams.
Rick Dove (www.doveimaging.com)

The problem has been especially bad in North Carolina, where the number of hogs raised has gone up fourfold in the last two decades — hog farmers there now raise and slaughter some 10 million hogs a year. In 1995, a hog waste lagoon overflow at Ocean View Farms in North Carolina sent 20 million gallons of hog waste into the New River, causing massive fish kills and contaminating drinking water in several neighboring communities. And the torrential rains and flooding that accompanied 1999's Hurricane Floyd wreaked havoc on hog farm waste lagoons and surrounding ecosystems across North Carolina. Read the rest of this entry »