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.
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, AZ
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.
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