According to authors Brett A. Melbourne and Alan Hastings, current mathematical models to predict extinction rates focus too much on events that happen to individuals, such as an ape falling out of a tree and dying, or environmental factors, such as rainfall fluctuations.

But Melbourne and Hastings have come up with several additional factors, including critical information such as gender ratios, size variations within a species, behavioral differences, randomness in births and deaths, and reproductive success. Factoring these variables into their calculations shows a much grimmer picture of species' fate, and suggests that many species could go extinct in "months" rather than the years originally predicted.

The scientists say their model could be used to re-classify numerous species which have previously been considered "threatened" as officially "endangered."

Their research conclusions come from studying beetles in a controlled experiment, but the authors say "the effect we have uncovered here will be larger in natural populations."

Even the IUCN, which publishes the annual Red List of Threatened Species, acknowledges that current extinction models don't show the whole picture. "We are certainly underestimating the number of species that are in danger of becoming extinct," Craig Hilton-Taylor, manager of the IUCN red list unit, told The Guardian,  "because there are around 1.8m described species and we've only been able to assess 41,000 of those."

Why do I get the feeling my job just became much harder?

Choose cutlets from a fowl who's led a natural, unconfined, beaks-on life, and meat from cattle who not only knew what grass is, but spent most of their lives on pasture. We don't want any products from animals who've been dosed with antibiotics, overuse of which is leading to the rise of antibiotic-resistant bacteria. And we do want the freshest in-season vegetables, free of pesticide residues, grown by local or regional farmers. Here's how to find 'em:

* Type in your zip code to find local, sustainable, organic meat, dairy and produce from nearby farmers' markets, butchers, farmers, stores, and restaurants, at the wonderful Eat Well Guide site of Sustainable Table, which also produces the award-wining Meatrix film series. 

* Look for the following labels on poultry and meat. None permit antibiotics or growth hormones, or feeding of animal parts to animals.

*American Grassfed Association:  Cows, sheep, goats eat grass, period, and standards require they spend most of their lives outside in the pasture. Will soon be third-party-certified by the Food Alliance (see below).

*Animal Welfare Approved: This label, which is exclusive to family farms, guarantess outdoor living to cows and chickens alike and recently received top ratings from the World Society for Protection of Animals.

Certified Humane: Oddly for a humane label, pasture time is not specified, although comfortable shelter and gentler handling are.

* Food Alliance Certified: Sets clear ecologically responsible standards for vegetables, fruits and animal raising. Pasturage and humane slaughtering are required .

*USDA Organic:  Better for you, but not necessarily for the animals. They eat only 100% certified organic grass, corn or grain, but, while they're required to have "access" to pasture, this is not clearly defined the way it is with the labels above.

Now for that other food issue!  In the annals of barbecue, "carbon" could mean either torched meat or charcoal (charbons de bois, per the French, who will be grilling like mad, too, on July 14th, their own Independence Day). Nowadays,  it also signifies the carbon footprint of our barbecue fuel and food. According to Bon Appetit Management's cool food calculator, which assigns points to the Greenhouse Gas (GHG) emissions caused by foods, 4,500 points a day is a "high carbon" diet. BAM suggests we try for more like 2500 a day, or at least reduce our current tally by 25%. Now to the 'cue.

Choose a 4 oz. grilled beef tenderloin and you blow out the top of the BAM thermometer at 7,500  points. Top round, on the other hand, is 4,000 points. But grilled chicken only runs you 579 points and grilled seasonal vegetables, only 95 points.  Try it yourself by clicking here.

For a quick foodie read, seeTracey Ryder's "A Free-Range, Local Chicken in Every Pot," in the summer issue of Cliff Feigenbaum's Green Money Journal. She's the publisher of Edible Communities, a series of 50 regional eating guides with recipes based on local foods.

And Happy 4th of July weekend. Cluck-cluck!

While the Kyoto Protocol does not regulate the gas, given its widespread use in manufacturing, perhaps it should, which would force companies to track and report their emissions. So suggest Michael Prather and Juno Hsu, of the University of California, Irvine in a newly published paper in the journal Geophysical Research Letters. They report that this year’s production of nitrogen trifluoride, in terms of its global warming potential, is equivalent to 67 million metric tons of carbon dioxide—which, if it ends up in the atmosphere, would make it worse than the world’s largest coal-fired power plants.

The three major gases used in manufacturing semiconductors, LCDs, and photovoltaics are nitrogen trifluoride, silane, and ammonia, according to this article. NF3 can help clean up the reactors used in chemical vapor deposition, in which very thin layers of substances—silicon, carbon fiber, or really anything—are deposited on wafers. So as the market for thin-film solar technologies matures, expect an increase in the prevalence of these gases.

But the use of nitrogen trifluoride is definitely not all bad. This boutique gas was initially investigated as a promising replacement in semiconductor manufacturing for perfluorocarbons, which have a significantly worse global warming potential than nitrogen trifluoride, leading to not only an environmental upgrade but also an economic one, in the form of a 30% improvement in the etching process of microelectronics.

The very features that make this gas good for etching silicon and cleaning away unwanted deposits, however, make it rather unfriendly to human life—which is why chemistry labs have fume hoods and other apparatuses for protecting workers from exposure. So it’s quite unlikely that enormous quantities of it are escaping into the great beyond. (For more on what to do if you come face to face with this moldy-smelling, kidney-eating gas, here’s a data sheet.)

The takeaway message: perhaps nitrogen trifluoride should be monitored more carefully, with international regulations to back it up. But panic need not ensue. For more reasons not to panic, check out this sober assessment.

A. You could indeed forgo the commercial compost bin, no problemo. Much of what you read about composting almost makes it sound like you need a degree in chemistry to do it properly, but the truth is, organic matter decomposes with or without our coaxing. Simply making a little heap of leaves and grass in a corner of your yard is actually a perfectly reasonable way to compost, explains Carey Pulverman, a veteran composting instructor at Lower East Side Ecology Center in New York City. It’s definitely better than sending your yard waste to a landfill, and you’ll eventually be rewarded with some fluffy, fertile, organic matter that you can incorporate back into your garden. You can also just use your leaves and clippings for mulch by piling them around shrubs and plants to help keep the soil moist and choke out weeds That said, a simple bin would help keep your compost neat, ward off pests, and accelerate decomposition—all of which are especially important if you also want to compost food scraps, too. You still don’t have to buy a pricey, high-tech bin, though. New York City, like many other cities, offers subsidized bins to all residents for only $20. Another cheap, compact option: drill some ventilation holes in a plastic or metal garbage can (decomposition does require air). Happy decomposition.

-         Sarah Schmidt

Eco-inquiries, conundrums, snafus? Write to askplenty@plentymag.com.

So whether you’ll be watching the Macy’s fireworks, listening to the Boston Pops, or just shooting the breeze in the backyard, spend a few minutes considering these easy steps you might take to green your stars and stripes this year. Then slip into your organic, non-toxic blue jeans, strap on your fair trade sandals, and enjoy the festivities in good conscience.

If you haven’t got a push mower, borrow one from a neighbor, or invest in one of your own. With gas prices skyrocketing the way they are, it’ll pay for itself in no time. You might even finally build up some biceps.

Next, be sure to disinvite the mosquitoes and no-see-ums to your party: citronella is the miracle bug-repellent scent when it comes to outdoor gatherings. People love it. Mosquitoes can’t stand it. Set some citronella candles out on your porch or lawn, and keep some natural, DEET-free bug spray (available at most natural food stores) on hand for guests. Some other delicious scents that bugs will go out of their way to avoid include: cedar, verbena, geranium, lavender, pine, cinnamon, rosemary, and peppermint.

Eat, drink…
We’ve said it before, and we’ll say it again: Corn-fed cows are on drugs. If beef is going to feature in your 4th of July feast, grass-fed is undoubtedly the way to go. The corn-based feed most cattle are given (meant to fatten them up more quickly) is so difficult for them to digest that if their owners didn’t keep them hopped up on daily doses of antibiotics, they’d fall sick with terrible stomach conditions like acidosis.

Overuse of antibiotics is bad news for soil and water health, and also for humans. You’ve read the news lately about bacterial strains that are antibiotic resistant? That’s thanks, in part, to all the antibiotics we’re consuming through corn-fed beef. Genuine grass-fed beef, though, comes from healthier, happier, leaner, and more humanely treated animals. It’s also higher in beta carotene (Vitamin A), conjugated linoleic acid (CLA), and Omega-3 fatty acids, but lower in fat and cholesterol.

As for the rest of your meal, go for organic and locally grown produce whenever possible. Visit your farmers’ market for some sweet corn on the cob, loose leaf spinach, carrots, and fresh local blueberries. Pick up some beets and whip them up in a tangy (and appropriately colored) beet salad. Many farmers’ markets even offer free-range, antibiotic-free chicken. For dessert, throw some organic and fair trade chocolate chips in those brownies. Go crazy.

And there’s something about the 4th, isn’t there, that makes people thirsty? Stock up on organic beer like Peak or Wolaver’s. Or, if you’re mixing cocktail pitchers for your guests, try these tasty recipes for sustainable white wine sangria, vodka watermelon, pisco sour, watermelon martini, joie de Veev, strawberry mojito, and margarita popsicles.

…and be merry
There’s been some talk lately about whether or not such a thing as a “green” fireworks display exists. Let’s talk about that. We all love to see the sparks fly and feel that heavy boom in the pit of our stomachs, but explosives are explosives are explosives. No matter how you package your perchlorate—whether in eco-sinful steel and fiberglass mortars, plastic cartridges, or “environmentally friendly” cardboard and paper mache vessels—blowing up toxic explosives in the sky is just never going to be healthy for the water, soil, or people it rains down on.

As a more sustainable alternative to fireworks, let your inner child loose and make your own ruckus instead: bang pots and pans (we’re sort of kidding, but also sort of not), blow whistles, harangue a friend into playing the guitar for everyone. And sing! Remember singing? That thing people do in groups when they’re happy and want to celebrate something? If you’re a little fuzzy on the lyrics to America’s patriotic songs, give these favorites a quick skim: The Star Spangled Banner, God Bless America, America the Beautiful, This Land is Your Land. The words are more inspiring than you remembered, right? Did you get a chill? Let’s keep America beautiful and free.

But unlike many reptile species, which produce more females when the nests are warmer, tuatara eggs tend to hatch more males when temperatures rise.

According to a new study, this means that that warmer temperatures caused by global warming will unfairly skew tuatara populations toward the male gender in just a few decades, and ultimately doom them to extinction.

Direct descendents of the dinosaurs, only two tuatara species remain (Sphenodon punctatus and Sphenodon guntheri) in existence in New Zealand, where they live on just a few small islands off the country's coast. Their habitats offer few opportunities to move to cooler areas. The population on North Brother Island is already male-heavy, although scientists don't know yet if this gender imbalance has been caused by climate change.

Now, for the most part, I've always gardened for fun, for the exercise, and for my mental health, but I've added another reason to the list: I hope to reduce our "food miles" -- the distance required to transport food from farm fields in the U.S. or abroad to our dinner plates. Bringing the Food Economy Home: Local Alternatives to Global Agribusiness authors Helena Norberg-Hodge, Todd Merrifield, and Steven Gorelick suggest, "A typical plate of food in the U.S. has accumulated some 1500 miles from source to table." What's more, "The average distance we now drive to shop for food each year is 898 miles." That's a lot of miles, but others say it's one's food-related carbon footprint which matters most. Sometimes it's hard to know just which practices are the greenest. One thing I know for sure: growing and preserving one's own fresh produce is assuredly the tastiest.

Green Toys sand bucket, castle mold, fork and shovel made in the U.S. from recycled #2 milk jugs, now on sale for $16.95 at Kangarooboo.com

For picnics, lightweight, reusable bright plastic cups, plates, bowls and cutlery, plus a big sturdy collander that could alternate as a sand sifter, are made from recycled #5 plastic by Recycline.  To children, things always taste best in miniature portions and dishes, like this Green Toys setting for 4 with utensils, plates, bowls, cups, a frypan and covered casserole. There's also a tea party set for when the mad hatter, doormouse and friends stop by, both from recycled milk jugs, at Greenfeet.com .

And even though they're not plastic, we couldn't resist these classic wooden toy sailboats that will float in tide pool, bath tub or sandcastle moat.