The Scoop on Cat Litter

Hey Mr. Green,
What is the greenest kitty litter for my indoor cat? --Carol (submitted via e-mail)

Cats themselves are a much bigger environmental menace than kitty litter. They're an invasive species that kills hundreds of millions of birds and mammals each year, robbing food from native predators like hawks and owls. So I salute you for keeping your feline where it belongs: inside.

The greenest cat litter is made of recycled paper, followed by sawdust, wheat chaff, oat hulls, or other biological materials. But more than half the litter in the United States is made of bentonite--a stripmined clay that leads right to Dick Cheney, which may explain why he raked around in Iraq like it was his personal litter box. Halliburton, where Cheney was CEO, produces about one-sixth of the 3 million tons of bentonite sold each year, of which 1.7 million tons go into cat litter. Quite a waste of a substance that can be used in iron smelting, environmental cleanup, and wine clarifying.

Neither bentonite nor silica gel litter should be flushed en masse, as they can gum up plumbing, but flushing a few particles probably won't cause trouble. Most municipal sewage systems can handle pet waste, but it should not be flushed where sea otters live, since studies have found some of these animals to be infected with toxoplasmosis, a parasitic disease carried in cat feces. Because this parasite can severely harm human embryos, pregnant women should avoid handling cat waste.

Saving Money with Solar Power?

Hey Mr. Green,
If I were to put solar panels on my home, would it be cost-effective? I see most solar panels in hot climates, and Ohio can be very cold. I live on a five-acre tract and have the option of wind turbines also. --Sherry in Dayton, Ohio

It may get cold in Dayton, but that doesn't mean you don't get sun. In fact, you get 80 percent as much sunlight in a year as Sacramento, California, whose municipal utility is a leader in solar development.
First, consider the low-tech route: efficiency. The average U.S. household consumes 11,000 kilowatt-hours per year, when many could get by on half as much. Eliminate waste by turning off lights and appliances when not in use, for example, and you could slash your energy costs with no investment.

Wherever you live, take a look at returns over the long haul. At $9 a watt, which is the typical cost in your region, a solar energy system large enough to generate power for an average household would cost roughly $80,000 after rebates and tax credits (or less in areas with stronger incentive programs). In Ohio, as in most states, if you generate more than you use, your excess power feeds into the electricity grid and you earn credit for it, allowing you to draw out as much as you put in--for free.

Still, it would take about 30 years for you to break even, assuming the utility rate goes up 4 percent a year and you put money saved from your energy bills into tax-deferred investments. But you'd keep more than 260 tons of greenhouse gases out of the atmosphere over the life of the system.

Once you nail down the cost per watt for solar, contact wind power dealers and see how their costs compare. It's hard to be more specific about wind power because there's so much variation, depending on windmill height and local topography. You might also consider systems that combine wind and solar if wind blows much harder in the winter than in the summer. These hybrid systems take advantage of seasonal variation. Meanwhile, be thankful that Big Oil hasn't privatized the sun and forced us to pay for it right down to the last photon.

Flushing Out Alternative Toilets

Hey Mr. Green,

There are a lot of folks who live outside urban areas and have private wells and septic systems. How green are these?  Doesn't this essentially recycle the water we consume and flush?

--J. Lennon in Wake Forest, North Carolina

More than 20 percent of the country's households use septic systems. They are the basic choice where there is no municipal sewage system, although I suppose a composting toilet is the ultimate green sewer machine (some are even designed to capture the methane from the waste to burn in stoves). To be on the cutting edge of sludge, you can explore various models on the internet.

Of course, septic tanks have to be pumped out periodically and should be set up to avoid the risks of health problems or water pollution. But if they’re properly designed and installed, I don't see a problem. Since some of the tanks’ water seeps back into the ground, they actually do recycle. For a wealth of information, visit the EPA's website. Your tax dollars at work!

Whatever system you're on, flush minimally so as not to waste water. In my long-ago farm childhood, we had an old outdoor toilet. It was a used model, its wooden walls laced with graffiti so vivid that it jump-started my literary career. When we finally obtained the long-anticipated indoor alternative, my father enforced minimal flushing because of his concern that the well would go dry. With water, as with everything else, the old-timers practiced reduce, reuse, and recycle long before that phrase became an axiom.

Other water-conservation tools that could be used, whether you live in the middle of nowhere or the middle of Manhattan, are: low-flow toilets, restricted-flow showerheads, aerator screens on faucets, smaller lawns and minimal lawn watering, drip irrigation, use of native plants instead of thirsty exotics, and washing machines and dishwashers run with full loads only. (And yes, a modern dishwasher uses a lot less water than a typical hand-washing process.) It goes without saying that you should make sure no faucets leak.

Some people even collect rainwater and use "gray water" (from showers and laundry) on their gardens. But if you attempt these measures, make sure there aren't toxic materials on your roof or in gutters that would contaminate the water – and that the gray water is safe for your plants.

A Real or Fake Christmas Tree: Which is Greener?

Hey Mr. Green,

Have you reached a conclusion on the real tree vs. artificial Christmas tree debate?

--Kathy in Winston Salem, North Carolina

I have indeed. The real tree is better for the environment than the fake tree. A real tree is a renewable resource, whereas a fake tree is usually made from plastic, which is derived from oil, a nonrenewable resource. The real tree can be recycled as mulch, compost, or wildlife shelter, whereas the fake tree can’t. The real tree does not contain harmful chemicals, whereas fake trees are often made with plastic polyvinyl chloride, whose manufacture releases highly toxic material. Plus, lead may have been added to stabilize the plastic. The real tree also absorbs carbon dioxide while it grows, doing its bit to fight global warming.
 
The belief that using real trees causes deforestation is mistaken. The fact is, real trees are farmed, often on marginal land that can't be used for other purposes.
 
I see only two disadvantages to real trees: First, since they have to be shipped from a tree farm each year, real trees require a lot more shipping energy than the one-time shipment of a fake tree that will be used for an average of nine years before being dispatched to the landfill. Though about 85 percent of fake trees are made in China, and thus shipped farther than real trees, they require considerably less energy to ship.

The other problem with real trees is that many farmers use pesticides on them. It’s doubtful, though, that these cause more environmental problems than the petrochemical stew from which fake trees are confected.
Both of these problems can be ameliorated by either buying a tree from a source as local as possible or by buying an organic tree. Find trees closest to home at www.christmastree.org.

There is a third option: a live tree, which you keep in a pot and bring forth with glad tidings to decorate each holiday season. This would seem to be the best choice of all. But don't get a live tree unless: a) you’re absolutely sure it’s a species well-adapted to your climate, and b) you are plant-savvy and dedicated enough to take proper care of it. In my long years of horticultural observation, I've encountered more dead live trees than living live trees.

A final point: I'm for buying the tree as late as possible. This is because, first of all, dealers tend to lower the prices to unload them late in the game, which has great appeal to people as cheap as me. Also, because the frenzied consumerist buildup to the holidays gives me the willies, early tree-purchasing seems more like a celebration of shopping than of anything cosmic or miraculous.

Unsafe at Any Speed

Hey Mr. Green,

Regarding your comment that safety features in cars add "only" 125 pounds to car weight, I remind you that an additional 100 pounds of car weight can reduce the mileage by up to 2 percent.

 –Sally in Newport News, Virginia

Hey Sally,

I'm well aware that 100 pounds can reduce mileage by 1 to 2 percent and have said so before.

But what's up with all you guys leaping to defend automakers from the menacing Mr. Green? My point was that 100 or so extra pounds is trivial compared to an additional 1,000-plus pounds. The auto barons piled that tonnage onto huge new petrol-guzzlers named for natural disasters and military raids, aggressively marketing aggressive vehicles to consumers unlikely to buy efficient cars.

The size factor was just another symptom of Detroit’s indefensible rapacity and stupidity, which got us into deep trouble during the mid-1970 fuel shortages because it wasn't making efficient cars. But the auto bosses learned nothing, repeated the same mistake, and went for a quick profit, with the result that they now face a 16-lane economic crash and are holding out their hubcaps begging for a bailout. I certainly hope the industry can be saved somehow, because I don’t want to see a couple million workers lose their jobs because of their bosses' incompetence. But we should all contact our senators and representatives demanding that they implement and enforce strict energy-efficiency requirements on the auto industry as a condition for financial help that comes from taxpayers. Otherwise, the same mistakes will be made again 30 years or so down the road.

Myth of the Little SUV Debunked

Hey Mr. Green,
I was very disappointed in your answer to the recent question about whether cars get lower gas mileage because of safety or antipollution devices. Your answer was these devices do not add weight to cars or reduce mileage. What are you talking about? At least admit that pollution-control devices like the catalytic converter impair good mileage.

I had a '90s Subaru Loyale that got more than 35 miles to the gallon, even after it was eight years old! My new Honda CRV, which I admit is a little bigger, can hardly get 22 miles per gallon, and I consider myself a good driver! –Carl in Bannockburn, United Kingdom

Hey Carl,
Your comparison actually proves my point about auto companies' stupid, inefficient giantism. Your Honda is more than a "little bigger" than the Subaru: It's a whopping one-third bigger. The Honda CRV weighs a half ton more and has at least 50 more horsepower. The CRV has a curb weight of about 3,500 pounds and a horsepower of 166, whereas the old Loyale wagon had a curb weight of around 2,400 and a horsepower of 90 or 115, depending on the type of engine. The difference in gas mileage is a result of that extra heft and oomph.

(Note: I call giantism "stupid" because Detroit is now in the same mess it was in 35 years ago. That's when car sales plunged because it had no efficient vehicles to offer during the gas crunch. You'd think that the old boys who run GM and Ford would have some recollection of this disastrous event.)

Why Even Small Carbon Footprints Matter

Hey Mr. Green,
I've heard that humans account for only 3 percent of global carbon emissions, with the rest coming from volcanoes, forest fires, and plant decay. Is this true, and if so, how can reducing our carbon footprint make an appreciable difference to the global situation? –Cary in Atlanta, Georgia

Hey Cary,
Three percent may not sound like much, but if that small percent isn't reabsorbed each year, it keeps accumulating until you have a much bigger percent and a real problem. Think of it this way: If you only gain 3 percent in weight a year, it's not much. But if you never shed that weight, you'll balloon from a 135-pound lightweight-boxer to a full-size heavyweight (albeit a rather flabby one) in 20 years.

The natural world is estimated to emit a grand total of 770.3 billion tons of CO₂ annually. Millions of life forms on land, from bacteria to elephants, pump out 440 billion tons of CO₂, while the oceans release another 330 billion tons, and volcanoes add 300 million each year. Human activity, primarily from burning fossil fuel, but also from agriculture and forest burning and clearing, accounts for "only" 32.3 billion tons, New Scientist reports.

When to Replace Lightbulbs

Hey Mr. Green,
I know fluorescent lightbulbs are more efficient than incandescents. In terms of overall resource use, however, is it better to replace a functioning incandescent bulb now or wait until it burns out? --Tom (submitted by e-mail)

I salute you for wondering about what goes into industrial processes. Some people chirp about a "postindustrial" era as if their toys were birthed by an invisible techno-god--rather than a polluting, energy-burning, all-too-earthly system.

Anyway, replace incandescents now. The resources used to produce either kind of lightbulb represent a fraction (as little as one percent, according to researchers at the Technical University of Denmark) of the bulb's overall toll on the environment. Powering the bulb in your home uses far more energy.

Parts Per Million vs. Price Per Gallon

Hey Mr. Green,
How shall we endure headlines about fuel costs at the expense of headlines about increasing atmospheric CO2? Does the public recognize "385 ppm of carbon dioxide" as well as it recognizes "$4 per gallon"? --Marvin in Glencoe, Maine

Most of us relate more easily to a $60 bill at the gas pump than parts per million, or ppm, of global-warming gases. Just look at history: Driving habits have changed largely in response to pain at the pump--not because of the growing body of knowledge about problems from tailpipe emissions. In the late 1970s and '80s, when gas prices represented an all-time high percentage of household income, gasoline consumption plummeted 12 percent. But in the following decade, as gas costs became a smaller percentage of household income, even the doubling of cars' fuel economy didn't keep demand from rising year after year.

While vehicle miles traveled and gas consumption have declined in recent years, Americans still burn 50 billion gallons more motor fuel per year, have 100 million more vehicles on the road, and drive them an average of 3,000 miles farther annually than we did three decades ago.

Podcast: Electric Cars

"Hey Mr. Green: Is there a practical electric car a person of moderate means can buy and operate?"

Click here to listen to the answer! You can also subscribe to Mr. Green's podcast.