Composite Lumber: Okay or Not?

 

 

Hey Mr. Green,

I belong to the Cool Cities group Cool Joliet. We have a controversy over raised beds in a community garden. Should we use cedar wood or composite lumber for the beds? Composite timbers are a blend of wood fiber and UV-protected polypropylene,  100% recycled material, and the connecting joints made of durable ABS plastic resin. Will plastic leach toxic material into the soil, or is the composite better because it is all recycled and will last longer? --Lorna, Joliet, Illinois

While raised beds are a great idea, there are far better uses for cedar, such as furniture, armoires, and chests (cedar actually deters moths). Although cedar is rot resistant, if put in contact with the ground it will eventually decay and need replacement. (Of course I’m for easing up on the cedars in general, except in cases where they are invasive species. The famous cedars of Lebanon were among the first victims of deforestation, when the macho ur-logger Gilgamesh went furiously whacking them down more than 4500 years ago, as revealed in the Epic of Gilgamesh.)

Composite lumber is a greener choice for raised beds. In addition to being made of recycled material, the composite’s polypropylene and the ABS in the brackets will not leach toxic substances into the soil because they are considered safe for many applications—polypropylene even for baby bottles. In fact, the USDA organic farming certification program allows composite lumber for beds or fencing, in contrast to some types of treated wood, which is taboo if it’s too near to the crops. Composite lumber is also slow to deteriorate, as I can testify from use of it in my own raised beds.

Finally, congratulations to you guys in Joliet on joining the Cool Cities program. Those in other towns who might want to emulate your efforts, see http://www.coolcities.us/ .

 

 

Feed Waterfowl, or Leave Them Be?

Hey Mr Green,

I understand that human food is no good for our waterfowl. I watch as families come down to the nearby pond with bags of leftover bread and proceed to give it to the birds. Since they are unlikely to change this habit, is there  any healthier food for waterfowl that I could recommend people to feed these birds? --Joe, West Hempstead, New York

Feeding waterfowl is bad for the birds and bad for the environment, according no less an authority than my fellow bird-lovers at the Audubon Society. Leftovers, bread, cookies, etc. can make waterfowl sick because it’s not their natural diet. Worse yet, feeding lures way too many birds to congregate in the same place, which pollutes water with excess bird manure, and ruins vegetation that other critters need. Also, when the waterfowl are too crowded the situation can start to resemble those notorious confined animal feeding operations where chickens and pigs persecute each other by pecking and tail-biting (a problem that is rather inhumanely solved by snipping the beak tip and docking the tail). Female ducks in overcrowded areas even wind up in care centers after gang-rapes by drakes driven crazy by unnatural crowding.

Then there’s the wild dignity of these wonderful birds. Instead of being on the move, in the wild, and foraging as they have for millennia, they become sedentary domesticated layabouts waiting for us humans to rain down the manna of junk food. Such coddling may even damage the wild population by enabling weak birds to pass defects into the gene pool.

But if you can’t talk folks out of feeding the fowl, the next best option is to convince them to leave the bread and cookies at home, and dispense only cracked corn or “all-purpose” (also called “triple duty”) poultry and waterfowl feed. The latter is closer to their natural diet, with a mix of protein, fat, fiber, and various nutrients essential to avian health. To find feed dealers nearest you who sell cracked corn or all-purpose feed, go to http://www.albersfeed.com/ or http://www.purinamills.com/ 

Is Recycling Cans and Bottles Worth It?

Hey Mr. Green,

How far does it pay to transport recyclables for recycling before the transport makes it not efficient? Answer for: glass, plastic, metal. Our desert community has to send its recyclables a long way to get them processed. 

 –-Dennis, Ridgecrest, California

In the best of all possible worlds, we’d be reusing returnable bottles instead of recycling them, in accord with the old saw, “reduce, reuse, and recycle,” where “reduce” and “reuse” are the better choices. But I doubt that we’ll be returning to returnables anytime soon, as a substantial recycling infrastructure is now in place.

Nevertheless, recycling beats heck out of dumping. Any reduction in the waste stream is beneficial. Besides the energy saved by recycling and its reduction of global warming gas, there are also the substantial advantages of reduced litter and reduced need to build new dumps to hold the billions containers that get tossed every year. Anyway, in many places the dumps themselves are a substantial distance from the municipalities they serve. And speaking of service, in the U.S., we operate twice as many garbage trucks as municipal buses, according to the environmental group INFORM’s study of how we deal with a staggering 250 million tons of refuse to the dumps each year. This is probably reason enough to reduce the waste stream.

Recycling is worthwhile for your town because the energy saved by using recycled instead virgin material exceeds the energy needed to haul your bottles to the nearest recycling outfits. Glass recycling still yields a net energy savings despite fairly long transportation.

Here’s why: The glass recycling companies closest to your town are, as you say, rather distant—about 160 miles. One company manager says he typically receives 25 tons of bottles on semis with open trailers like the kind that haul demolition rubble. Recycled glass saves more than 2 million British thermal units per ton in glassmaking, according to the EPA, or over 50 million Btus for that single truckload of bottles. A truck hauling bottles at a typical 6 miles per gallon would burn about 27 gallons of diesel fuel, which contains about 3.7 million British thermal units. So the long-distance transportation energy is still way lower than the energy that can be saved—about 14 times less. (Of course if the truck doesn’t do any backhaul, the savings are cut in half because of the return trip.) So even for a long trip there’s still a reasonable energy savings.

The savings per ton are higher for plastic and metal, with 22.3 million Btus per ton for plastic; 20.5 per ton for steel, and 185.5 million Btu per ton for aluminum, according to EPA

Beverage container recycling, while a very valuable and essential activity, is really a form of mining for raw materials to make products that have been foisted on consumers by the container and beverage industries. These guys make throwaways that you diligently return to them, whether you’re putting them out for the “miners” collecting at your curb, or you’re a homeless guy mining his ore from a garbage can to sell to . The clean little secret is we’d be better off with refillable bottles like those used before throwaways took over in the 1950s. Even a study done for the glass manufacturer Owens Illinois reports that refillable bottles’ carbon footprint is so small that it didn’t bother to put refillables in its graphs comparing throwaway glass, aluminum, and plastic containers. Researchers found that a refillable bottle, if used 30 times, has only 3.5 percent of the carbon emission impact of a single-use glass bottles even if the single-use bottle is made with 25 percent recycled glass, and the refillable has a somewhat lower level emissions compared with aluminum or plastic bottles. 

 

Electric Cars: Green, But No Magic Solution

Hey Mr. Green,

The cover story in Sierra asks, “Can we really get off oil in 20 years?” As long as Mr. Green claims “EVs can be responsible for releasing almost as much CO2 as a 40-mpg car” the answer will be “of course not.” The Nissan Leaf, not unlike EV conversions driven for years, has a 99 miles-per-gallon-equivalent EPA rating. Further, the same amount of gasoline used to power a combustion vehicle, if burned in a conventional power plant, can put six electric vehicles (EVs) on the road.

--Bob, Grants Pass, Oregon

Don’t get me wrong. EVs are greener than conventional cars, but beware of naive enthusiasm about the environmental blessings of EVs. An EV is only as clean as the source of its electric power, and even if it runs on 100 percent clean energy, the EV can do little to ease a host of environmental problems caused by an ever-increasing number of cars, regardless of their power supply.

The way this “equivalent” mpg rating gets presented is itself an example of the overly rosy view of EVs. The mpg rating you cite is misleading, if not downright deceptive, because it is correct only if the EV derives all its electricity from sources that don’t use fossil fuel to create electric power. Yes, the Nissan Leaf does travel 99 miles on the equivalent of the energy in a gallon of gasoline, or about 115,000 British thermal units, or 33.7 kilowatt hours of electric power. But these numbers do not reflect the large amount of additional energy required if fossil fuel is burned to generate that electrical power. This “hidden” energy isn’t reflected in the 99-mpg number.

The reason is that when its electricity is generated by fossil fuel, the EV is, in effect, being powered by fossil fuel, not by some morally superior electricity from a virginal source. When fossil fuels generate the EV’s electricity, there is a loss of energy, because fossil-fuel-powered dynamos are typically 35 or 40 percent efficient. This means that the electrical energy an EV uses from the fossil-fuel-powered plant equals only 35 or 40 percent of the fuel energy burned in the plant. Therefore it could actually take as much as 10,000 Btus to create your kilowatt hour of electricity (3414 Btus), meaning that in reality your Leaf needs the equivalent of around 335,000 Btus for its electricity, or the energy contained not in one gallon of gas, but in 2.9 gallons. So in real fossil-fuel-energy equivalents, the Leaf gets around 35 miles per gallon. This makes it obvious that burning the gasoline used by one conventional car in a power plant couldn’t possibly power six EVs, unless they were micro-vehicles with passengers of considerably less heft than our current population.

Still, EVs beat conventional cars because 1) it’s easier to control pollution from a few thousand power plants than from 250 million vehicles 2) EVs don’t require motor oil, or ooze out other toxic fluids, and 3) EVs can be powered by clean sources of energy, though it will be years before such energy is widely available.

Like all environmentalists, I’d love to see the world “get off oil” and other fossil fuels because of the immense damage caused by extracting them (e.g., mountaintop mining, oil spills), not to mention the homicidal depravity and insane waste of fighting wars to secure petroleum. But let’s not make a fetish of EV technology, as has been our habit in bowing down before technological miracles” that turned out to have some dicey unintended consequences.

Many of same old problems caused by our irrational dependence on automobile transportation would persist even if all cars were EVs rolling over the asphalt and concrete on “clean” energy. We're driving 105 million more vehicles on 200,000 more miles of roads than 35 years ago, on a paved area that already exceeds 60,000 square miles, 7,500 of which are dedicated just to parking, according to the federal government and the Environmental Policy Institute). Nor are EVs likely to diminish the immense personal grief and public-health problems caused by highway fatalities and injuries. Moreover, even clean energy doesn’t come without an environmental price to pay in building power lines and siting windmills and solar installations on the land. For all these reasons, if EVs  end up encouraging more driving by giving a green dispensation to cars, they could turn out to be a dubious blessing.