Dear EarthTalk: Wouldn"t a return to installing bidets in bathrooms at home go a long way toward cutting disposable tissue use and saving forests?
—Peter K., Albany, GA
Besides being more sanitary than toilet tissue, bidets—those squirty accessories so popular in Europe, Japan and elsewhere that clean your underside using a jet of water—are also much less stressful on the environment than using paper.
Justin Thomas, editor of the website metaefficient.com, considers bidets to be "a key green technology" because they eliminate the use of toilet paper. According to his analysis, Americans use 36.5 billion rolls of toilet paper every year, representing the pulping of some 15 million trees. Says Thomas: "This also involves 473,587,500,000 gallons of water to produce the paper and 253,000 tons of chlorine for bleaching." He adds that manufacturing requires about 17.3 terawatts of electricity annually and that significant amounts of energy and materials are used in packaging and in transportation to retail outlets.
To those who say that bidets waste water, advocates counter that the amount is trivial compared to how much water we use to produce toilet paper in the first place. Biolife Technologies, manufacturer of the high-end line of Coco bidets, says the amount of water used by a typical bidet is about 1/8th of a gallon, with the average toilet using about four gallons per flush. Lloyd Alter of the website treehugger.com reports that making a single roll of toilet paper requires 37 gallons of water, 1.3 kilowatt/hours (KWh) of electricity and some 1.5 pounds of wood. Thomas points out that toilet paper is also a public nuisance in that it clogs pipes and adds a significant load onto city sewer systems and water treatment plants.
"Basically, the huge industry of producing toilet paper could be eliminated through the use of bidets," offers Thomas, who has been testing different toilet-seat mounted units for the past two years. He would like to someday pair a bidet with a composting sawdust toilet for the ultimate green bathroom experience.
Once reserved for Europeans, bidets are now popular all over the world—except in North America. Thomas reports that 60 percent of Japanese households today have high-tech bidets made by Toto called Washlets, while some 90 percent of Venezuelan homes have bidets. Most people use a small amount of paper to dry their posteriors after the bidet has done its job, but more expensive air-drying models dispense with the need for paper altogether. Thomas adds that bidets provide important health benefits such as increased cleanliness and "the therapeutic effect of water on damaged skin (think rashes or hemorrhoids)."
On the public health front, bidet maker BioRelief reports that almost 80 percent of all infectious diseases are passed on by human contact and that only about half of us actually wash our hands after using the facilities—making hands-free bidets a safer alternative all around. "If you don"t have to use your hands at all then there is less chance of passing or coming in contact with a virus," claims the company. BioRelief"s full featured BidetSpa sells for $549, but Lloyd Alter reports that consumers willing to go without heated water and air-drying mechanisms can get a perfectly adequate one they can install themselves for less than $100, such as the Blue Bidet, which retails for just $69.
Dear EarthTalk: What is "vertical farming" and how is it better for the environment?
— Jonathan Salzman, New York, NY
"Vertical farming" is a term coined by Columbia University professor of environmental health and microbiology Dickson Despommier to describe the concept of growing large amounts of food in urban high-rise buildings—or so-called "farmscrapers."
According to the vision first developed in 1999 by Despommier and his students, a 30-story building built on one city block and engineered to maximize year-round agricultural yield—thanks largely to artificial lighting and advanced hydroponic and aeroponic growing techniques—could feed tens of thousands of people. Ideally the recipients of the bounty would live in the surrounding area, so as to avoid the transport costs and carbon emissions associated with moving food hundreds if not thousands of miles to consumers.
"Each floor will have its own watering and nutrient monitoring systems," Despommier elaborated to online magazine Miller-McCune.com, adding that every single plant"s health status and nutrient consumption would be tracked by sensors that would help managers ward off diseases and increase yield without the need for the chemical fertilizers and pesticides so common in traditional outdoor agriculture.
"Moreover, a gas chromatograph will tell us when to pick the plant by analyzing which flavenoids the produce contains," Despommier said. "It"s very easy to do
These are all right-off-the-shelf technologies. The ability to construct a vertical farm exists now. We don’t have to make anything new."
With world population set to top nine billion by 2050 when 80 percent of us will live in cities, Despommier says vertical farming will be key to feeding an increasingly urbanized human race. His Vertical Farm Project claims that a vertical farm on one acre of land can grow as much food as an outdoor farm on four to six acres. Also, vertical farms, being indoors, wouldn"t be subject to the vagaries of weather and pests.
"The reason we need vertical farming is that horizontal farming is failing," Despommier told MSNBC, adding that if current practices don"t change soon, humanity will have to devote to agriculture an area bigger than Brazil to keep pace with global food demand. Another benefit of vertical farming is that former farmland could be returned to a natural state and even help fight global warming. As agricultural land becomes forest and other green space, plants and trees there can store carbon dioxide while also serving as habitat for wildlife otherwise displaced by development.
Vertical farming is not without critics, who argue that the practice would use huge amounts of electricity for the artificial lights and machinery that would facilitate year-round harvests. Bruce Bugbee, a Utah State University crop physiologist, believes that the power demands of vertical farming—growing crops requires about 100 times the amount of light as people working in office buildings—would make the practice too expensive compared to traditional farming where the primary input, sunlight, is free and abundant. Proponents argue that vertical farms could produce their own power by tapping into local renewable sources (solar, wind, tidal or geothermal) as well as by burning biomass from crop waste.
CONTACT: The Vertical Farm Project.
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