The UN reported in 2006 that cow poops, farts and belches were a significant contributor to global warming. The culprit is the digestive system of cows and their propensity for lots of poop and frequent belching. Scientists from around the world quickly conducted studies to control the livestock emissions of methane. While research is still underway, many answers have been found and some new frontiers forged to use the abundant supply of renewable cow pies as alternative energy.
The UN report disclosed that cows and other livestock contribute 18% of global greenhouse gas emissions --- "more than all the planes, trains and automobiles on the planet." The 18% represents the cumulative contribution from raising livestock, such as fertilizer production as well as transportation:
Burning fuel to produce fertiliser to grow feed, to produce meat and to transport it - and clearing vegetation for grazing - produces 9 per cent of all emissions of carbon dioxide, the most common greenhouse gas. And their wind and manure emit more than one third of emissions of another, methane, which warms the world 20 times faster than carbon dioxide.
Livestock belching alone accounts for 5% of global greenhouse gas emissions. The belch from a single cow may emit 25-130 gallons a day of methane.
The EPA reports that globally our livestock produce 80 million metric tons of methane annually, which is 28% of global methane emissions and 20% of US methane emissions.
Governments have taken the UN belching report quite seriously, spending lots of money on studies from scientists around the world and there have even been demands on EU to "stop cows and sheep PARPING" with laws.
Scientists quickly uncovered that most of the cow emissions come from belching rather than farting. Researchers believe the level of belched methane is connected to the food eaten:
Methane is generated in the stomachs of ruminants, such as cows and sheep, as bacteria breaks down plant fibres. The gas is emitted into the atmosphere when the animals belch as they chew cud. Almost all the methane released by cows comes out through the mouth.
Japanese researchers may have found a way to stop cows from belching methane:
Supplementing the animals' diet with cysteine, a type of amino acid, and nitrate can reduce the methane produced by the animals, the researchers say.... The team found that feeding the animals cysteine in addition to nitrate not only significantly cut the methane they generate, but also helped prevent them from being poisoned.
Researchers also found a causal connection between nitrate and the amount of methane belched: "[D]airy cattle that consume a large amount of nitrate from grass growing in soil treated with high levels of chemical fertiliser release only traces of methane when they belch."
The key to reduction is to create a more digestible diet that reduces methane production in the gut so that there is less belching or at least gas free belching. Some researchers suggest that a diet of "rye grass with a high sugar content, white clover and bird’s-foot trefoil, a traditional meadow flower also known as 'bacon and eggs'" may be effective.
Now that belching is deemed a major contributor of global warming, a Swedish university received $672,000 to "measure the amount of greenhouse gases released when cows belch." The study will provide different diets to cows, which will be outfitted with a collar to measure the methane when they belch.
Cow farts produce less methane than belching, but researchers have "estimated that a single cow can emit 100 to 200 liters of methane per day."
Not all farts are bad. If cows could start farting like kangaroos, global warming can be reduced. Kangaroo have special bacteria in their stomachs that apparently produces methane-free farts. Thus, Australian scientists are now working to give cattle and sheep a kangaroo-like stomach. The kangaroo stomach is also more environmentally friendly because the bacteria permit a more efficient digestive system, which means less feed and less water due to obtaining "10 to 15 per cent more energy out of the feed they are eating."
Greenpeace takes it one step further, urging people to eat cute little Skippy. It's one thing to reduce or replace red meat consumption with chicken and fish to prevent land-clearing while cutting down on farting and belching livestock, but eating Skippy!
Cornell researchers may have a reprieve for Skippy! In the first study to examine land requirements for diets or food prints, the researchers concluded that a low-fat vegetarian diet is very efficient in terms of how much land is needed to produce the food. However, a diet with a little meat and dairy products uses less land than many vegetarian diets.
The reason is that fruits, vegetables and grains must be grown on high-quality cropland, he explained. Meat and dairy products from ruminant animals are supported by lower quality, but more widely available, land that can support pasture and hay.
Sounds like scientists are fast resolving the belching and farting methane emissions, but what about the cow pies which produce methane as bacteria breaks down the manure. The US has 100 million cattle. "A well-fed dairy cow produces 120 pounds of manure every day, or 40,000 pounds per year per animal."
Well, now the vast supply of renewable cow pies is being turned into energy.
In California, Pacific Gas and Electric Company teamed up in 2007 with BioEnergy Solutions to deliver renewable cow pie energy that will service the electricity needs of 50,000 residential customers through the use of methane digesters.
BioEnergy Solutions' first project will be Vintage Dairy, which is located in Fresno County, California. Manure from the farm's 3,000 dairy cows will be flushed into covered lagoons that will trap the methane gas produced as the manure decomposes. The methane will be "scrubbed" to remove carbon dioxide and corrosive materials to meet PG&E's industry leading environmental standards for power plants, then delivered to PG&E through the utility's pipeline. PG&E will use the natural gas to deliver renewable electricity to its customers in central and northern California.
This is not the first use of methane digesters. In 2004, Marin County dairy farmer Albert Straus used poop from his 270 cows to generate electricity for his farm and electric car by using a methane digester to break down the manure.
The farmer has a utility shed, which contains a 75-kilowatt generator and an electrical panel that regulates power originating from a poop-filled lagoon that feeds into PG&E's electric power grid. The cost for the methane digester system was a nice $280,000, however, the monthly savings of $5,000-6,000 will permit payment of his investment in only a few years.
Legislation helped to pave the path for more farms to use methane digesters:
While the technology for farm-based methane production has been around for two decades, economics and resistance from the utility industry have prevented all but a handful of California farmers from transforming their animal waste into energy.
While there are 1,950 commercial dairies in operation in California -- which leads the nation in the production of milk and cheese -- and nearly 2 million dairy cows, Straus' methane digester is only the fifth now operating in the state.
But thanks to two pieces of recent legislation, 13 additional methane systems are now under construction, and renewable-energy advocates predict that scores more are sure to follow. The Straus project is the first of 14 methane projects to receive matching funds from the California Energy Commission, one result of the rolling blackouts that plagued the state during the summer of 2001.
The beauty of the cow pie energy is the use of an abundance of poop that would otherwise create environmental problems. So, what about dog and cat poop? A San Francisco company likes the idea of turning a ton of pet poop into 50 gallons of fuel. 6,500 tons of cat and dog poop are produced every year in the Bay Area, which could translate into 325,000 gallons of fuel instead of ending up in landfills or polluting beaches.
"If you took one ton of a degradable material, dog poop and food scraps together, you could produce 50 gallons of liquid fuel," Reed said. "If you took 80 tons of this material, you could produce enough energy to produce [power for] a thousand homes."
In the case of pet poop, the poop is ground up into a manufactured biomass, which is fed into a digester machine which converts the poop into methane gas. "Burning that gas produces energy in the form of electricity, natural gas and liquefied natural gas." The methane would be used to "power equipment that normally runs on natural gas, such as a kitchen stove or a heater."
This just shows what may be accomplished when the global community works together. But, heh, gotta wonder, whose poop will next be turned into renewable energy?