Composting

Composting is the decomposition of plant remains and other once-living materials to make an earthy, dark, crumbly substance that is excellent for enriching garden soil. It is one way to recycle your yard and kitchen wastes, reduce the volume of garbage you send to landfills and live a more sustainable life. When I lived in San Francisco, the city kindly collected food scraps (including meat and fat which really cannot be composted in your backyard) for composting. When I moved to the country in Virginia I had to rethink my approach to composting and recycling.

Your approach to composing to a large extent will be dictated by how large your yard is. If you live in a small lot suburban or urban environment that does not collect your kitchen scraps, then you will have to utilize a rodent proof and enclosed method of composting. There are basically three enclosed methods of composting which can be used for interior, garage or small yard/patio composting.

Bokashi is a method of intensive composting that can be used inside your home. Kitchen waste is placed into a container which can be sealed with an air tight lid to contain the smell. Kitchen scraps are layered with a Bokashi carrier which is usually wheat bran, rice hulls or saw dust that has been inoculated with composting micro-organisms. When using this method, it is best to have more than one container and to fill the second while the bacteria in the first are completing their work.

Vermiculture is the method of composting using worms. Worm composting typically uses a commercial worm bin (though you can always build your own shallow, sealed bin). Bedding material must be used, typically, shredded newspaper that has been moistened. A handful or two of soil, ground limestone, or well-crushed eggshells every couple of months is good for providing grit and calcium. You fill the bin with moistened bedding, toss in a few handfuls of soil, and add the worms and food scraps. Various species of worms can be used, but red worms are sold for the purpose (at least around here). They seem to survive well in these systems. Be sure to keep your worm composter at moderate temperatures, which basically requires keeping it in the garage.

The Sierra Club recommends a sealed drum composters if you have some outdoor space. These systems are rotating drums of various sizes. To achieve a good carbon to nitrogen ratio it is recommended that 50/50 balance of brown dry materials and green wet materials are added by weight. Brown materials include leaves, dry grass, shredded newspaper, and other natural products. Green materials include fruit and vegetable peels, egg shells, coffee grinds, and green plant trimmings. You simply rotate the drum three times a week during warm weather to ensure perfect mix and proper air circulation. When the weather is freezing do not turn the drum. You can watch the short composting video at this link.

Because I have acres of land and woods I have the luxury of utilizing the lazy girl’s methods of composting. The most basic and passive form of composting is backyard mulching. The largest amount of green waste generated at the suburban home is from the garden. Grass clippings should never be collected and sent to a landfill, your are just throwing away nutrients for your lawn. The first step in mulching is to take the grass clippings collector off of your lawnmower. By leaving the clippings on the ground, they will decompose and add nutrients to the soil, improving the quality of your yard. I combine mulching with not fertilizing my yard, since the grass clippings contain similar nutrients. This way I am being “green” and “sustainable” by doing less.

There are two ways to mulch leaves and this depends on the density of trees in your yard. You can either collect the leaves or spread them evenly on soil-exposed areas, to ultimately produce rich topsoil. If the layer of leaves is light, use the lawnmower to shred the leaves to help their decomposition and leave them. If leaves are collected and placed in a pile, make sure to moisten several layers of the pile to help them decompose more quickly.

Passive composting requires that you have both a carbon source and a nitrogen source and that bacteria develop. The bacteria develop naturally and the desired carbon to nitrogen ratio is about 30 to 1 that is approximated by a 50:50 mixture by weight according to some sources and 3 to 1 by weight according to the U.S. EPA. Composting is not an exact science and getting close enough will work. Good carbon sources are dried leaves, bark, shredded news paper or cardboard. Nitrogen sources are raw or cooked plant waste. The following is a list of compostable household waste; cardboard rolls, clean paper, coffee grounds and filters, cotton rags, dryer and vacuum cleaner lint (but only natural fibers), eggshells, fireplace ashes, fruits and vegetables, small amounts of grass clippings, hair and pet fur, hay and straw, houseplants, leaves, nut shells, sawdust, shredded newspaper, and tea bags (pull out the little staples and discard separately).

For your compost pile you need to layer carbon source with nitrogen source into a large pile. This pile can be left open or placed into a bin. It is then left to sit as the organic matter begins to rot. Over time (around 1 to 3 years depending on your carbon and nitrogen ratio, material size, temperature and aeration), the material will have decomposed into a rich compost material that is great for use as topsoil. Turning the pile is believed to speed up the decomposition, but certainly releases the stink. Modern composting guides suggest using smaller homogeneous sized bits of waste, shredded paper if enough dried leaves are not available to keep the carbon to nitrogen ratio (brown leaves, bark and paper to green moist waste) at 30 to 1 and monitoring the moisture level.

The vegetative waste management and yard waste composting regulations in Virginia allow composting of leaves, grass, brush and other collected material, but not composting of land-clearing debris. For an individual homeowner, Virginia pretty much leaves you alone unless you become a nuisance to your neighbors or a health hazard.

If you have a large enough yard you can either follow the traditional methods or the slightly more active approach of the early organic movement (the writings of Howard and Balfour are recommended if you are interested), suggesting that a layered pile in a temperate damp climate will do just fine with minimal effort and if you are willing to wait a couple of years and have lots of land to spare you can take my approach and build layered compost pile in edge of the woods each year and then leave it and start a new one. Time will ultimately take care of missing the ideal ratio, cold weather, failure to toss regularly with a pitch fork and most other failings.

What Is the Product Carbon Content and is it Useful

The recent announcement of the partnership between the Environmental Defense Fund and Wal-Mart has once more raised the issue of product carbon content. Lately, it has been popular to measure sustainability by the individual and national carbon footprint. Carbon dioxide is a by product of combustion, all combustion. Human beings exhale it at over 3 pounds per day for the average sedentary adult. Carbon dioxide is also released when we burn fossil fuels such as gas, coal or oil to produce electricity, move vehicles, manufacture products etc. In a natural carbon cycle, carbon dioxide is used by plants and trees. However, the carbon dioxide in the atmosphere has been rising. Carbon dioxide content in the atmosphere has risen from approximately 250 parts per million (0.025%) to 386 part per million (0.039%) in the past 100 years. This increase has been attributed by many to human activity. The belief is that we are producing more carbon dioxide than can be absorbed by the plants and trees because we are burning too much fuel. The certainty of the direct relationship between global temperature and carbon dioxide concentrations has been called into question in the most recent revelations of manipulated data from the Climate Research Unit (CRU) at the University of East Anglia and the revelations of unsubstantiated claims from the United Nations Intergovernmental Panel on Climate Change.

The popular belief is that this increase in carbon dioxide in the atmosphere has caused the 1 degree Fahrenheit increase in average global temperature since 1900. It was postulated that burning fossil fuels for industry and power was the direct cause of this increase, though other contributing causes might exist. The methods used to determine global average temperature has come into question with the data manipulation disclosures from the CRU at the University of East Anglia, so currently, there is no consensus on what the global average temperature actually is. Nonetheless, the popular climate change theory postulates that the overall temperature of the planet is increasing (global warming) at a faster rate now and causing the earth’s climate to change in unpredictable ways (from floods and hurricanes to heat waves and droughts). The strongest adherents to this belief hold that the burning of fossil fuels must be reduced immediately. The belief is that if we could reduce our carbon dioxide emissions enough we could stop the climate of the earth from changing.

At the height of the Global Warming movement regulators and universities began to calculate the carbon dioxide released when making, shipping and using various products. These were only estimates, depending on some of the assumptions; drastically different totals could be reached. This concept was jumped on by merchants and manufacturers, to advertise a scheme to save the planet thought guided acquisition-purchase enough of the right things and save the planet. The makers of everything from milk to jackets to cars were estimating the carbon dioxide released when making, shipping and using of their products and advertising the results. These were called carbon content labels. For companies looking to get their products carbon labeled, three carbon labeling services are currently in the market. The labels are available in the UK and US and require a processed-based life-cycle analysis (LCA) to be carried out, usually in the price range of $10,000-$20,000 depending on the product. The methods of estimating the carbon content contained a large number of estimates, guesses and assumptions making this calculation easily manipulated and practically worthless for true allocation of resources because it only estimated the generalized cost of a product in terms of energy used in its life cycle. These labels at best are only broad generalizations and may not be particularly useful in evaluating choices for a sustainable life because of the underlying use assumptions as well. While it is very important to reduce the burning or fossil fuels and increase the planting of trees; we should approach this goal as only one aspect of sustainable living.

The fashion for carbon labels may simply fade away and soon be forgotten. Questions remain about how carbon footprints should be measured and whether putting such figures on the label is practical or something shoppers will even care about. Carbon labels beg for a recommended (or mandated) daily allowance for carbon. Building a bureaucracy to ensure that carbon dioxide in each product is measured at a cost of $10,000-$20,000, and potentially develop a recommended daily carbon allowance without a well documented connection between carbon allowance level and sustainable living is simply wasteful. Given the nature of the carbon cycle; how does one create a sustainable and accurate carbon budget?

Another method suggested has been to purchase carbon offsets for all products. The world's biggest carbon offset market, the Kyoto Protocol's clean development mechanism (CDM), is run by the UN, administered by the World Bank, and is intended to reduce emissions by rewarding developing countries that invest in clean technologies. According to David Victor, of Stanford University, as many as two-thirds of the supposed "emission reduction" credits being produced by the CDM from projects in developing countries are not backed by real reductions in pollution. In fact, in the February 2010 Harpers’ Magazine spelled out inconsistencies, questionable practices, and potential fraud in the CDM market raising the possibility emission reductions credits are increasing CO2 emissions behind the guise of promoting sustainable development. Even when a CDM credit does represent an "emission reduction", there is no global benefit because offsetting is a "zero sum" game.

The approach currently underway at Wal-Mart may hold more promise. There is real benefit to increasing the efficiency in energy use by selecting efficient technologies in everyday life. There is tremendous benefit to improving insulation in buildings and homes, and passive use of solar and wind. Improving manufacturing practices and farming practice to reduce energy consumption and utilization of pesticides and protect water supplies will yield ecological benefits, but may or may not reduce CO2 emissions. Changes in how and where we live; urban dweller, rural dweller, suburban dweller; whether or not we commute or if we commute using public or private transportation, alone or in a groups, our purchasing and activity choices all will impact our carbon use. Carbon content labels do not give the individual tools to evaluate a purchase choice against not purchasing, which is an important aspect of any decision. However, carbon content only looks at one aspect of the carbon cycle and fails to consider the other resources of the earth. At this point it is unlikely that the labeling of carbon content in products will be mandated. Legislating the measurement of carbon dioxide release in all things will cost money and resources and of itself will not make our lives more sustainable, but will certainly add costs to all things.