Wikipedia Definitions of Biodegradable, Compostable, Sustainable and Cellulose

Compostable

A compostable material biodegrades substantially under specific composting conditions. It is metabolized by the microorganisms, being incorporated into the organisms or converted into humus. The size of the material is a factor in determining compostability, and mechanical particle size reduction can speed the process. Large pieces of hardwood may not be compostable under a specific set of composting conditions, whereas sawdust of the same type of wood may be. Some biodegradable materials are only compostable under very specific conditions, usually with an industrial process.

Compost is a combination of decomposed plant and animal materials and other organic materials that are being decomposed largely through aerobic decomposition into a rich black soil. The process of composting is simple and practiced by individuals in their homes, farmers on their land, and industrially by industries and cities.

Compost soil is very rich soil and used for many purposes. A few of the places that it is used are in gardens, landscaping, horticulture, and agriculture. The compost soil itself is beneficial for the land in many ways, including as a soil conditioner, a fertilizer to add vital humus or humic acids, and as a natural pesticide for soil. In ecosystems, compost soil is useful for erosion control, land and stream reclamation, wetland construction, and as landfill cover.

Biodegradable

Biodegradable materials are capable of being broken down under the action of microorganisms into carbon dioxide, water and biomass. It may take a very long time for some material to biodegrade depending on its environment (e.g. wood in an arid area versus paper in water). Many contaminating materials not dealt with in common composting are in fact "biodegradable", and may be dealt with via bioremediation, or other special composting approaches.

Cellulose

Cellulose is the structural component of the primary cell wall of green plants, many forms of algae and the oomycetes. Some species of bacteria secrete it to form biofilms. Cellulose is the most common organic compound on Earth. About 33 percent of all plant matter is cellulose (the cellulose content of cotton is 90 percent and that of wood is 50 percent).

For industrial use, cellulose is mainly obtained from wood pulp and cotton. It is mainly used to produce paperboard and paper; to a smaller extent it is converted into a wide variety of derivative products such as cellophane and rayon. Converting cellulose from energy crops into biofuels such as cellulosic ethanol is under investigation as an alternative fuel source.

Cellulose is the major constituent of paper, paperboard, and card stock and of textiles made from cotton, linen, and other plant fibers.

Sustainable

Sustainability is the capacity to endure. In ecology, the word describes how biological systems remain diverse and productive over time. For humans, it is the potential for long-term maintenance of wellbeing, which in turn depends on the wellbeing of the natural world and the responsible use of natural resources.

Sustainability has become a wide-ranging term that can be applied to almost every facet of life on Earth, from local to a global scale and over various time periods. Long-lived and healthy wetlands and forests are examples of sustainable biological systems. Invisible chemical cycles redistribute water, oxygen, nitrogen and carbon through the world's living and non-living systems, and have sustained life for millions of years. As the earth’s human population has increased, natural ecosystems have declined and changes in the balance of natural cycles has had a negative impact on both humans and other living systems.

There is abundant scientific evidence that humanity is living unsustainably, and returning human use of natural resources to within sustainable limits will require a major collective effort. Ways of living more sustainably can take many forms from reorganising living conditions (e.g., ecovillages, eco-municipalities and sustainable cities), reappraising economic sectors (permaculture, green building, sustainable agriculture), or work practices (sustainable architecture), using science to develop new technologies (green technologies, renewable energy), to adjustments in individual lifestyles that conserve natural resources.