Blog

Renewable resources

http://en.wikipedia.org/wiki/Renewable_resource

From Wikipedia, the free encyclopedia

Daneshill Energy Forest The UK’s largest plantation of Eucalypts, planted in 2005 by Nottinghamshire County Council.

A renewable resource is an organic natural resources that can replenish in due timecompared to the usage, either through biological reproduction or other naturally recurring processes. Renewable resources are a part of Earth’s natural environment and the largest components of its ecosphere. A positive life cycle assessment is a key indicator of a resource’s sustainability.^[1]

Definitions of renewable resources may also include agriculture production, as insustainable agriculture and to an extent water resources.^[2] In 1962 Paul Alfred Weissdefined Renewable Resources as: “The total range of living organisms providing man with food, fibres, drugs, etc…“.^[3] Another type of renewable resources is renewable energyresources. Common sources of renewable energy include solar, geothermal and wind power, which are all categorised as renewable resources.

Contents

• 1 Food and water
  • 1 Water resources
  • 2 Non agricultural food
  • 3 Sustainable agriculture
• 2 Overview of non-food resources
  • 1 Historical role
  • 2 Challenges
  • 3 Renewables used for autarky approaches
  • 4 Legal situation and subsidies
• 3 Examples of industrial use
  • 1 Bioplastics
  • 2 Bioasphalt
  • 3 Renewable energy
  • 4 Biomass
  • 5 Biofuel
  • 6 Biogas
  • 7 Natural fibre
• 4 Threats to renewable resources
  • 1 Overfishing
  • 2 Deforestation
  • 3 Endangered species

1. Food and water

1.1 Water resources

Further information: Water resources

Water can be considered a renewable material when carefully controlled usage, treatment, and release are followed. If not, it would become a non-renewable resource at that location. For example, groundwater is usually removed from an aquifer at a rate much greater than its very slow natural recharge, and so groundwater is considered non-renewable. Removal of water from the pore spaces may cause permanent compaction (subsidence) that cannot be renewed. 97.5% of the water on the Earth is salt water, and 3% is fresh water; slightly over two thirds of this is frozen in glaciers and polar ice caps.^[4] The remaining unfrozen freshwater is found mainly as groundwater, with only a small fraction (0,008%) present above ground or in the air.^[5]

Water pollution is one of the main concerns regarding water resources. It is estimated that 22% of worldwide water is used in industry.^[6] Major industrial users include hydroelectric dams, thermoelectric power plants, which use water for cooling, ore and oilrefineries, which use water in chemical processes, and manufacturing plants, which use water as a solvent.

1.2 Non agricultural food

Alaska wild “berries” from the Innoko National Wildlife Refuge – Renewable Resources

Food is any substance consumed to provide nutritional support for the body.^[7] Most food has its origin in renewable resources. Food is obtained directly from plants and animals.

Wild berries and other fruits, mushrooms, plants, seeds and naturally growing edible resources, still represent a valuable source of nutrition in many countries, especially in rural areas. in fact many wild animals are dependent on wild plants and fruits as a source of food.^[8]

Hunting may not be the first source of meat in the modernised world, but it is still an important and essential source for many rural and remote groups. It is also the sole source of feeding for wild carnivores.^[9]

1.3 Sustainable agriculture

Main article: Sustainable agriculture

The phrase sustainable agriculture was coined by Australian agricultural scientist Gordon McClymont.^[10] It has been defined as “an integrated system of plant and animal production practices having a site-specific application that will last over the long term”.^[11] Expansion of agricultural land has an impact on biodiversity and contributes to deforestation. The Food and Agriculture Organisation of the United Nations estimates that in coming decades, cropland will continue to be lost to industrial and urban development, along with reclamation of wetlands, and conversion of forest to cultivation, resulting in the loss of biodiversity and increased soil erosion.^[12]

Polyculture practices in Andhra Pradesh

Although air and sunlight are available everywhere on Earth, crops also depend onsoil nutrients and the availability of water. Monoculture is a method of growing only one crop at a time in a given field, which can damage land and cause it to become either unusable or suffer from reduced yields. Monoculture can also cause the build-up of pathogens and pests that target one specific species. The Great Irish Famine (1845–1849) is a well-known example of the dangers of monoculture.

Crop rotation and long-term crop rotations confer the replenishment of nitrogen through the use of green manure in sequence with cereals and other crops, and can improve soil structure and fertility by alternating deep-rooted and shallow-rooted plants. Other methods to combat lost soil nutrients are returning to natural cycles that annually flood cultivated lands (returning lost nutrients indefinitely) such as the Flooding of the Nile, the long-term use of biochar, and use of crop and livestock landraces that are adapted to less than ideal conditions such as pests, drought, or lack of nutrients.

Agricultural practices are the single greatest contributor to the global increase in soil erosion rates.^[13] It is estimated that “more than a thousand million tonnes of southern Africa’s soil are eroded every year. Experts predict that crop yields will be halved within thirty to fifty years if erosion continues at present rates.”^[14] The Dust Bowl phenomenon in the 1930s was caused by severedrought combined with farming methods that did not include crop rotation, fallow fields, cover crops, soil terracing and wind-breaking trees to prevent wind erosion.^[15]

The tillage of agricultural lands is one of the primary contributing factors to erosion, due to mechanised agricultural equipment that allows for deep plowing, which severely increases the amount of soil that is available for transport by water erosion.^[16][17] The phenomenon called Peak Soil describes how large-scale factory farming techniques are jeopardizing humanity’s ability to grow food in the present and in the future.^[18] Without efforts to improve soil management practices, the availability of arable soil will become increasingly problematic.^[19]

Methods to combat erosion include no-till farming, using a keyline design, growing wind breaks to hold the soil, and widespread use of compost. Chemical fertiliser and pesticides can also have an effect of soil erosion, which can contribute to soil salinity and prevent other species from growing. Phosphate is a primary component in the chemical fertiliser applied most commonly in modern agricultural production. However, scientists estimate that rock phosphate reserves will be depleted in 50–100 years and that Peak Phosphate will occur in about 2030.^[20]

Industrial processing and logistics also have an effect on agriculture’s sustainability. The way and locations crops are soldrequires energy for transportation, as well as the energy cost for materials, labour, and transport. Food sold at a local location, such a farmers’ market, have reduced energy overheads.

Illegal slash and burn practice inMadagascar, 2010