aggregate[Classe]
géographie de la Terre (fr)[Thème]
non-renewable resource (nf.)
A non-renewable resource is a natural resource which cannot be reproduced, grown, generated, or used on a scale which can sustain its consumption rate, once depleted there is no more available for future needs. Also considered non-renewable are resources that are consumed much faster than nature can create them. Fossil fuels (such as coal, petroleum, and natural gas), nuclear power (uranium) and certain aquifers are examples. Metals are prime examples of non-renewable resources. In contrast, resources such as timber (when harvested sustainably) are considered renewable resources.
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Natural resources such as coal, petroleum (crude oil) and natural gas take thousands of years to form naturally and cannot be replaced as fast as they are being consumed. Eventually natural resources will become too costly to harvest and humanity will need to find other sources of energy.
At present, the main energy source used by humans are non-renewable fossil fuels, as a result of continual use since the first internal combustion engine in the 17th century, the fuel is still in high demand with conventional infrastructure and transport which are fitted with the combustion engine. The continual use of fossil fuels at the current rate will increase global warming and cause more severe climate change.
The use of nuclear technology requires a radioactive fuel. Uranium ore is present in the ground at relatively low concentrations and mined in 19 countries.[2] The uranium resource is used to create plutonium,[3] uranium-238 is fissionable and is transmuted into fissile plutonium-239 in a nuclear reactor. Nuclear fuel is used for the production of nuclear weapons and in nuclear power stations to create electricity.
Nuclear power provides about 6% of the world's energy and 13–14% of the world's electricity.[4] The expense of the nuclear industry remains predominantly reliant on subsidies and indirect insurance subsidies to continue.[5][6] Nuclear technology is a volatile and contaminating source of fuel production, with elements that are unstable and each decays radioactively into other elements. Nuclear power facilities produce about 200,000 metric tons of low and intermediate level waste (LILW) and 10,000 metric tons of high level waste (HLW) (including spent fuel designated as waste) each year worldwide.[7]
The use of nuclear fuel and the radioactive waste the nuclear industry collects is highly hazardous to people and wildlife. Radiocontaminants in the environment become bioaccumulative by entering the food chain,[8] internal or external exposure causes mutagenic DNA breakage, producing teratogenic generational birth defects, cancers and other damages. The United Nations (UNSCEAR) estimated in 2008 that average annual human radiation exposure includes 0.01 mSv (milli-Sievert) from the legacy of past atmospheric nuclear testing plus the Chernobyl disaster and the nuclear fuel cycle, along with 2.0 mSv from natural radioisotopes and 0.4 mSv from cosmic rays; all exposures vary by location.[9] Some radioisotopes in nuclear waste emit harmful radiation for the prolonged period of 4.5 billion years or more,[10] and storage has risks of containment. The storage of waste, health implications and dangers of radioactive fuel continue to be a topic of debate, resulting in a controversial and unresolved industry.
The nuclear fuel cycle, unlike burning fossil fuels, produces carbon dioxide emissions from production, construction and transport, between being mined, milled, enriched, formed into fuel rods, used in the power station, then stored or reprocessed, including nuclear decommissioning and management of nuclear waste, all these actions produce carbon emissions contributing significantly to global warming.[11]
Natural resources, called renewable resources, are replaced by natural processes and forces persistent in the natural environment. There are intermittent and reoccurring renewables, and recyclable materials, which are utilised during a cycle across a certain amount of time, and can be harnessed from any number of cycles.
The production of goods and services by manufacturing products in economic systems creates many types of waste, during production and after the consumer has made use of it. The material is then either incinerated, buried in landfill or used again and recycled. There are materials that are biodegradable and others that require sustainable design to be recycled. Life-cycle assessments are used to assess the environmental impacts associated with any stage of a product's life. Recycling turns materials of value, that would otherwise become waste into valuable resources again.
The natural environment, with soil, water, forests, plants and animals are all renewable resources, as long as they are adequately monitored, protected and conserved. Sustainable agriculture is the study and operation of production that preserves plant and animal ecosystems for cultivation over the long-term. The overfishing of the oceans is one instance, where an industry practice or method can threaten an ecosystem and increase endangered species, controlling whether conditions are suitable for a fishery to recover and sustain human consumption. An unregulated industry practice or method can lead to a complete resource depletion.[12]
The renewable energy from the sun, wind, wave, biomass and geothermal energies are based on renewable resources. Renewable resources such as the movement of water (hydropower, tidal power and wave power), wind (used for wind power) and radiant energy from geothermal heat (used for geothermal power) and solar energy (used for solar power) are practically infinite and cannot be depleted, unlike their non-renewable counterparts, which are likely to run out if not used sparingly.
The potential wave energy on coastlines can provide 1/5 of world demand. Hydroelectric power can supply 1/3 of our total energy global needs. Geothermal energy can provide 1.5 more times the energy we need. There is enough wind to power the planet 30 times over, wind power could power all of humanity's needs alone. Solar currently supplies only 0.1% of our world energy needs, but there is enough out there to power humanity's needs 4,000 times over, the entire global projected energy demand by 2050.[13][14]
Renewable energy and energy efficiency are no longer niche sectors that are promoted only by governments and environmentalists. The increasing levels of investment and that more of the capital is from conventional financial actors, both suggest that sustainable energy has become mainstream and the future of energy production, as non-renewable resources decline. This is reinforced by climate change concerns, nuclear dangers and accumulating radioactive waste, high oil prices, peak oil and increasing government support for renewable energy. These factors are commercializing renewable energy, enlarging the market and growing demand, the adoption of new products to replace obsolete technology and the conversion of existing infrastructure to a renewable standard.[15]
In economics, a non-renewable resource is defined as goods, where greater consumption today implies less consumption tomorrow.[16] David Ricardo in his early works analysed the pricing of exhaustible resources, where he argued that the price of a mineral resource should increase over time. He argued that the spot price is always determined by the mine with the highest cost of extraction, and mine owners with lower extraction costs benefit from a differential rent. The first model is defined by Hotelling's rule, which is a 1931 economic model of non-renewable resource management by Harold Hotelling. It shows that efficient exploitation of a nonrenewable and nonaugmentable resource would, under otherwise stable conditions, lead to a depletion of the resource. The rule states that this would lead to a net price or "Hotelling rent" for it that rose annually at a rate equal to the rate of interest, reflecting the increasing scarcity of the resources. The Hartwick's rule provides an important result about the sustainability of welfare in an economy that uses non-renewable source.
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