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Resource depletion is the consumption of a resource faster than it can be replenished. Natural resources are commonly divided between renewable resources and non-renewable resources (see also mineral resource classification). Use of either of these forms of resources beyond their rate of replacement is considered to be resource depletion. The value of a resource is a direct result of its availability in nature and the cost of extracting the resource, the more a resource is depleted the more the value of the resource increases. There are several types of resource depletion, the most known being: Aquifer depletion, deforestation, mining for fossil fuels and minerals, pollution or contamination of resources, slash-and-burn agricultural practices, Soil erosion, and overconsumption, excessive or unnecessary use of resources.
In an effort to offset the depletion of resources, theorists have come up with depletion accounting. Better known as 'green accounting,' depletion accounting aims to account for nature's value on an equal footing with the market economy. Resource depletion accounting uses data provided from countries to estimate the adjustments needed due to their use and depletion of the natural capital available to them. Natural capital are natural resources such as mineral deposits or timber stocks. Depletion accounting factors in several different influences such as the number of years until resource exhaustion, the cost of resource extraction and the demand of the resource. Resource extraction industries make up a large part of the economic activity in developing countries. This, in turn, leads to higher levels of resource depletion and environmental degradation in developing countries. Theorists argue that implementation of resource depletion accounting is necessary in developing countries. Depletion accounting also seeks to measure the social value of natural resources and ecosystems. Measurement of social value is sought through ecosystem services, which are defined as the benefits of nature to households, communities and economies.
There are many different groups interested in depletion accounting. Environmentalists are interested in depletion accounting as a way to track the use of natural resources over time, hold governments accountable or to compare their environmental conditions to those of another country. Economists want to measure resource depletion to understand how financially reliant countries or corporations are on non-renewable resources, whether this use can be sustained and the financial drawbacks of switching to renewable resources in light of the depleting resources.
Depletion accounting is complex to implement as nature is not as quantifiable like cars, houses or bread. For depletion accounting to work, appropriate units of natural resources must be established so that natural resources can be viable in the market economy. The main issues that arise when trying to do so are, determining a suitable unit of account, deciding how to deal with "collective" nature of a complete ecosystem, delineating the borderline of the ecosystem and defining the extent of possible duplication when the resource interacts in more than one ecosystem. Some economists want to include measurement of the benefits arising from public goods provided by nature, but currently there are no market indicators of value. Globally, environmental economics has not been able to provide a consensus of measurement units of nature's services.
Minerals are needed to provide food, clothing, and housing. A United States Geological Survey (USGS) study found a significant long-term trend over the 20th century for non-renewable resources such as minerals to supply a greater proportion of the raw material inputs to the non-fuel, non-food sector of the economy; an example is the greater consumption of crushed stone, sand, and gravel used in construction.
Large-scale exploitation of minerals began in the Industrial Revolution around 1760 in England and has grown rapidly ever since. Technological improvements have allowed humans to dig deeper and access lower grades and different types of ore over that time. Virtually all basic industrial metals (copper, iron, bauxite, etc.), as well as rare earth minerals, face production output limitations from time to time, because supply involves large up-front investments and is therefore slow to respond to rapid increases in demand.
Minerals projected by some to enter production decline during the next 20 years:
- Gasoline (2023)
- Copper (2024). Data from the United States Geological Survey (USGS) suggest that it is very unlikely that copper production will peak before 2040.
- Zinc. Developments in hydrometallurgy have transformed non-sulfide zinc deposits (largely ignored until now) into large low cost reserves.
Minerals projected by some to enter production decline during the present century:
Peak oil is the period when the maximum rate of global petroleum extraction is reached, after which the rate of production will undergo a long-term decline. The 2005 Hirsch report concluded that the decreased supply combined with increasing demand will significantly increase the worldwide prices of petroleum derived products, and that most significant will be the availability and price of liquid fuel for transportation.
The Hirsch report, funded by United States Department of Energy, concluded that “The peaking of world oil production presents the U. S. and the world with an unprecedented risk management problem. As peaking is approached, liquid fuel prices and price volatility will increase dramatically, and, without timely mitigation, the social, economic and political costs will be unprecedented. Viable mitigation options exist on both the supply and demand sides, but to have substantial impact, they must be initiated more than a decade in advance of peaking.”
Deforestation is the clearing of forests by cutting or burning of trees and plants in a forested area. As a result of deforestation,recently about one half of the forests that once covered Earth have been destroyed. It occurs for many different reasons, and it has several negative implications on the atmosphere and the quality of the land in and surrounding the forest.
One of the main causes of deforestation is clearing forests for agricultural reasons. As the population of developing areas, especially near rainforests, increases, the need for land for farming becomes more and more important. For most people, a forest has no value when its resources are not being used, so the incentives to deforest these areas outweigh the incentives to preserve the forests. For this reason, the economic value of the forests is very important for the developing countries.
Because deforestation is so extensive, it has made several significant impacts on the environment, including:
- Carbon dioxide in the atmosphere
- Changing the water cycle
- An increase in soil erosion
- A decrease in biodiversity
Deforestation is often cited as a contributor to global warming. Because trees and plants remove carbon dioxide and emit oxygen into the atmosphere, the reduction of forests contribute to about 12% of anthropogenic carbon dioxide emissions. One of the most pressing issues that deforestation creates is soil erosion. The removal of trees causes higher rates of erosion, increasing risks of landslides, which is a direct threat to many people living close to deforested areas. As forests get destroyed, so does the habitat for millions of animals. It is estimated that 80% of the world's known biodiversity lives in the rainforests, and the destruction of these rainforests is accelerating extinction at an alarming rate.
The United Nations and the World Bank created programs such as Reducing Emissions from Deforestation and Forest Degradation (REDD), which works especially with developing countries to use subsidies or other incentives to encourage citizens to use the forest in a more sustainable way. In addition to making sure that emissions from deforestation are kept to a minimum, an effort to educate people on sustainability and helping them to focus on the long-term risks is key to the success of these programs. The New York Declaration on Forests and its associated actions promotes reforestation, which is being encouraged in many countries in an attempt to repair the damage that deforestation has done.
Wetlands are ecosystems that are often saturated by enough surface or groundwater to sustain vegetation that is usually adapted to saturated soil conditions, such as cattails, bulrushes, red maples, wild rice, blackberries, cranberries, and peat moss. Because some varieties of wetlands are rich in minerals and nutrients and provide many of the advantages of both land and water environments they contain diverse species and provide a distinct basis for the food chain. Wetland habitats contribute to environmental health and biodiversity.  Wetlands are a nonrenewable resource on a human timescale and in some environments cannot ever be renewed. Recent studies indicate that global loss of wetlands could be as high as 87% since 1700 AD, with 64% of wetland loss occurring since 1900. Some loss of wetlands resulted from natural causes such as erosion, sedimentation, subsidence, and a rise in the sea level.
Wetlands provide environmental services for:
- Food and habitat
- Improving water quality
- Commercial fishing
- Floodwater reduction
- Shoreline stabilization
Resources in wetlands
Some of the world's most successful agricultural areas are wetlands which have been drained an converted to farmland for large-scale agriculture. Large-scale draining of wetlands also occurs for real estate development and urbanization. In contrast, in some cases wetlands are also flooded to be converted to recreational lakes or hydro-power generation. In some countries ranchers have also moved their property onto wetlands for grazing due to the nutrient rich vegetation. Wetlands in Southern America also prove a fruitful resource for poachers, as animals with valuable hides such a jaguars, maned wolves, caimans and snakes are drawn to wetlands. The effect of the removal of large predators is still unknown in South African wetlands.
Humans benefit from wetlands in indirect ways as well. Wetlands act as natural water filters, when runoff from either natural or man-made processes pass through, wetlands can have a neutralizing effect. If a wetland is in between an agricultural zone and a freshwater ecosystem, fertilizer runoff will be absorbed by the wetland and used to fuel the slow processes that occur happen, by the time the water reaches the freshwater ecosystem there won't be enough fertilizer to cause destructive algal blooms that poison freshwater ecosystems.
Non-natural causes of wetland degradation
- Hydrologic alteration 
- Urbanization and urban development
- Industrialization and industrial development
- Silviculture/Timber harvest
- Atmospheric deposition
To preserve the resources extracted from wetlands, current strategies are to rank wetlands and prioritize the conservation of wetlands with more environmental services, create more efficient irrigation for wetlands being used for agriculture and restricting access to wetlands by tourists.
Water is an essential resource needed to survive everyday life. Historically, water has had a profound influence on a nation's prosperity and success around the world. Groundwater is water that is in saturated zones underground, the upper surface of the saturated zone is called the water table. Groundwater is held in the pores and fractures of underground materials like sand, gravel and other rock, these rock materials are called aquifers. Groundwater can either flow naturally out of rock materials or can be pumped out. Groundwater supplies wells and aquifers for private, agricultural, and public use and is used by more than a third of the world's population every day for their drinking water. Globally there is 22.6 million cubic kilometers of groundwater available and only .35 million of that is renewable.
Groundwater as a non-renewable resource
Groundwater is considered to be a non-renewable resource because less than six percent of the water around the world is replenished and renewed on a human timescale of 50 years. People are already using non-renewable water that is thousands of years old, in areas like Egypt they are using water that may have been renewed a million years ago which is not renewable on human timescales. Of the groundwater used for agriculture 16 to 33% is non-renewable. It is estimated that since the 1960s groundwater extraction has more than doubled, which has increased groundwater depletion. Due to this increase in depletion, in some of the most depleted areas use of groundwater for irrigation has become impossible or cost prohibitive.
Overusing groundwater, old or young can lower subsurface water levels and dry up streams, which could have a huge effect on ecosystems on the surface. When the most easily recoverable fresh groundwater is removed this leaves a residual with inferior water quality. This is in part from induced leakage from the land surface, confining layers or adjacent aquifers that contain saline or contaminated water. Worldwide the magnitude of groundwater depletion from storage may be so large as to constitute a measurable contributor to sea-level rise.
Currently, societies respond to water-resource depletion by shifting management objectives from location and developing new supplies to augmenting conserving and reallocation of existing supplies. There are two different perspectives to groundwater depletion, the first is that depletion is considered literally and simply as a reduction in the volume of water in the saturated zone, regardless of water quality considerations. A second perspective views depletion as a reduction in the usable volume of fresh groundwater in storage.
Augmenting supplies can mean improving water quality or increasing water quantity. Depletion due to quality considerations can be overcome by treatment, whereas large volume metric depletion can only be alleviated by decreasing discharge or increasing recharge. Artificial recharge of storm flow and treated municipal wastewater, has successfully reversed groundwater declines. In the future improved infiltration and recharge technologies will be more widely used to maximize the capture of runoff and treated wastewater.
This section may stray from the topic of the article. (June 2018)
Renewable energy can be collected from renewable resources. The two main sources of renewable energy are solar energy and wind power. The government and scientists are researching and looking upon alternatives to replace the depleting nonrenewable resources. Japan and the U.S. are leading in the department of selling and manufacturing solar powered utilities.
- Höök, M.; Bardi, U.; Feng, L.; Pang., X. (2010). "Development of oil formation theories and their importance for peak oil" (PDF). Marine and Petroleum Geology. 27 (9): 1995–2004. doi:10.1016/j.marpetgeo.2010.06.005. hdl:2158/777257.
- Depletion and Conservation of Natural Resources: The Economic Value of the World's Ecosystems — How Much is Nature Worth? The Role of Forests and Habitat
- Dirzo, Rodolfo; Hillary S. Young; Mauro Galetti; Gerardo Ceballos; Nick J. B. Isaac; Ben Collen (2014). "Defaunation in the Anthropocene" (PDF). Science. 345 (6195): 401–406. doi:10.1126/science.1251817. PMID 25061202. S2CID 206555761.
- Boyd, James (15 March 2007). "Nonmarket benefits of nature: What should be counted in green GDP?". Ecological Economics. 61 (4): 716–723. doi:10.1016/j.ecolecon.2006.06.016.
- Vincent, Jeffrey (February 2000). "Green accounting: from theory to practice". Environment and Development Economics. 5: 13–24. doi:10.1017/S1355770X00000024.
- Banzhafa, Spencer; Boyd, James (August 2007). "What are ecosystem services? The need for standardized environmental accounting units" (PDF). Ecological Economics. 63 (2–3): 616–626. doi:10.1016/j.ecolecon.2007.01.002.
- Materials Flow and Sustainability, US Geological Survey.Fact Sheet FS-068-98, June 1998.
- West, J (2011). "Decreasing metal ore grades: are they really being driven by the depletion of high-grade deposits?". J Ind Ecol. 15 (2): 165–168. doi:10.1111/j.1530-9290.2011.00334.x.
- Drielsma, Johannes A; Russell-Vaccari, Andrea J; Drnek, Thomas; Brady, Tom; Weihed, Pär; Mistry, Mark; Perez Simbor, Laia (2016). "Mineral resources in life cycle impact assessment—defining the path forward". Int J Life Cycle Assess. 21 (1): 85–105. doi:10.1007/s11367-015-0991-7.
- Meinert, Lawrence D; Robinson, Gilpin R Jr; Nassar, Nedal T (2016). "Mineral Resources: Reserves, Peak Production and the Future". Resources. 5 (14): 14. doi:10.3390/resources5010014.
- Klare, M. T. (2012). The Race for What's Left. Metropolitan Books. ISBN 9781250023971.
- Valero & Valero(2010)による『Physical geonomics: Combining the exergy and Hubbert peak analysis for predicting mineral resources depletion』から
- Valero, Alicia; Valero, Antonio (2010). "Physical geonomics: Combining the exergy and Hubbert peak analysis for predicting mineral resources depletion". Resources, Conservation and Recycling. 54 (12): 1074–1083. doi:10.1016/j.resconrec.2010.02.010.
- Zinc Depletion
- Jenkin, G. R. T.; Lusty, P. A. J.; McDonald, I; Smith, M. P.; Boyce, A. J.; Wilkinson, J. J. (2014). "Ore Deposits in an Evolving Earth" (PDF). Geological Society, London, Special Publications. 393: 265–276. doi:10.1144/SP393.13. S2CID 53488911.
- Hitzman, M. W.; Reynolds, N. A.; Sangster, D. F.; Allen, C. R.; Carman, C. F. (2003). "Classification, genesis, and exploration guides for Nonsulfide Zinc deposits". Economic Geology. 98 (4): 685–714. doi:10.2113/gsecongeo.98.4.685.
- DOE Hirsch Report
- "Global Deforestation". Global Change Curriculum. University of Michigan Global Change Program. January 4, 2006
- Butler, Rhett A. "Impact of Population and Poverty on Rainforests". Mongabay.com / A Place Out of Time: Tropical Rainforests and the Perils They Face. Retrieved May 13, 2009.
- Pearce, David W (2001). "The Economic Value of Forest Ecosystems". Ecosystem Health. 7 (4): 284–296. doi:10.1046/j.1526-0992.2001.01037.x. S2CID 31139340.
- G. R. van der Werf, D. C. Morton, R. S. DeFries, J. G. J. Olivier, P. S. Kasibhatla, R. B. Jackson, G. J. Collatz and J .T. Randerson, CO2 emissions from forest loss, Nature Geoscience, Volume 2 (November 2009) pp. 737–738
- Do We Have Enough Forests? By Sten Nilsson
- "Copenhagen Accord of 18 December 2009". UNFCC. 2009. Retrieved 2009-12-28.
- Diamond, Jared Collapse: How Societies Choose to Fail or Succeed; Viking Press 2004, pages 301–302
- Foley, Jonathan A; DeFries, Ruth; Asner, Gregory P; Barford, Carol; et al. (2005). "Global Consequences of Land Use". Science. 309 (5734): 570–574. doi:10.1126/science.1111772. PMID 16040698. S2CID 5711915.
- "Major Causes of Wetland Loss and Degradation". NCSU. Retrieved 2016-12-11.
- Davidson, Nick C. (January 2014). "How much wetland has the world lost? Long-term and recent trends in global wetland area". Marine and Freshwater Research. 60: 936–941 – via ResearchGate.
- Keddy, Paul A. (2010). Wetland Ecology: Principles and Conservation. Cambridge University Press. ISBN 9780521739672.
- Kachur, Torah (2 February 2017). "Don't drain the swamp! Why wetlands are so important". CBC. Retrieved 8 April 2019.
- Peterson, Erik; Posner, Rachel (January 2010). "The World's Water Challenge". Current History. 109 (723): 31–34. doi:10.1525/curh.2010.109.723.31.
- "What is groundwater?". www.usgs.gov. Retrieved 2019-04-02.
- Chung, Emily. "Most Groundwater is Effectively a Non-renewable Resource, Study FInds". CBC News.
- "Most groundwater is effectively a non-renewable resource, study finds".
- Wada, Yoshihide; Beek, Ludovicus P. H. van; Kempen, Cheryl M. van; Reckman, Josef W. T. M.; Vasak, Slavek; Bierkens, Marc F. P. (2010). "Global depletion of groundwater resources" (PDF). Geophysical Research Letters. 37 (20): n/a. doi:10.1029/2010GL044571. hdl:1874/209122. ISSN 1944-8007.
- Konikow, Leonard F.; Kendy, Eloise (2005-03-01). "Groundwater depletion: A global problem". Hydrogeology Journal. 13 (1): 317–320. doi:10.1007/s10040-004-0411-8. ISSN 1435-0157. S2CID 21715061.
- Brown, Lester R.; Larsen, Janet; Roney, J. Matthew; Adams, Emily E. (2015). The Great Transition. New York, N.Y.: W.W. Norton & Company. pp. 67. ISBN 978-0-393-35055-5.
- Grandin, Greg, "The Death Cult of Trumpism: In his appeals to a racist and nationalist chauvinism, Trump leverages tribal resentment against an emerging manifest common destiny", The Nation, 29 Jan./5 Feb. 2018, pp. 20–22. "[T]he ongoing effects of the ruinous 2003 war in Iraq and the 2007–8 financial meltdown are... two indicators that the promise of endless growth can no longer help organize people's aspirations... We are entering the second 'lost decade' of what Larry Summers calls 'secular stagnation,' and soon we'll be in the third decade of a war that Senator Lindsey Graham... says will never end. [T]here is a realization that the world is fragile and that we are trapped in an economic system that is well past sustainable or justifiable.... In a nation like the United States, founded on a mythical belief in a kind of species immunity—less an American exceptionalism than exemptionism, an insistence that the nation was exempt from nature, society, history, even death—the realization that it can't go on forever is traumatic." (p. 21.)