Resource depletion occurs when a natural resource is consumed faster than it can be replenished. The value of a resource depends on its availability in nature and the cost of extracting it. By the economic law of supply and demand, the scarcer the resource the more valuable it becomes. There are several types of resource depletion, including but not limited to: wetland and ecosystem degradation, soil erosion, aquifer depletion, and overfishing. The depletion of wildlife populations is called defaunation.
It is a matter of research and debate how humanity will be impacted and what the future will look like if resource consumption continues at the current rate, and when specific resources will be completely exhausted.
History of resource depletion
The depletion of resources has been an issue since the beginning of the 19th century amidst the First Industrial Revolution. The extraction of both renewable and non-renewable resources increased drastically, much further than thought possible pre-industrialization, due to the technological advancements and economic development that lead to an increased demand for natural resources.
Although resource depletion has roots in both colonialism and the Industrial Revolution, it has only been of major concern since the 1970s. Before this, many people believed in the "myth of inexhaustibility", which also has roots in colonialism. This can be explained as the belief that both renewable and non-renewable natural resources cannot be exhausted because there is seemingly an overabundance of these resources. This belief has caused people to not question resource depletion and ecosystem collapse when it occurred, and continues to prompt society to simply find these resources in areas which have not yet been depleted.
Depletion accounting
In an effort to offset the depletion of resources, theorists have come up with the concept of depletion accounting. Related to 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 by countries to estimate the adjustments needed due to their use and depletion of the natural capital available to them. Natural capital refers to 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 for 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 the 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.
Importance
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 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.
Issues
Depletion accounting is complex to implement as nature is not as quantifiable as 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 the "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 depletion
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.Materials Flow and Sustainability, US Geological Survey.Fact Sheet FS-068-98, June 1998.
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:
Oil, conventional (2005) Oil, all liquids (2017). Old expectation: Gasoline (2023) Copper (2017). Old expectation: Copper (2024). Data from the United States Geological Survey (USGS) suggest that it is very unlikely that copper production will peak before 2040. Coal per KWh (2017). Old expectation per ton: (2060) 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:
Aluminium (2057) Iron (2068) Such projections may change, as new discoveries are made and typically misinterpret available data on Mineral Resources and Mineral Reserves. Phosphor (2048). The last 80% of world reserves are only one mine.
Peak minerals marks the point in time when the largest production of a mineral will occur in an area, with production declining in subsequent years. While most mineral resources will not be exhausted in the near future, global extraction and production has become more challenging.Mudd, G M, 2010, The Environmental Sustainability of Mining in Australia: Key Mega-Trends and Looming Constraints. Resources Policy, . Miners have found ways over time to extract deeper and lower grade ores with lower production costs. More than anything else, declining average ore grades are indicative of ongoing technological shifts that have enabled inclusion of more 'complex' processing – in social and environmental terms as well as economic – and structural changes in the minerals exploration industry and these have been accompanied by significant increases in identified Mineral Reserves.
Peak minerals The concept of peak minerals offers a useful model for representing the changing impacts associated with processing declining resource qualities in the lead up to, and following, peak mineral production in a particular region within a certain time-frame.Giurco, D., Prior, T., Mudd, G., Mason, L. and Behrisch, J. (2009). Peak minerals in Australia: a review of changing impacts and benefits. Prepared for CSIRO Minerals Down Under Flagship, by the Institute for Sustainable Futures (University of Technology, Sydney) and Department of Civil Engineering (Monash University), March 2010.
Peak minerals provides an analytical framework within which the economic, social and environmental trajectories of a particular mining industry can be explored in relation to the continuing (and often increasing) production of mineral resources. It focuses consideration on the change in costs and impacts associated with processing easily accessible, lower cost ores before peak production of an individual mine or group of mines for a given mineral. It outlines how the economy might respond as processing becomes characterised by higher costs as the peak is approached and passed. Issues associated with the concept of peak minerals include: Average processed ore grades are in global decline for some minerals whilst production is increasing. Average discovered ore grades (e.g., in porphyry copper deposits) have remained remarkably steady over the last 150 years. Structural changes in the minerals exploration industry and the recent focus on "brownfields" exploration Mining is extending to deeper, more remote deposits. Individual mines or mining provinces can eventually become exhausted, though changes in demand and mining technology can act to prolong their productive lives.
Resource depletion and recoverability
Giurco et al. (2009)Giurco, D., Evans, G., Cooper, C., Mason, L. & Franks, D. (2009) "Mineral Futures Discussion Paper: Sustainability Issues, Challenges and Opportunities". Institute for Sustainable Futures, UTS and Sustainable Minerals Institute, University of Queensland. indicate that the debate about how to analytically describe resource depletion is ongoing. Traditionally, a fixed stock paradigm has been applied, but Tilton and Lagos (2007)Tilton, J. & Lagos, G. (2007) "Assessing the long-run availability of copper." Resources Policy, 32, 19–23 suggest using an opportunity cost paradigm is better because the usable resource quantity is represented by price and the opportunity cost of using the resource. Unlike energy minerals such as coal or oil – or minerals used in a dissipative or metabolic fashion like phosphorusCordell, D., Drangert, J.-O. & White, S. (2009) "The story of phosphorus: Global food security and food for thought". Global Environmental Change, 19, 292–305. – most non-energy minerals and metals are unlikely to run out. Metals are inherently recyclable and more readily recoverable from end uses where the metal is used in a pure form and not transformed or dissipated; in addition, metal ore is accessible at a range of different grades. So, although metals are not facing exhaustion, they have become more challenging to obtain in the quantities that society demands, and the energy, environmental and social cost of acquiring them could constrain future increases in production and usage.
Cheap and easy in the past; costly and difficult in future Peak production poses a problem for resource rich countries like Australia, which have developed a comparative advantage in the global resources sector, which may diminish in the future. The costs of mining, once primarily reflected in economic terms, are increasingly being considered in social and environmental terms, although these are yet to meaningfully inform long-term decision-making in the sector. Such consideration is particularly important if the industry is seeking to operate in a socially, environmentally and economically sustainable manner into the next 30–50 years.
Benefits from dependence on the resource sector