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Thursday, August 26, 2021

Nuclear power proposed as renewable energy

From Wikipedia, the free encyclopedia

Whether nuclear power should be considered a form of renewable energy is an ongoing subject of debate. Statutory definitions of renewable energy usually exclude many present nuclear energy technologies, with the notable exception of the state of Utah. Dictionary-sourced definitions of renewable energy technologies often omit or explicitly exclude mention of nuclear energy sources, with an exception made for the natural nuclear decay heat generated within the Earth.

The most common fuel used in conventional nuclear fission power stations, uranium-235 is "non-renewable" according to the Energy Information Administration, the organization however is silent on the recycled MOX fuel. Similarly, the National Renewable Energy Laboratory does not mention nuclear power in its "energy basics" definition.

In 1987, the Brundtland Commission (WCED) classified fission reactors that produce more fissile nuclear fuel than they consume (breeder reactors, and if developed, fusion power) among conventional renewable energy sources, such as solar power and hydropower. The American Petroleum Institute does not consider conventional nuclear fission renewable, but considers breeder reactor nuclear fuel renewable and sustainable, and while conventional fission leads to waste streams that remain a concern for millennia, the waste from efficiently recycled spent fuel requires a more limited storage supervision period of about thousand years. The monitoring and storage of radioactive waste products is also required upon the use of other renewable energy sources, such as geothermal energy.

Definitions of renewable energy

Renewable energy flows involve natural phenomena, which with the exception of tidal power, ultimately derive their energy from the sun (a natural fusion reactor) or from geothermal energy, which is heat derived in greatest part from that which is generated in the earth from the decay of radioactive isotopes, as the International Energy Agency explains:

Renewable energy is derived from natural processes that are replenished constantly. In its various forms, it derives directly from the sun, or from heat generated deep within the earth. Included in the definition is electricity and heat generated from sunlight, wind, oceans, hydropower, biomass, geothermal resources, and biofuels and hydrogen derived from renewable resources.

Renewable energy resources exist over wide geographical areas, in contrast to other energy sources, which are concentrated in a limited number of countries.

In ISO 13602-1:2002, a renewable resource is defined as "a natural resource for which the ratio of the creation of the natural resource to the output of that resource from nature to the technosphere is equal to or greater than one".

Conventional fission, breeder reactors as renewable

Nuclear fission reactors are a natural energy phenomenon, having naturally formed on earth in times past, for example a natural nuclear fission reactor which ran for thousands of years in present-day Oklo Gabon was discovered in the 1970s. It ran for a few hundred thousand years, averaging 100 kW of thermal power during that time.

Conventional, human manufactured, nuclear fission power stations largely use uranium, a common metal found in seawater, and in rocks all over the world, as its primary source of fuel. Uranium-235 "burnt" in conventional reactors, without fuel recycling, is a non-renewable resource, and if used at present rates would eventually be exhausted.

A cutaway model of the 2nd most powerful presently operating fast breeder reactor in the world. The (BN-600), at 600 MW of nameplate capacity is equivalent in power output to a natural gas CCGT. It dispatches 560 MW to the Middle Urals power grid. Construction of a second breeder reactor, the BN-800 reactor was completed in 2014.

This is also somewhat similar to the situation with a commonly classified renewable source, geothermal energy, a form of energy derived from the natural nuclear decay of the large, but nonetheless finite supply of uranium, thorium and potassium-40 present within the Earth's crust, and due to the nuclear decay process, this renewable energy source will also eventually run out of fuel. As too will the Sun, and be exhausted.

Nuclear fission involving breeder reactors, a reactor which breeds more fissile fuel than they consume and thereby has a breeding ratio for fissile fuel higher than 1 thus has a stronger case for being considered a renewable resource than conventional fission reactors. Breeder reactors would constantly replenish the available supply of nuclear fuel by converting fertile materials, such as uranium-238 and thorium, into fissile isotopes of plutonium or uranium-233, respectively. Fertile materials are also nonrenewable, but their supply on Earth is extremely large, with a supply timeline greater than geothermal energy. In a closed nuclear fuel cycle utilizing breeder reactors, nuclear fuel could therefore be considered renewable.

In 1983, physicist Bernard Cohen claimed that fast breeder reactors, fueled exclusively by natural uranium extracted from seawater, could supply energy at least as long as the sun's expected remaining lifespan of five billion years. This was based on calculations involving the geological cycles of erosion, subduction, and uplift, leading to humans consuming half of the total uranium in the Earth's crust at an annual usage rate of 6500 tonne/yr, which was enough to produce approximately 10 times the world's 1983 electricity consumption, and would reduce the concentration of uranium in the seas by 25%, resulting in an increase in the price of uranium of less than 25%.

Proportions of the isotopes, U-238 (blue) and U-235 (red) found in natural uranium, versus grades that are enriched. light water reactors and the natural uranium capable CANDU reactors, are primarily powered only by the U-235 component, failing to extract much energy from U-238. While by contrast uranium breeder reactors mostly use U-238/the primary constituent of natural uranium as their fuel.

Advancements at Oak Ridge National Laboratory and the University of Alabama, as published in a 2012 issue of the American Chemical Society, towards the extraction of uranium from seawater have focused on increasing the biodegradability of the process and reducing the projected cost of the metal if it was extracted from the sea on an industrial scale. The researchers' improvements include using electrospun Shrimp shell Chitin mats that are more effective at absorbing uranium when compared to the prior record setting Japanese method of using plastic amidoxime nets. As of 2013 only a few kilograms (picture available) of uranium have been extracted from the ocean in pilot programs and it is also believed that the uranium extracted on an industrial scale from the seawater would constantly be replenished from uranium leached from the ocean floor, maintaining the seawater concentration at a stable level. In 2014, with the advances made in the efficiency of seawater uranium extraction, a paper in the journal of Marine Science & Engineering suggests that with, light water reactors as its target, the process would be economically competitive if implemented on a large scale. In 2016 the global effort in the field of research was the subject of a special issue in the journal of Industrial & Engineering Chemistry Research.

In 1987, the World Commission on Environment and Development(WCED), an organization independent from, but created by, the United Nations, published Our Common Future, in which a particular subset of presently operating nuclear fission technologies, and nuclear fusion were both classified as renewable. That is, fission reactors that produce more fissile fuel than they consume - breeder reactors, and when it is developed, fusion power, are both classified within the same category as conventional renewable energy sources, such as solar and falling water.

Presently, as of 2014, only 2 breeder reactors are producing industrial quantities of electricity, the BN-600 and BN-800. The retired French Phénix reactor also demonstrated a greater than one breeding ratio and operated for ~30 years, producing power when Our Common Future was published in 1987.

To fulfill the conditions required for a nuclear renewable energy concept, one has to explore a combination of processes going from the front end of the nuclear fuel cycle to the fuel production and the energy conversion using specific fluid fuels and reactors, as reported by Degueldre et al (2019). Extraction of uranium from a diluted fluid ore such as seawater has been studied in various countries worldwide. This extraction should be carried out parsimoniously, as suggested by Degueldre (2017). An extraction rate of kilotons of U per year over centuries would not modify significantly the equilibrium concentration of uranium in the oceans (3.3 ppb). This equilibrium results from the input of 10 kilotons of U per year by river waters and its scavenging on the sea floor from the 1.37 exatons of water in the oceans. For a renewable uranium extraction, the use of a specific biomass material is suggested to adsorb uranium and subsequently other transition metals. The uranium loading on the biomass would be around 100 mg per kg. After contact time, the loaded material would be dried and burned (CO2 neutral) with heat conversion into electricity.e.g. The uranium ‘burning’ in a molten salt fast reactor helps to optimize the energy conversion by burning all actinide isotopes with an excellent yield for producing a maximum amount of thermal energy from fission and converting it into electricity. This optimisation can be reached by reducing the moderation and the fission product concentration in the liquid fuel/coolant. These effects can be achieved by using a maximum amount of actinides and a minimum amount of alkaline/earth alkaline elements yielding a harder neutron spectrum. Under these optimal conditions the consumption of natural uranium would be 7 tons per year and per gigawatt (GW) of produced electricity.e.g. The coupling of uranium extraction from the sea and its optimal utilisation in a molten salt fast reactor should allow nuclear energy to gain the label renewable. In addition, the amount of seawater used by a nuclear power plant to cool the last coolant fluid and the turbine would be ∼2.1 giga tons per year for a fast molten salt reactor, corresponding to 7 tons of natural uranium extractable per year. This practice justifies the label renewable.

Fusion fuel supply

If it is developed, fusion power would provide more energy for a given weight of fuel than any fuel-consuming energy source currently in use, and the fuel itself (primarily deuterium) exists abundantly in the Earth's ocean: about 1 in 6500 hydrogen (H) atoms in seawater (H2O) is deuterium in the form of (semi-heavy water). Although this may seem a low proportion (about 0.015%), because nuclear fusion reactions are so much more energetic than chemical combustion and seawater is easier to access and more plentiful than fossil fuels, fusion could potentially supply the world's energy needs for millions of years.

In the deuterium + lithium fusion fuel cycle, 60 million years is the estimated supply lifespan of this fusion power, if it is possible to extract all the lithium from seawater, assuming current (2004) world energy consumption. While in the second easiest fusion power fuel cycle, the deuterium + deuterium burn, assuming all of the deuterium in seawater was extracted and used, there is an estimated 150 billion years of fuel, with this again, assuming current (2004) world energy consumption.

Legislation in the United States

If nuclear power were classified as renewable energy (or as low-carbon energy), additional government support would be available in more jurisdictions, and utilities could include nuclear power in their effort to comply with Renewable portfolio standard (RES).

In 2009, the State of Utah passed the "Renewable Energy Development Act" which in part defined nuclear power as a form of renewable energy.

 

Natural resource

From Wikipedia, the free encyclopedia
 

The rainforest in Fatu-Hiva, in the Marquesas Islands, is an example of an undisturbed natural resource. Forest provides timber for humans, food, water and shelter for the flora and fauna tribes and animals. The nutrient cycle between organisms form food chains and foster a biodiversity of species.
 
The Carson Fall in Mount Kinabalu, Malaysia is an example of undisturbed natural resources. Waterfalls provide spring water for humans, animals and plants for survival and also habitat for marine organisms. The water current can be used to turn turbines for hydroelectric generation.
The ocean is an example of a natural resource. Ocean waves can be used to generate wave power, a renewable energy source. Ocean water is important for salt production, desalination, and providing habitat for deep-water fishes. There is biodiversity of marine species in the sea where nutrient cycles are common.
A picture of the Udachnaya pipe, an open-pit diamond mine in Siberia. An example of a non-renewable natural resource.

Natural resources are resources that exist without any actions of humankind. This includes the sources of valued characteristics such as commercial and industrial use, aesthetic value, scientific interest and cultural value. On Earth, it includes sunlight, atmosphere, water, land, all minerals along with all vegetation, and animal life.[1][failed verification][2][3][4] Natural resources can be part of our natural heritage or protected in nature reserves.

Particular areas (such as the rainforest in Fatu-Hiva) often feature biodiversity and geodiversity in their ecosystems. Natural resources may be classified in different ways. Natural resources are materials and components (something that can be used) that can be found within the environment. Every man-made product is composed of natural resources (at its fundamental level). A natural resource may exist as a separate entity such as fresh water, air, as well as any living organism such as a fish, or it may exist in an alternate form that must be processed to obtain the resource such as metal ores, rare-earth elements, petroleum, and most forms of energy.

There is much debate worldwide over natural-resource allocations. This is particularly true during periods of increasing scarcity and shortages (depletion and overconsumption of resources).

Classification

There are various methods of categorizing natural resources. These include the source of origin, stage of development, and by their renewability.

On the basis of origin, natural resources may be divided into two types:

Considering their stage of development, natural resources may be referred to in the following ways:

  • Potential resources — Potential resources are those that may be used in the future—for example, petroleum in sedimentary rocks that, until drilled out and put to use remains a potential resource
  • Actual resources — Those resources that have been surveyed, quantified and qualified, and are currently used in development, such as wood processing, and are typically dependent on technology
  • Reserve resources — The part of an actual resource that can be developed profitably in the future
  • Stock resources — Those that have been surveyed, but cannot be used due to lack of technology—for example, hydrogen

On the basis of recovery rate, natural resources can be categorized as follows:

  • Renewable resources — Renewable resources can be replenished naturally. Some of these resources, like sunlight, air, wind, water, etc. are continuously available and their quantities are not noticeably affected by human consumption. Though many renewable resources do not have such a rapid recovery rate, these resources are susceptible to depletion by over-use. Resources from a human use perspective are classified as renewable so long as the rate of replenishment/recovery exceeds that of the rate of consumption. They replenish easily compared to non-renewable resources.
  • Non-renewable resources – Non-renewable resources either form slowly or do not naturally form in the environment. Minerals are the most common resource included in this category. From the human perspective, resources are non-renewable when their rate of consumption exceeds the rate of replenishment/recovery; a good example of this are fossil fuels, which are in this category because their rate of formation is extremely slow (potentially millions of years), meaning they are considered non-renewable. Some resources naturally deplete in amount without human interference, the most notable of these being radio-active elements such as uranium, which naturally decay into heavy metals. Of these, the metallic minerals can be re-used by recycling them,[5] but coal and petroleum cannot be recycled.[6] Once they are completely used they take millions of years to replenish.

Extraction

Resource extraction involves any activity that withdraws resources from nature. This can range in scale from the traditional use of preindustrial societies to global industry. Extractive industries are, along with agriculture, the basis of the primary sector of the economy. Extraction produces raw material, which is then processed to add value. Examples of extractive industries are hunting, trapping, mining, oil and gas drilling, and forestry. Natural resources can add substantial amounts to a country's wealth; however, a sudden inflow of money caused by a resource boom can create social problems including inflation harming other industries ("Dutch disease") and corruption, leading to inequality and underdevelopment, this is known as the "resource curse".

Extractive industries represent a large growing activity in many less-developed countries but the wealth generated does not always lead to sustainable and inclusive growth. People often accuse extractive industry businesses as acting only to maximize short-term value, implying that less-developed countries are vulnerable to powerful corporations. Alternatively, host governments are often assumed to be only maximizing immediate revenue. Researchers argue there are areas of common interest where development goals and business cross. These present opportunities for international governmental agencies to engage with the private sector and host governments through revenue management and expenditure accountability, infrastructure development, employment creation, skills and enterprise development, and impacts on children, especially girls and women. A strong civil society can play an important role in ensuring the effective management of natural resources. Norway can serve as a role model in this regard as it has good institutions and open and dynamic public debate with strong civil society actors that provide an effective checks and balances system for the government's management of extractive industries, such as the Extractive Industries Transparency Initiative (EITI), a global standard for the good governance of oil, gas and mineral resources. It seeks to address the key governance issues in the extractive sectors.

Depletion of resources

Wind is a natural resource that can be used to generate electricity, as with these 5 MW wind turbines in Thorntonbank Wind Farm 28 km (17 mi) off the coast of Belgium.

In recent years, the depletion of natural resources has become a major focus of governments and organizations such as the United Nations (UN). This is evident in the UN's Agenda 21 Section Two, which outlines the necessary steps for countries to take to sustain their natural resources. The depletion of natural resources is considered a sustainable development issue. The term sustainable development has many interpretations, most notably the Brundtland Commission's 'to ensure that it meets the needs of the present without compromising the ability of future generations to meet their own needs'; however, in broad terms it is balancing the needs of the planet's people and species now and in the future. In regards to natural resources, depletion is of concern for sustainable development as it has the ability to degrade current environments and the potential to impact the needs of future generations.

"The conservation of natural resources is the fundamental problem. Unless we solve that problem, it will avail us little to solve all others."

Theodore Roosevelt

Depletion of natural resources is associated with social inequity. Considering most biodiversity are located in developing countries, depletion of this resource could result in losses of ecosystem services for these countries. Some view this depletion as a major source of social unrest and conflicts in developing nations.

At present, there is a particular concern for rainforest regions that hold most of the Earth's biodiversity. According to Nelson, deforestation and degradation affect 8.5% of the world's forests with 30% of the Earth's surface already cropped. If we consider that 80% of people rely on medicines obtained from plants and 34 of the world's prescription medicines have ingredients taken from plants, loss of the world's rainforests could result in a loss of finding more potential life-saving medicines.

The depletion of natural resources is caused by 'direct drivers of change' such as Mining, petroleum extraction, fishing, and forestry as well as 'indirect drivers of change' such as demography (e.g. population growth), economy, society, politics, and technology. The current practice of Agriculture is another factor causing depletion of natural resources. For example, the depletion of nutrients in the soil due to excessive use of nitrogen and desertification. The depletion of natural resources is a continuing concern for society. This is seen in the cited quote given by Theodore Roosevelt, a well-known conservationist and former United States president, who was opposed to unregulated natural resource extraction.

Protection

In 1982, the United Nations developed the World Charter for Nature, which recognized the need to protect nature from further depletion due to human activity. It states that measures must be taken at all societal levels, from international to individual, to protect nature. It outlines the need for sustainable use of natural resources and suggests that the protection of resources should be incorporated into national and international systems of law. To look at the importance of protecting natural resources further, the World Ethic of Sustainability, developed by the IUCN, WWF and the UNEP in 1990, set out eight values for sustainability, including the need to protect natural resources from depletion. Since the development of these documents, many measures have been taken to protect natural resources including establishment of the scientific field and practice of conservation biology and habitat conservation, respectively.

Conservation biology is the scientific study of the nature and status of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction. It is an interdisciplinary subject drawing on science, economics and the practice of natural resource management. The term conservation biology was introduced as the title of a conference held at the University of California, San Diego, in La Jolla, California, in 1978, organized by biologists Bruce A. Wilcox and Michael E. Soulé.

Habitat conservation is a land management practice that seeks to conserve, protect and restore habitat areas for wild plants and animals, especially conservation reliant species, and prevent their extinction, fragmentation or reduction in range.

Management

Natural resource management is a discipline in the management of natural resources such as land, water, soil, plants, and animals—with a particular focus on how management affects quality of life for present and future generations. Hence, sustainable development is followed according to judicial use of resources to supply both the present generation and future generations. The disciplines of fisheries, forestry, and wildlife are examples of large subdisciplines of natural resource management.

Management of natural resources involves identifying who has the right to use the resources, and who does not, for defining the boundaries of the resource. The resources may be managed by the users according to the rules governing when and how the resource is used depending on local condition or the resources may be managed by a governmental organization or other central authority.

A "...successful management of natural resources depends on freedom of speech, a dynamic and wide-ranging public debate through multiple independent media channels and an active civil society engaged in natural resource issues...", because of the nature of the shared resources the individuals who are affected by the rules can participate in setting or changing them. The users have rights to devise their own management institutions and plans under the recognition by the government. The right to resources includes land, water, fisheries and pastoral rights. The users or parties accountable to the users have to actively monitor and ensure the utilisation of the resource compliance with the rules and to impose penalty on those peoples who violate the rules. These conflicts are resolved in a quick and low cost manner by the local institution according to the seriousness and context of the offence. The global science-based platform to discuss natural resources management is the World Resources Forum, based in Switzerland.

Natural resources by country

Value of natural resources by country (in USD trillions), 2021
Country Value
Russia 79
United States 45
Saudi Arabia 34.4
Canada 33.2
Democratic Republic of Congo 24
China 23
Brazil 21.8
Australia 19.9
Venezuela 14.3
India 0.10

 

Resource depletion

From Wikipedia, the free encyclopedia

Tar sands in Alberta, 2008. Oil is one of the most used resources by humans.

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.

Resource depletion is most commonly used in reference to farming, fishing, mining, water usage, and consumption of fossil fuels. Depletion of wildlife populations is called defaunation.

Depletion accounting

In an effort to offset the depletion of resources, theorists have come up with the concept of 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.

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.

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:

  • Aluminium (2057)
  • Coal (2060)
  • Iron (2068)

Such projections may change, as new discoveries are made and typically misinterpret available data on Mineral Resources and Mineral Reserves.

Oil

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

Deforestation is the clearing of forests by cutting or burning of trees and plants in a forested area. As a result of deforestation, 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.

Deforestation is the removal of a forest or stand of trees from land, the wood is harvested as a resource for production of consumer products and firewood for heat. The land then either left to recover and then will be replanted or is converted to non-forest land used as agricultural land or development of urban areas.

Causes

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.

Environmental impact

Because deforestation is so extensive, it has made several significant impacts on the environment, including:

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.

Controlling deforestation

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

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:

  1. Food and habitat
  2. Improving water quality
  3. Commercial fishing
  4. Floodwater reduction
  5. Shoreline stabilization
  6. Recreation

Resource in wetland

Some of the world's most successful agricultural areas are wetlands that have been drained and 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 hydropower 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.

Bramiana Wetlands

Non-natural causes of wetland degradation

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.

Groundwater

Groundwater flow paths vary greatly in length, depth and travel time from points of recharge to points of discharge in the groundwater system

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.

Environmental impacts

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.

Mitigation

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.

Delayed-choice quantum eraser

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Delayed-choice_quantum_eraser A delayed-cho...