Nanowire battery

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https://en.wikipedia.org/wiki/Nanowire_battery 

A nanowire battery uses nanowires to increase the surface area of one or both of its electrodes. Some designs (silicon, germanium and transition metal oxides), variations of the lithium-ion battery have been announced, although none are commercially available. All of the concepts replace the traditional graphite anode and could improve battery performance.

Silicon

Silicon is an attractive material for applications as lithium battery anodes because it offers advantageous material properties. In particular, silicon has a low discharge potential and a high theoretical charge capacity ten times higher than that of typical graphite anodes currently used in industry. Nanowires could improve these properties by increasing the amount of available surface area in contact with the electrolyte, thereby increasing the anode’s power density and allowing for faster charging and higher current delivery. However, the use of silicon anodes in batteries has been limited by the volume expansion during lithiation. Silicon swells by 400% as it intercalates lithium during charging, resulting in degradation of the material. This volume expansion occurs anisotropically, caused by crack propagation immediately following a moving lithiation front. These cracks result in pulverization and substantial capacity loss noticeable within the first few cycles.

The extensive 2007 Review Article by Kasavajjula et al. summarizes early research on silicon-based anodes for lithium-ion secondary cells. In particular, Hong Li et al showed in 2000 that the electrochemical insertion of lithium ions in silicon nanoparticles and silicon nanowires leads to the formation of an amorphous Li-Si alloy. The same year, Bo Gao and his doctoral advisor, Professor Otto Zhou described the cycling of electrochemical cells with anodes comprising silicon nanowires, with a reversible capacity ranging from at least approximately 900 to 1500 mAh/g.

Research done at Stanford University indicates that silicon nanowires (SiNWs) grown directly on the current collector (via VLS growth methods) are able to circumvent the negative effects associated with volume expansion. This geometry lends itself to several advantages. First, the nanowire diameter allows for improved accommodation of volume changes during lithiation without fracture. Second, each nanowire is attached to the current collector such that each can contribute to the overall capacity. Third, the nanowires are direct pathways for charge transport; in particle-based electrodes, charges are forced to navigate interparticle contact areas (a less efficient process). Silicon nanowires have a theoretical capacity of roughly 4,200 mAh g^-1, which is larger than the capacity of other forms of silicon. This value indicates a significant improvement over graphite, which has a theoretical capacity of 372 mAh g^-1 in its fully lithiated state of LiC₆.

Additional research has involved depositing carbon coatings onto silicon nanowires, which helps stabilize the material such that a stable solid electrolyte interphase (SEI) forms. An SEI is an inevitable byproduct of the electrochemistry that occurs in the battery; its formation contributes to decreased capacity in the battery since it is an electrically insulating phase (despite being ionically conductive). It can also dissolve and reform over multiple battery cycles. Hence, a stable SEI is preferable in order to prevent continued capacity loss as the battery is used. When carbon is coated onto silicon nanowires, capacity retention has been observed at 89% of the initial capacity after 200 cycles. This capacity retention is on par with that of graphitic anodes today.

One design uses a stainless steel anode covered in silicon nanowires. Silicon stores ten times more lithium than graphite, offering increased energy density. The large surface area increases the anode's power density, thereby allowing for fast charging and high current delivery. The anode was invented at Stanford University in 2007.

In September 2010, researchers demonstrated 250 charge cycles maintaining above 80 percent of initial storage capacity. However, some studies pointed out that Si nanowire anodes exhibit significant fade in energy capacity with more charge cycles; this is caused by the volumetric expansion of silicon nanowires during lithiation process. Researchers has proposed many solutions to remedy this problem: published results in 2012 showed that doping impurities to the nanowire anode improves the battery performance, and it was found that phosphorus-doped Si nanowires achieved better performance when compared with boron and undoped nanowire electrodes; researchers also demonstrated the possibility of sustaining an 85% of initial capacity after cycling over 6,000 times by placing a nominally undoped silicon anode into a doubled-walled silicon nanotube with silicon oxide ion-permeating layer as coating.

The silicon nanowire-based battery cell also provides opportunity for dimensional flexible energy source, which would also leads to the development of wearable technological device. Scientist from Rice University showed this possibility by depositing porous copper nanoshells around the silicon nanowire within a polymer matrix. This lithium-polymer silicon nanowire battery (LIOPSIL) has a sufficient operational full cell voltage of 3.4V and is mechanically flexible and scalable.

Commercialization was originally expected to occur in 2012, but was later deferred to 2014. A related company, Amprius, shipped a related device with silicon and other materials in 2013. Canonical announced on July 22, 2013, that its Ubuntu Edge smartphone would contain a silicon-anode lithium-ion battery.

Germanium

An anode using germanium nanowire was claimed to have the ability to increase the energy density and cycle durability of lithium-ion batteries. Like silicon, germanium has a high theoretical capacity (1600 mAh g-1), expands during charging, and disintegrates after a small number of cycles. However, germanium is 400 times more effective at intercalating lithium than silicon, making it an attractive anode material. The anodes claimed to retain capacities of 900 mAh/g after 1100 cycles, even at discharge rates of 20–100C. This performance was attributed to a restructuring of the nanowires that occurs within the first 100 cycles to form a mechanically robust, continuously porous network. Once formed, the restructured anode loses only 0.01% of capacity per cycle thereafter. The material forms a stable structure after these initial cycles that is capable of withstanding pulverization. In 2014, researchers developed a simple way to produce nanowires of germanium from an aqueous solution.

Transition metal oxides

Transition metal oxides (TMO), such as Cr₂O₃, Fe₂O₃, MnO₂, Co₃O₄ and PbO₂, have many advantages as anode materials over conventional cell materials for lithium-ion battery (LIB) and other battery systems. Some of them possess high theoretical energy capacity, and are naturally abundant, non-toxic and also environmental friendly. As the concept of the nanostructred battery electrode has been introduced, experimentalists start to look into the possibility of TMO-based nanowires as electrode materials. Some recent investigations into this concept are discussed in the following subsection.

Lead oxide anode

Lead-acid battery is the oldest type of rechargeable battery cell. Even though the raw material (PbO₂) for the cell production is fairly accessible and cheap, lead-acid battery cells have relatively small specific energy. The paste thickening effect (volumetric expansion effect) during the operation cycle also blocks the effective flow of the electrolyte. These problems limited the potential of the cell to accomplish some energy-intensive tasks.

In 2014, experimentalist successfully obtained PbO₂ nanowire through simple template electrodeposition. The performance of this nanowire as anode for lead-acid battery has also been evaluated. Due to largely increased surface area, this cell was able to deliver an almost constant capacity of about 190 mAh g⁻¹ even after 1,000 cycles. This result showed this nanostructured PbO₂ as a fairly promising substitute for the normal lead-acid anode.

Manganese oxide

MnO₂ has always been a good candidate for electrode materials due to its high energy capacity, non-toxicity and cost effectiveness. However, lithium-ion insertion into the crystal matrix during charging/discharging cycle would cause significant volumetric expansion. To counteract this effect during operation cycle, scientists recently proposed the idea of producing a Li-enriched MnO₂ nanowire with a nominal stoichiometry of Li₂MnO₃ as anode materials for LIB. This new proposed anode materials enable the battery cell to reach an energy capacity of 1279 mAh g⁻¹ at current density of 500 mA even after 500 cycles. This performance is much higher than that of pure MnO₂ anode or MnO₂ nanowire anode cells.

Heterostructure TMOs

Heterojunction of different transition metal oxides would sometimes provide the potential of a more well-rounded performance of LIBs.

In 2013, researchers successfully synthesized a branched Co₃O₄/Fe₂O₃ nanowire heterostructure using hydrothermal method. This heterojunction can be used as an alternative anode for the LIB cell. At operation, Co₃O₄ promotes a more efficient ionic transport, while Fe₂O₃ enhances the theoretical capacity of the cell by increasing the surface area. A high reversible capacity of 980 mAh g⁻¹ was reported.

The possibility of fabrication heterogeneous ZnCo₂O₄/NiO nanowire arrays anode has also been explored in some studies. However, the efficiency of this material as anode is still to be evaluated.

Gold

In 2016, researchers at the University of California, Irvine announced the invention of a nanowire material capable of over 200,000 charge cycles without any breakage of the nanowires. The technology could lead to batteries that never need to be replaced in most applications. The gold nanowires are strengthened by a manganese dioxide shell encased in an Plexiglas-like gel electrolyte. The combination is reliable and resistant to failure. After cycling a test electrode about 200,000 times, no loss of capacity or power, nor fracturing of any nanowires occurred.

Algebraic structure

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Algebraic_structure 

In mathematics, an algebraic structure consists of a nonempty set A (called the underlying set, carrier set or domain), a collection of operations on A (typically binary operations such as addition and multiplication), and a finite set of identities, known as axioms, that these operations must satisfy.

An algebraic structure may be based on other algebraic structures with operations and axioms involving several structures. For instance, a vector space involves a second structure called a field, and an operation called scalar multiplication between elements of the field (called scalars), and elements of the vector space (called vectors).

Abstract algebra is the name that is commonly given to the study of algebraic structures. The general theory of algebraic structures has been formalized in universal algebra. Category theory is another formalization that includes also other mathematical structures and functions between structures of the same type (homomorphisms).

In universal algebra, an algebraic structure is called an algebra; this term may be ambiguous, since, in other contexts, an algebra is an algebraic structure that is a vector space over a field or a module over a commutative ring.

The collection of all structures of a given type (same operations and same laws) is called a variety in universal algebra; this term is also used with a completely different meaning in algebraic geometry, as an abbreviation of algebraic variety. In category theory, the collection of all structures of a given type and homomorphisms between them form a concrete category.

Introduction

Addition and multiplication are prototypical examples of operations that combine two elements of a set to produce a third element of the same set. These operations obey several algebraic laws. For example, a + (b + c) = (a + b) + c and a(bc) = (ab)c are associative laws, and a + b = b + a and ab = ba are commutative laws. Many systems studied by mathematicians have operations that obey some, but not necessarily all, of the laws of ordinary arithmetic. For example, the possible moves of an object in three-dimensional space can be combined by performing a first move of the object, and then a second move from its new position. Such moves, formally called rigid motions, obey the associative law, but fail to satisfy the commutative law.

Sets with one or more operations that obey specific laws are called algebraic structures. When a new problem involves the same laws as such an algebraic structure, all the results that have been proved using only the laws of the structure can be directly applied to the new problem.

In full generality, algebraic structures may involve an arbitrary collection of operations, including operations that combine more than two elements (higher arity operations) and operations that take only one argument (unary operations) or even zero arguments (nullary operations). The examples listed below are by no means a complete list, but include the most common structures taught in undergraduate courses.

Common axioms

Equational axioms

An axiom of an algebraic structure often has the form of an identity, that is, an equation such that the two sides of the equals sign are expressions that involve operations of the algebraic structure and variables. If the variables in the identity are replaced by arbitrary elements of the algebraic structure, the equality must remain true. Here are some common examples.

Commutativity

An operation ${\displaystyle \ast }$ is commutative if

$${\displaystyle x\ast y=y\ast x}$$

for every x and y in the algebraic structure.

Associativity

An operation ${\displaystyle \ast }$ is associative if

$${\displaystyle (x\ast y)\ast z=x\ast (y\ast z)}$$

for every x, y and z in the algebraic structure.

Left distributivity

An operation ${\displaystyle \ast }$ is left distributive with respect to another operation ${\displaystyle +}$ if

$${\displaystyle x\ast (y+z)=(x\ast y)+(x\ast z)}$$

for every x, y and z in the algebraic structure (the second operation is denoted here as +, because the second operation is addition in many common examples).

Right distributivity

An operation ${\displaystyle \ast }$ is right distributive with respect to another operation ${\displaystyle +}$ if

$${\displaystyle (y+z)\ast x=(y\ast x)+(z\ast x)}$$

for every x, y and z in the algebraic structure.

Distributivity

An operation ${\displaystyle \ast }$ is distributive with respect to another operation ${\displaystyle +}$ if it is both left distributive and right distributive. If the operation ${\displaystyle \ast }$ is commutative, left and right distributivity are both equivalent to distributivity.

Existential axioms

Some common axioms contain an existential clause. In general, such a clause can be avoided by introducing further operations, and replacing the existential clause by an identity involving the new operation. More precisely, let us consider an axiom of the form "for all X there is y such that ${\displaystyle f(X,y)=g(X,y)}$", where X is a k-tuple of variables. Choosing a specific value of y for each value of X defines a function ${\displaystyle \phi :X\mapsto y,}$ which can be viewed as an operation of arity k, and the axiom becomes the identity ${\displaystyle f(X,\phi (X))=g(X,\phi (X)).}$

The introduction of such auxiliary operation complicates slightly the statement of an axiom, but has some advantages. Given a specific algebraic structure, the proof that an existential axiom is satisfied consists generally of the definition of the auxiliary function, completed with straightforward verifications. Also, when computing in an algebraic structure, one generally uses explicitly the auxiliary operations. For example, in the case of numbers, the additive inverse is provided by the unary minus operation ${\displaystyle x\mapsto -x.}$

Also, in universal algebra, a variety is a class of algebraic structures that share the same operations, and the same axioms, with the condition that all axioms are identities. What precedes shows that existential axioms of the above form are accepted in the definition of a variety.

Here are some of the most common existential axioms.

Identity element

A binary operation ${\displaystyle \ast }$ has an identity element if there is an element e such that

$${\displaystyle x\ast e=x\text{and}e\ast x=x}$$

for all x in the structure. Here, the auxiliary operation is the operation of arity zero that has e as its result.

Inverse element

Given a binary operation ${\displaystyle \ast }$ that has an identity element e, an element x is invertible if it has an inverse element, that is, if there exists an element ${\displaystyle \mathrm{inv}(x)}$ such that

$${\displaystyle \mathrm{inv}(x)\ast x=e\text{and}x\ast \mathrm{inv}(x)=e.}$$

For example, a group is an algebraic structure with a binary operation that is associative, has an identity element, and for which all elements are invertible.

Non-equational axioms

The axioms of an algebraic structure can be any first-order formula, that is a formula involving logical connectives (such as "and", "or" and "not"), and logical quantifiers (${\displaystyle \mathrm{\forall },\mathrm{\exists }}$) that apply to elements (not to subsets) of the structure.

Such a typical axiom is inversion in fields. This axiom cannot be reduced to axioms of preceding types. (it follows that fields do not form a variety in the sense of universal algebra.) It can be stated: "Every nonzero element of a field is invertible;" or, equivalently: the structure has a unary operation inv such that

${\displaystyle \mathrm{\forall }x,x=0\text{or}x\cdot \mathrm{inv}(x)=1.}$

The operation inv can be viewed either as a partial operation that is not defined for x = 0; or as an ordinary function whose value at 0 is arbitrary and must not be used.

Common algebraic structures

Main article: Outline of algebraic structures § Types of algebraic structures

One set with operations

Simple structures: no binary operation:

• Set: a degenerate algebraic structure S having no operations.

Group-like structures: one binary operation. The binary operation can be indicated by any symbol, or with no symbol (juxtaposition) as is done for ordinary multiplication of real numbers.

• Group: a monoid with a unary operation (inverse), giving rise to inverse elements.
• Abelian group: a group whose binary operation is commutative.

Ring-like structures or Ringoids: two binary operations, often called addition and multiplication, with multiplication distributing over addition.

• Ring: a semiring whose additive monoid is an abelian group.
• Division ring: a nontrivial ring in which division by nonzero elements is defined.
• Commutative ring: a ring in which the multiplication operation is commutative.
• Field: a commutative division ring (i.e. a commutative ring which contains a multiplicative inverse for every nonzero element).

Lattice structures: two or more binary operations, including operations called meet and join, connected by the absorption law.

• Complete lattice: a lattice in which arbitrary meet and joins exist.
• Bounded lattice: a lattice with a greatest element and least element.
• Distributive lattice: a lattice in which each of meet and join distributes over the other. A power set under union and intersection forms a distributive lattice.
• Boolean algebra: a complemented distributive lattice. Either of meet or join can be defined in terms of the other and complementation.

Two sets with operations

• Module: an abelian group M and a ring R acting as operators on M. The members of R are sometimes called scalars, and the binary operation of scalar multiplication is a function R × M → M, which satisfies several axioms. Counting the ring operations these systems have at least three operations.
• Vector space: a module where the ring R is a division ring or field.

• Algebra over a field: a module over a field, which also carries a multiplication operation that is compatible with the module structure. This includes distributivity over addition and linearity with respect to multiplication.
• Inner product space: an F vector space V with a definite bilinear form V × V → F.

Hybrid structures

Algebraic structures can also coexist with added structure of non-algebraic nature, such as partial order or a topology. The added structure must be compatible, in some sense, with the algebraic structure.

• Topological group: a group with a topology compatible with the group operation.
• Lie group: a topological group with a compatible smooth manifold structure.
• Ordered groups, ordered rings and ordered fields: each type of structure with a compatible partial order.
• Archimedean group: a linearly ordered group for which the Archimedean property holds.
• Topological vector space: a vector space whose M has a compatible topology.
• Normed vector space: a vector space with a compatible norm. If such a space is complete (as a metric space) then it is called a Banach space.
• Hilbert space: an inner product space over the real or complex numbers whose inner product gives rise to a Banach space structure.
• Vertex operator algebra
• Von Neumann algebra: a *-algebra of operators on a Hilbert space equipped with the weak operator topology.

Universal algebra

Main article: Universal algebra

Algebraic structures are defined through different configurations of axioms. Universal algebra abstractly studies such objects. One major dichotomy is between structures that are axiomatized entirely by identities and structures that are not. If all axioms defining a class of algebras are identities, then this class is a variety (not to be confused with algebraic varieties of algebraic geometry).

Identities are equations formulated using only the operations the structure allows, and variables that are tacitly universally quantified over the relevant universe. Identities contain no connectives, existentially quantified variables, or relations of any kind other than the allowed operations. The study of varieties is an important part of universal algebra. An algebraic structure in a variety may be understood as the quotient algebra of term algebra (also called "absolutely free algebra") divided by the equivalence relations generated by a set of identities. So, a collection of functions with given signatures generate a free algebra, the term algebra T. Given a set of equational identities (the axioms), one may consider their symmetric, transitive closure E. The quotient algebra T/E is then the algebraic structure or variety. Thus, for example, groups have a signature containing two operators: the multiplication operator m, taking two arguments, and the inverse operator i, taking one argument, and the identity element e, a constant, which may be considered an operator that takes zero arguments. Given a (countable) set of variables x, y, z, etc. the term algebra is the collection of all possible terms involving m, i, e and the variables; so for example, m(i(x), m(x, m(y,e))) would be an element of the term algebra. One of the axioms defining a group is the identity m(x, i(x)) = e; another is m(x,e) = x. The axioms can be represented as trees. These equations induce equivalence classes on the free algebra; the quotient algebra then has the algebraic structure of a group.

Some structures do not form varieties, because either:

1. It is necessary that 0 ≠ 1, 0 being the additive identity element and 1 being a multiplicative identity element, but this is a nonidentity;
2. Structures such as fields have some axioms that hold only for nonzero members of S. For an algebraic structure to be a variety, its operations must be defined for all members of S; there can be no partial operations.

Structures whose axioms unavoidably include nonidentities are among the most important ones in mathematics, e.g., fields and division rings. Structures with nonidentities present challenges varieties do not. For example, the direct product of two fields is not a field, because ${\displaystyle (1,0)\cdot (0,1)=(0,0)}$, but fields do not have zero divisors.

Category theory

Category theory is another tool for studying algebraic structures (see, for example, Mac Lane 1998). A category is a collection of objects with associated morphisms. Every algebraic structure has its own notion of homomorphism, namely any function compatible with the operation(s) defining the structure. In this way, every algebraic structure gives rise to a category. For example, the category of groups has all groups as objects and all group homomorphisms as morphisms. This concrete category may be seen as a category of sets with added category-theoretic structure. Likewise, the category of topological groups (whose morphisms are the continuous group homomorphisms) is a category of topological spaces with extra structure. A forgetful functor between categories of algebraic structures "forgets" a part of a structure.

There are various concepts in category theory that try to capture the algebraic character of a context, for instance

• algebraic category
• essentially algebraic category
• presentable category
• locally presentable category
• monadic functors and categories
• universal property.

Different meanings of "structure"

In a slight abuse of notation, the word "structure" can also refer to just the operations on a structure, instead of the underlying set itself. For example, the sentence, "We have defined a ring structure on the set ${\displaystyle A}$," means that we have defined ring operations on the set ${\displaystyle A}$. For another example, the group ${\displaystyle (\mathbb{Z},+)}$ can be seen as a set ${\displaystyle \mathbb{Z}}$ that is equipped with an algebraic structure, namely the operation ${\displaystyle +}$.

Overconsumption (economics)

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Overconsumption_(economics)

Overconsumption describes a situation where a consumer overuses their available goods and services to where they can't, or don't want to, replenish or reuse them. In microeconomics, this may be described as the point where the marginal cost of a consumer is greater than their marginal utility. The term overconsumption is quite controversial in use and does not necessarily have a single unifying definition. When used to refer to natural resources to the point where the environment is negatively affected, is it synonymous with the term overexploitation. However, when used in the broader economic sense, overconsumption can refer to all types of goods and services, including manmade ones, e.g. "the overconsumption of alcohol can lead to alcohol poisoning". Overconsumption is driven by several factors of the current global economy, including forces like consumerism, planned obsolescence, economic materialism, and other unsustainable business models and can be contrasted with sustainable consumption.

Defining the amount of a natural resource required to be consumed for it to count as "overconsumption" is challenging because defining a sustainable capacity of the system requires accounting for many variables. The total capacity of a system occurs at both the regional and worldwide levels, which means that certain regions may have higher consumption levels of certain resources than others due to greater resources without overconsuming a resource. A long-term pattern of overconsumption in any given region or ecological system can cause a reduction in natural resources that often results in environmental degradation. However, this is only when applying the word to human impacts on the environment. When used in an economic sense, this point is defined as when the marginal cost of a consumer is equal to their marginal utility. Gossen's law of diminishing utility states that at this point, the consumer realizes the cost of consuming/purchasing another item/good is not worth the amount of utility (a.k.a. happiness or satisfaction from the good) they'd receive, and therefore is not conducive to the consumer's wellbeing.

When used in the environmental sense, the discussion of overconsumption often parallels that of population size and growth, and human development: more people demanding higher qualities of living, currently requires greater extraction of resources, which causes subsequent environmental degradation such as climate change and biodiversity loss. Currently, the inhabitants of high wealth, "developed" nations consume resources at a rate almost 32 times greater than those of the developing world, who make up the majority of the human population (7.9 billion people). However, the developing world is a growing consumer market. These nations are quickly gaining more purchasing power and it is expected that the Global South, which includes cities in Asia, America, and Africa, will account for 56% of consumption growth by 2030.  This means that if current trends continue relative consumption rates will shift more into these developing countries, whereas developed countries would start to plateau. Sustainable Development Goal 12 "responsible consumption and production" is the main international policy tool with goals to abate the impact of overconsumption.

Causes

Economic growth

If everyone consumed resources at the US level, you will need another four or five Earths.

—Paul R. Ehrlich, biologist

Economic growth is sometimes seen as a driver for overconsumption. Economic growth can be seen as a catalyst of overconsumption due to it requiring greater resource input to sustain the growth. China is an example where this phenomenon has been observed readily. China’s GDP increased massively from 1978, and energy consumption has increased by 6-fold. By 1983, China’s consumption surpassed the biocapacity of their natural resources, leading to overconsumption. In the last 30-40 years, China has seen significant increases in its pollution, land degradation, and non-renewable resource depletion, which aligns with its considerable economic growth. It is unknown if other rapidly developing nations will see similar trends in resource overconsumption.

The Worldwatch Institute said China and India, with their booming economies, along with the United States, are the three planetary forces that are shaping the global biosphere. The State of the World 2005 report said the two countries' high economic growth exposed the reality of severe pollution. The report states that

The world's ecological capacity is simply insufficient to satisfy the ambitions of China, India, Japan, Europe, and the United States as well as the aspirations of the rest of the world in a sustainable way.

In 2019, a warning on the climate crisis signed by 11,000 scientists from over 150 nations said economic growth is the driving force behind the "excessive extraction of materials and overexploitation of ecosystems" and that this "must be quickly curtailed to maintain long-term sustainability of the biosphere." Also in 2019, the Global Assessment Report on Biodiversity and Ecosystem Services published by the United Nations' Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, which found that up to one million species of plants and animals are at risk of extinction from human activity, asserted that

A key element of more sustainable future policies is the evolution of global financial and economic systems to build a global sustainable economy, steering away from the current limited paradigm of economic growth.

Consumerism

SUVs are a popular type of vehicle

Consumerism is a social and economic order that encourages the acquisition of goods and services in ever-increasing amounts. There is a spectrum of goods and services that the world population constantly consumes. These range from food and beverage, clothing and footwear, housing, energy, technology, transportation, education, health and personal care, financial services, and other utilities. When the resources required to produce these goods and services are depleted beyond a reasonable level, it can be considered to be overconsumption. Because developing nations are rising quickly into the consumer class, the trends happening in these nations are of special interest. According to the World Bank, the highest shares of consumption, regardless of income lie in food, beverage, clothing, and footwear. As of 2015, the top five consumer markets in the world included the United States, Japan, Germany, China, and France.

Planned and perceived obsolescence is an important factor that explains why some overconsumption of consumer products exists.  This factor of the production revolves around designing products with the intent to be discarded after a short period of time. Perceived obsolescence is prevalent within the fashion and technology industries. Through this technique, products are made obsolete and replaced on a semi-regular basis. Frequent new launches of technology or fashion lines can be seen as a form of marketing-induced perceived obsolescence. Products designed to break after a certain period of time or use would be considered to be planned obsolescence.

Effects

See also: Economic effects of climate change and I PAT

 

Waste generation, measured in kilograms per person per day

A fundamental effect of overconsumption is a reduction in the planet's carrying capacity. Excessive unsustainable consumption will exceed the long-term carrying capacity of its environment (ecological overshoot) and subsequent resource depletion, environmental degradation and reduced ecosystem health. In 2020 multinational team of scientists published a study, saying that overconsumption is the biggest threat to sustainability. According to the study, a drastic lifestyle change is necessary for solving the ecological crisis. According to one of the authors Julia Steinberger: “To protect ourselves from the worsening climate crisis, we must reduce inequality and challenge the notion that riches, and those who possess them, are inherently good.” The research was published on the site of the World Economic Forum. The leader of the forum professor Klaus Schwab, calls to a "great reset of capitalism".

A 2020 study published in Scientific Reports, in which both population growth and deforestation were used as proxies for total resource consumption, warns that if consumption continues at the current rate for the next several decades, it can trigger a full or almost full extinction of humanity. The study says that "while violent events, such as global war or natural catastrophic events, are of immediate concern to everyone, a relatively slow consumption of the planetary resources may be not perceived as strongly as a mortal danger for the human civilization." To avoid it humanity should pass from a civilization dominated by the economy to a "cultural society" that "privileges the interest of the ecosystem above the individual interest of its components, but eventually in accordance with the overall communal interest."

The worldwide prevalence of obesity in males (2008)- the darker areas represent a higher percentage of obese males

The scale of modern life's overconsumption can lead to a decline in economy and an increase in financial instability. Some argue that overconsumption enables the existence of an "overclass", while others disagree with the role of overconsumption in class inequality. Population, Development, and Poverty all coincide with overconsumption; how they interplay with each other is complex. Because of this complexity it is difficult to determine the role of consumption in terms of economic inequality.

Great Pacific garbage patch

In the long term, these effects can lead to increased conflict over dwindling resources and in the worst case a Malthusian catastrophe. Lester Brown of the Earth Policy Institute, has said: "It would take 1.5 Earths to sustain our present level of consumption. Environmentally, the world is in an overshoot mode."

As of 2012, the United States alone was using 30% of the world's resources and if everyone were to consume at that rate, we would need 3-5 planets to sustain this type of living. Resources are quickly becoming depleted, with about ⅓ already gone. With new consumer markets rising in the developing countries which account for a much higher percentage of the world's population, this number can only rise. According to Sierra Club’s Dave Tilford, "With less than 5 percent of world population, the U.S. uses one-third of the world’s paper, a quarter of the world’s oil, 23 percent of the coal, 27 percent of the aluminum, and 19 percent of the copper." According to BBC, a World Bank study has found that "Americans produce 16.5 tonnes of carbon dioxide per capita every year. By comparison, only 0.1 tonnes of the greenhouse gas is generated in Ethiopia per inhabitant."

A 2021 study published in Frontiers in Conservation Science posits that aggregate consumption growth will continue into the near future and perhaps beyond, largely due to increasing affluence and population growth. The authors argue that "there is no way—ethically or otherwise (barring extreme and unprecedented increases in human mortality)—to avoid rising human numbers and the accompanying overconsumption", although they do say that the negative impacts of overconsumption can perhaps be diminished by implementing human rights policies to lower fertility rates and decelerate current consumption patterns.

Effects on health

A report from the Lancet Commission says the same. The experts write: "Until now, undernutrition and obesity have been seen as polar opposites of either too few or too many calories," "In reality, they are both driven by the same unhealthy, inequitable food systems, underpinned by the same political economy that is single-focused on economic growth, and ignores the negative health and equity outcomes. Climate change has the same story of profits and power,". Obesity was a medical problem for people who overconsumed food and worked too little already in ancient Rome, and its impact slowly grew through history. As to 2012, mortality from obesity was 3 times larger than from hunger, reaching 2.8 million people per year by 2017.

Overuse of artificial energy, for example, in cars, hurts health and the planet. Promoting active living and reducing sedentary lifestyle, for example, by cycling, reduces greenhouse gas emissions and improve health

Global estimates

In 2010, the International Resource Panel published the first global scientific assessment on the impacts of consumption and production. The study found that the most critical impacts are related to ecosystem health, human health and resource depletion. From a production perspective, it found that fossil-fuel combustion processes, agriculture and fisheries have the most important impacts. Meanwhile, from a final consumption perspective, it found that household consumption related to mobility, shelter, food, and energy-using products causes the majority of life-cycle impacts of consumption.

According to the IPCC Fifth Assessment Report, human consumption, with current policy, by the year 2100 will be seven times bigger than in the year 2010.

Footprint

Main article: Ecological footprint

See also: Lists of organisms by population

The planet can’t support billions of meat-eaters.

—David Attenborough, natural historian

The idea of overconsumption is also strongly tied to the idea of an ecological footprint. The term "ecological footprint" refers to the "resource accounting framework for measuring human demand on the biosphere." Currently, China, for instance, has a per person ecological footprint roughly half the size of the US, yet has a population that is more than four times the size of the US. It is estimated that if China developed to the level of the United States that world consumption rates would roughly double.

Humans, their prevailing growth of demands for livestock and other domestic animals, has added overshoot through domestic animal breeding, keeping, and consumption, especially with the environmentally destructive industrial livestock production. Globalization and modernization have brought Western consumer cultures to countries like China and India, including meat-intensive diets which are supplanting traditional plant-based diets. Between 166 to more than 200 billion land and aquatic animals are consumed by a global population of over 7 billion annually. A 2018 study published in Science postulates that meat consumption is set to increase as the result of human population growth and rising affluence, which will increase greenhouse gas emissions and further reduce biodiversity. Meat consumption needs to be reduced in order to make agriculture sustainable by up to 90% according to a 2018 study published in Nature.

Ecological footprint for many years has been used by environmentalists as a way to quantify ecological degradation as it relates to an individual. Recently, there has been debate about the reliability of this method. 

Biomass of mammals on Earth

  Livestock, mostly cattle and pigs (60%)

  Humans (36%)

  Wild animals (4%)

Counteractions

The most obvious solution to the issue of overconsumption is to simply slow the rate at which materials are becoming depleted. From a capitalistic point of view, less consumption has negative effects on economies and so instead, countries must look to curb consumption rates but also allow for new industries, such as renewable energy and recycling technologies, to flourish and deflect some of the economic burdens. Some movements think that a reduction in consumption in some cases can benefit the economy and society. They think that a fundamental shift in the global economy may be necessary to account for the current change that is taking place or that will need to take place. Movements and lifestyle choices related to stopping overconsumption include: anti-consumerism, freeganism, green economics, ecological economics, degrowth, frugality, downshifting, simple living, minimalism, the slow movement, and thrifting.

Many consider the final target of the movements as arriving to a steady-state economy in which the rate of consumption is optimal for health and environment.

Recent grassroots movements have been coming up with creative ways to decrease the number of goods we consume. The Freecycle Network is a network of people in one's community that are willing to trade goods for other goods or services. It is a new take on thrifting while still being beneficial to both parties.

Other researchers and movements such as the Zeitgeist Movement suggest a new socioeconomic model which, through a structural increase of efficiency, collaboration and locality in production as well as effective sharing, increased modularity, sustainability and optimal design of products, are expected to reduce resource-consumption. Solutions offered include consumers using market forces to influence businesses towards more sustainable manufacturing and products.

Another way to reduce consumption is to slow population growth by improving family planning services worldwide. In developing countries, more than 200 million women do not have adequate access. Women's empowerment in these countries will also result in smaller families.