Economics is the study of how humans produce, distribute and consume goods and services, both individually and collectively. As a social science, it looks at the choices made by people, firms, communities and governments.

Scarcity, supply and demand

Natural, human and financial resources are limited, while human wants compete for them. Economics asks three questions: what should be produced, how should it be produced and who should receive it?

Supply is the quantity of a good or service that producers are willing and able to provide. Demand is the quantity that consumers are willing and able to obtain. Buyers and sellers exchange goods or services in a market. Their interaction affects prices, production and consumption.

The outcome of a market isn’t necessarily environmentally desirable. A transaction can benefit the buyer and seller but pass environmental costs on to other people or future generations. Environmental economics begins with this limitation.

Environmental economics is economics applied to the environment and environmental issues. It applies economic reasoning within the existing economy: valuing natural resources and ecosystem services, analysing environmental costs and benefits, and designing policies that change market behaviour.

Perspectives shape the preferred approach

A technocentric perspective is an environmental worldview that places strong confidence in science, technology, management and human innovation. Technocentrics may support cleaner technology, pollution taxes or tradeable permits. These approaches tackle environmental problems while keeping the current economic framework in place.

An ecocentric perspective is an environmental worldview that gives ecosystems and nature-centred values priority in decision-making. Ecocentrics are more likely to favour ecological economics, which asks whether an economy built on continuing material growth can stay within ecological limits.

The disagreement goes beyond choosing a particular tax or technology. At issue is whether the existing economic framework can be corrected, or whether the economy itself must be reorganized as part of the biosphere. Environmental economics can promote sustainability by making environmental costs visible. Its success, though, depends on which values are counted and how strongly policy changes behaviour.

Market failure occurs when the allocation of goods and services by the free market imposes negative impacts on the environment. Here, the market price fails to reflect the full cost to society.

A negative externality is an uncompensated cost or harm from an economic activity that affects people or environments outside the transaction. For example, a manufacturer may release contaminated wastewater without paying for the damage to ecosystems or the cost of downstream water treatment. The firm’s private production costs are therefore lower than the total social and environmental costs. As a result, the product may be underpriced and overproduced.

This pollution causes a net welfare loss. The producer and consumers may benefit, while wider society bears costs despite neither choosing the activity nor receiving compensation. An outcome that appears efficient in the market can therefore remain environmentally and socially inefficient.

When markets fail to prevent environmental harm, policy can shift the cost from society to the responsible party. The polluter-pays principle means that the costs of stopping, managing and cleaning up the pollution are covered by the polluter. The negative externality then becomes part of the polluter's decision-making and production costs.

Environmental economics applies this principle through:

• quotas, which set the maximum permitted level of extraction, production or pollution;
• fines, which punish breaches of environmental rules;
• environmental taxes, which impose a charge on environmentally damaging activities;
• tradeable permits, which create limited rights to emit or use a resource and allow these rights to be exchanged; and
• carbon-neutral certification, which requires measured emissions to be reduced or balanced according to an accepted standard.

A well-designed instrument encourages polluters to prevent damage when prevention costs less than paying the charge or restoring the environment. However, it will only work if there is effective monitoring and enforcement, and if the charge is high enough to change behaviour. When a fine costs less than compliance, a business may simply treat it as another expense.

“Greenwashing” or “green sheen” is where companies use marketing to give themselves a more environmentally friendly image. Greenwashing is a form of misinformation when companies or organizations spend time and money on marketing themselves as sustainable or environmentally friendly rather than on changing practices to become sustainable. The key distinction lies between promoting an image and making substantial change that can be verified.

Greenwashing can take several forms. A company might use vague claims such as “natural”, highlight one minor improvement while ignoring the rest of its impact, or rely on attractive nature imagery. It may also use unsupported carbon-neutral labels or make distant promises without a clear implementation plan. For example, a fossil-fuel producer could advertise a small investment in renewable energy even though its main operations and capital spending remain centred on fossil fuels.

To assess these claims, compare them with evidence from the organization's whole operation. This includes absolute emissions, resource use, waste, supply chains, investment and progress against measurable targets. Independent standards and transparent environmental, social and governance reporting can strengthen accountability. A certification logo, though, is useful only if its criteria and verification are credible.

The tragedy of the commons occurs when property rights are not clearly delineated and a common good has no market price, leading to overexploitation. A common good is a shared resource that is difficult to exclude users from and can be depleted through use, leaving less for others.

An individual user gets the private benefit from extra exploitation, but the environmental cost falls across the whole group. A fisher, grazer or water user may gain by taking more. If everyone behaves in the same way, however, the shared resource deteriorates. This reveals a weakness of an unregulated free market: neither ownership nor price reliably protects the common good.

This outcome isn’t inevitable. Elinor Ostrom's work on shared Swiss pastures showed how local users can build effective institutions. Farmers limited the livestock allowed onto communal summer pasture according to the number each farmer could support on privately held land during winter. These locally agreed limits linked access to responsibility and prevented unrestricted grazing.

Successful community management can use clearly identified users, agreed extraction rules and monitoring, with graduated sanctions and practical methods for resolving disputes. Government regulation, quotas or defined access rights may work too. Coordinated governance changes the incentives, so it is inaccurate to assume that every shared resource must be privatized or will inevitably collapse.

Environmental accounting is the attempt to attach economic value to natural resources and their depletion. It is sometimes called green accounting. Its aim is to record environmental assets and losses that conventional financial or national accounts may miss.

Resource extraction, for instance, may raise conventional economic output even though the loss of forests, soils, minerals or ecosystem functions isn’t recorded. Environmental accounting tries to include both the environment’s economic contribution and the effects of economic activity in the same accounting framework. One international framework used to organize this economic and environmental information is the System of Environmental-Economic Accounting.

Why valuation is contested

Reaching a value that all stakeholders accept is difficult. Estimates vary according to the services included, the time period chosen and whose preferences are counted. The same ecosystem may be valued differently by local residents, businesses, governments, Indigenous communities and future generations. Ethical, spiritual or intrinsic values can also be difficult to express in monetary terms.

Putting a monetary value on environmental depletion can make it harder for decision-makers to ignore. However, that estimate does not represent the ecosystem’s complete value. Valuation is a decision-making tool; it doesn’t prove that every part of nature is replaceable or legitimately available for sale.

Sometimes economic value can be measured through use. That approach doesn’t work for non-use values. A use value is an economic value that can be established through present use of a natural resource or ecosystem service. Use may be direct, as with harvesting food, or indirect, through services such as water purification or flood regulation.

A non-use value is a value attached to an environmental asset independently of its present use. This can include the intrinsic value of a species, possible future use or value for forthcoming generations. Intrinsic value is value possessed by an entity in its own right rather than because it is useful to humans. Future-use value keeps open the possibility of benefit later, while intergenerational value considers people who don’t yet participate in today’s market.

Economists may use surveys because non-use values have no observable market prices. Willingness to pay is the maximum amount a respondent says they would pay to protect a common good. Willingness to accept is the minimum compensation a respondent says they would require for its destruction or loss. After a major marine oil spill, for example, surveys could estimate how much people value protection or restoration—even if they never visit the affected coast.

Question wording can affect these estimates, as can respondents’ income, information and cultural values. A low stated willingness to pay may reflect a limited ability to pay rather than a lack of concern. This makes consensus values difficult to establish.

Ecological economics is different from environmental economics in that it views the economy as a subsystem of Earth's larger biosphere and the social system as being a sub-component of ecology. The economy relies on ecological processes, so it cannot be treated as a closed system separate from nature.

Solar-energy inputs enter the biosphere and sustain its natural processes and resources. Energy and materials then pass into the economic subsystem, where people transform, distribute and consume them. Wastes return to the biosphere, while low-grade thermal energy is ultimately dissipated. Recycling reduces new extraction and waste, but it cannot eliminate material and energy throughput.

Ecological economics therefore stresses the sustainable use of natural capital, the stocks of natural resources and ecosystems that provide useful flows and services. It values this alongside physical capital, such as machinery and infrastructure; human capital, including knowledge and skills; and financial capital.

Another feature is the precautionary principle, an approach under which plausible threats of serious environmental or social harm justify preventive action even when scientific knowledge is incomplete. Complex ecological damage may be uncertain, cumulative or irreversible, which makes this principle relevant.

Environmental economics commonly tries to correct environmental problems within the current market framework. Ecological economics begins with the biosphere's limits, then asks how the economy should be organized within them. This difference helps explain why technocentric perspectives often favour environmental economics, while more ecocentric perspectives tend to support ecological economics.

Environmental economics values the services that ecosystems provide; ecological economics gives this valuation even more weight. An ecosystem service is a benefit that humans obtain from ecosystem structures and processes.

Take a forest. Timber gives it extractive value, but its significance goes much further. The forest may store carbon and regulate water. It can also protect soil, provide habitat, support tourism and recreation, and carry aesthetic or ethical value. Ecological economics puts these wider contributions at the centre instead of treating them as side effects of timber production.

One policy option is for countries that have already depleted substantial natural assets to pay resource-rich developing countries to conserve theirs. These transfers can ease the pressure to clear forests or exhaust other resources for short-term economic development.

This approach can create tensions. Having benefited from its own past depletion, the paying country may seem to be limiting another country's development. Disputes may focus on the size of payments, control of land, the permanence of conservation, distribution of funds and the rights of local or Indigenous communities. For such arrangements to work, they require equitable participation and transparent monitoring. They must also recognise that conservation carries opportunity costs for the resource-rich country.

Economic growth is the change in the total market value of goods and services in a country over a period and is usually measured as the annual percentage change in GDP. A positive annual change shows growth, while a negative change shows economic contraction.

GDP is the monetary measure of all goods and services produced by a country in a given period of time. It is widely used because it combines market output into a single, internationally recognized measure.

Per capita GDP is a country's GDP divided by its total population. When comparing average material living standards, it is generally more useful than total GDP because it accounts for population size.

Neither indicator shows how income is distributed. Per capita GDP may be high even when a small proportion of the population receives much of the country’s income. GDP measures market activity, not overall well-being. It doesn’t directly show health, security, unpaid work, ecosystem condition or whether current production is depleting natural capital. GDP should therefore be treated as an indicator of economic output rather than a complete measure of prosperity or sustainability.

Supply and demand influence economic growth, which may be seen as a measure of prosperity. When demand rises, firms may increase production, investment and employment. Changes in supply affect availability, costs and market prices. Together, these interactions can raise the market value of output recorded in GDP.

The conventional growth model often resembles a linear economy. In this economic system, resources are extracted, made into products, consumed and then discarded. The headline value of production may rise while finite resources are depleted and waste builds up.

This approach usually fails to account fully for waste, pollution and the processes that cause environmental degradation. Spending on pollution clean-up may add to GDP, even though the pollution itself represents a loss of environmental welfare. Measuring prosperity through market growth alone can therefore hide declining natural capital and shift costs to communities, other countries or future generations.

Economic growth can affect environmental welfare in both negative and positive ways.

As incomes and production rise, consumption of non-renewable resources may increase, along with pollution, greenhouse-gas emissions and habitat conversion. Short-term economic interests may drive rapid extraction and consumption, while the ecological damage appears later or somewhere else. As a result, growth can enlarge a country's ecological footprint.

Yet wealthier economies may have more public revenue, investment capacity and scientific expertise to put into renewable energy, protected areas, pollution control, public transport and ecosystem restoration. These benefits aren't automatic. They depend on political priorities, regulation and the distribution of resources.

Environmental justice

Environmental justice is the principle that environmental benefits, burdens and decision-making power should be distributed fairly. Affluent consumers may benefit from increased consumption, while low-income groups, marginalized communities, resource-exporting regions or future generations bear a disproportionate share of pollution, resource loss or climate impacts.

GDP alone can't show how growth affects sustainability. A balanced judgement considers what is growing, the resources and technologies that support it, who gains, who bears the damage and whether environmental pressures fall in absolute terms.

Eco-economic decoupling is the notion of separating economic growth from environmental degradation. Its goal is to improve economic value and human well-being without a corresponding rise in resource extraction, pollution, waste or greenhouse-gas emissions.

Renewable energy, lower-carbon production and resource-efficient design can all help achieve decoupling. So can repair, reuse, recycling and waste prevention. Together, these approaches move production away from the take–make–dispose model of a linear economy and towards a circular economy—an economic system designed to keep products and materials in use while reducing virgin-resource inputs and waste outputs.

Any convincing claim of decoupling needs to consider the entire supply chain. A country might report lower domestic emissions while importing pollution-intensive products, which simply shifts the ecological costs to another region. Efficiency gains may also be cancelled out when total consumption grows faster than the environmental impact per unit declines.

To support the sustainability of Earth's systems, reductions must be substantial, sustained and global—not just local accounting changes. Economics can contribute to sustainability only when economic decisions account for environmental limits and social consequences instead of leaving them outside the market.