Abiotic factors are the non-living physical and chemical elements, such as temperature, sunlight, and soil composition.

Adaptation is the process of adjusting natural or human systems in response to actual or expected climate impacts, reducing harm or exploiting beneficial opportunities.

Adaptation is a heritable trait that increases an organism’s chances of survival and reproduction in a particular environment.

Adhesion is the attraction between unlike substances, often involving polar or charged surfaces.

Advection is the wind-blown transport of water vapour or condensed/frozen droplets from one region to another, helping connect local hydrological cycles globally.

Aeration is the exchange of gases between soil and the atmosphere.

Aerosols are tiny solid or liquid particles suspended in the atmosphere.

Aesthetic value refers to the beauty and visual appeal of natural landscapes, which inspire art, photography, and personal reflection.

An age-sex pyramid visually represents the composition of a population by age groups and gender.

Agricultural system refers to the combination of crops, livestock, technologies, and management methods used by farmers under specific environmental and socio-economic conditions.

Albedo refers to how much solar energy is reflected by the Earth's surface.

Ammonification (a type of decomposition) converts organic nitrogen (e.g., amino acids, urea) into ammonia or ammonium ions.

Anoxia is the complete absence of dissolved oxygen.

Anthropocene means “the age of humans”, emphasizing the unprecedented role humans play in altering Earth’s geology, atmosphere, and biosphere.

Anthropocentrism places human needs at the centre of decision-making but supports managing natural systems for long-term sustainability.

The appeal to nature fallacy is the assumption that because something is "natural," it must be inherently good or correct, and if something is "unnatural," it must be bad or wrong.

Aquaculture is the controlled farming of aquatic organisms like salmon, tilapia, catfish, oysters and mussels.

Artificial selection, unlike natural selection, is a human-driven process in which specific traits are chosen for breeding in plants and animals.

Autotrophs are organisms that can synthesize their own food from inorganic sources of carbon (typically carbon dioxide, CO₂) and other essential elements.

Bioaccumulation refers to the process by which the concentration of non-biodegradable pollutants increases in an organism over time.

Biocapacity is the capacity of a biologically productive area to continuously provide renewable resources and assimilate the waste generated by human activities.

Biochemical Oxygen Demand (BOD) is a key water quality parameter that measures the amount of dissolved oxygen required by microorganisms to break down organic material in water.

Biodegradability refers to the ability of a substance to be broken down into simpler, harmless substances by natural processes, typically through the action of microorganisms (bacteria, fungi, etc.).

Biodiversity refers to the variety of life in an ecosystem, encompassing different levels of biological organization.

A biogeographic region that has exceptionally high levels of species richness and endemism but is also under significant threat from human activity.

Biogeochemical cycles are the natural pathways through which essential elements like carbon, nitrogen, and phosphorus circulate between the biotic (living) and abiotic (non-living) components of Earth.

Biological mixing is the movement of soil particles and organic matter by organisms.

Biological Oxygen Demand (BOD) measures the amount of dissolved oxygen required by microorganisms to decompose organic matter in water.

Biomagnification refers to the process by which the concentration of non-biodegradable pollutants increases as you move up trophic levels in a food chain or food web.

Biomass is the total mass of living organisms in a given area or volume.

Dry mass is the mass of an organism after all water has been removed.

Biome shift refers to the movement of major vegetation and ecosystem types towards the poles or higher elevations due to long-term climate changes.

A biome is a group of ecosystems that share similar climatic conditions, regardless of their geographic location.

The biosphere is the global ecological system that includes all living organisms and their interactions with the atmosphere, hydrosphere, and lithosphere.

Biosphere integrity refers to the capacity of ecosystems to maintain biodiversity (genes, species, functions) and continue providing essential ecological services.

Biotic factors are the living components of an ecosystem, such as plants, animals, and microorganisms, as well as their interactions.

A biotic index is a quantitative score representing the health of an aquatic system, derived from the composition and abundance of pollution-sensitive and pollution-tolerant organisms.

Bioturbation is the mixing and disturbance of soil by living organisms.

Bottom trawling is an industrial fishing method that drags heavy nets along the seabed, capturing bottom-dwelling species but causing severe damage to habitats and high bycatch rates.

A bromeliad is a type of tropical plant belonging to the Bromeliaceae family, which includes over 3,000 species.

Carbon Capture and Storage (CCS) is a technology that captures CO₂ emissions from industrial processes or power plants and stores it underground in geological formations, such as depleted oil and gas fields or deep saline aquifers.

Carbon neutrality (or climate neutrality) refers to achieving a net-zero carbon footprint by balancing the amount of carbon dioxide emitted with the amount removed from the atmosphere, typically through carbon offset initiatives like reforestation or carbon capture and storage.

Carbon offsetting is compensating for emissions by investing in activities that remove or reduce an equivalent amount of carbon elsewhere.

Carbon sequestration is the process of capturing atmospheric carbon dioxide (CO₂) and storing it in solid or liquid form.

A carbon sink is any natural or artificial system that absorbs more carbon than it releases, thus removing CO₂ from the atmosphere.

A carbon tax is a financial charge placed on the carbon content of fuels, encouraging businesses and individuals to reduce their carbon footprint.

Carnivores are secondary or tertiary consumers that feed on other animals.

Carrying capacity is the maximum number of individuals of a species that an environment can sustainably support over time.

Cation-exchange capacity (CEC) is the ability of a soil to hold positively charged ions due to negatively charged particles like clays and humus.

Cellular respiration is the conversion of stored chemical energy in glucose into a usable chemical form that fuels metabolic processes in living cells.

Cellular respiration is the process by which organisms break down glucose (a type of sugar) into energy that can be used by cells to carry out various active processes.

Chemoautotrophs are organisms that use inorganic chemical reactions to obtain energy, typically through exothermic reactions, to drive the process of chemosynthesis.

The circular economy is an economic model that decouples economic growth from resource consumption by keeping materials, products, and resources in use for as long as possible.

Citizen science is the involvement of the general public in scientific research, particularly in collecting, analyzing, and reporting data on environmental systems.

A clade is a group of organisms that includes a common ancestor and all its descendants.

Cladistics is the branch of biology that classifies organisms according to their evolutionary relationships, not just physical similarities.

Cladistics is a method of classification based on evolutionary history rather than just physical similarities.

Classification is the systematic arrangement of organisms into groups based on shared characteristics.

Climate describes the average weather conditions in a region over a long period, typically 30 years or more.

Climate justice refers to the fair treatment of all people and countries in policies and impacts related to climate change. It recognises that those who contributed least to the problem are often the most affected.

Climate justice emphasizes fairness, ensuring those who contribute the least to climate change are not the ones who suffer the most.

A climax community is the final, stable community in succession, in equilibrium with its environment and characterized by high biodiversity, complex food webs, and efficient nutrient cycling.

Closed systems are systems that exchange energy but not matter with their surroundings.

The force of attraction between molecules of the same substance (in this case, water).

A community is a collection of interacting populations of different species living in the same area and at the same time.

Competition occurs when two or more organisms require the same limited resource, resulting in a negative effect on all participants’ growth, survival, or reproduction.

Compost is partially decomposed organic matter produced from kitchen, garden, and farm waste.

Consequentialist ethics is a moral theory that judges the morality of an action based solely on its consequences.

Consumers are organisms that obtain energy by feeding on other organisms.

Consumers are organisms that obtain chemical energy by consuming other organisms or organic material.

Coral bleaching is when corals expel the symbiotic algae living within their tissues due to stress from heat, pollution, or acidification, causing them to turn white.

A critical threshold is the moment at which a system crosses a boundary, triggering rapid state change.

Cultural value encompasses the tangible and intangible aspects of nature that shape traditions, languages, and knowledge systems.

An area in a water body where oxygen levels are too low to sustain most marine life

Decarbonization refers to the process of reducing or eliminating carbon dioxide (CO₂) emissions from energy production, transportation, industry, and other sectors.

Decomposers, such as fungi and bacteria, are organisms that break down organic matter into simpler substances.

Decomposition is the breakdown of organic nitrogen in dead organisms and waste products into ammonium (NH₄⁺).

Denitrification is the conversion of nitrates (NO₃⁻) back into nitrogen gas (N₂), which is released into the atmosphere.

Density-dependent factors are biotic elements that intensify as population density increases.

The dependency ratio is a measure of the proportion of dependents (people under 15 and over 64) to the working-age population (15–64 years). It is calculated as:

Desalination is the process of removing salt and other impurities from seawater to produce freshwater.

Detritivores are organisms that feed on dead organic matter, such as decaying plants and animals.

The Dichotomous Key is a step-by-step decision-making tool that helps classify an organism based on observable characteristics.

Disease is a biological interaction in which a pathogen (virus, bacterium, fungus, or protozoan) infects a host organism, causing harm or death.

Dissolved Oxygen is the amount of oxygen dissolved in water, essential for aquatic organisms.

The Doughnut Economics model, proposed by economist Kate Raworth, offers a framework to address these challenges by balancing human needs with planetary boundaries.

A dynamic atmospheric system is one in which gases, energy, and particles are continuously transformed and redistributed through interacting physical and chemical processes.

Eco-economic decoupling refers to the process of separating economic growth from environmental degradation.

Ecocentrism is a philosophy that prioritizes the intrinsic value of nature and advocates for minimal human impact on the environment.

Ecological economics is an interdisciplinary field that studies the relationship between economic systems and the environment, recognizing that the economy operates within the Earth's ecological limits.

Ecological efficiency refers to the percentage of energy that is transferred from one trophic level to the next in an ecosystem.

An ecological footprint is the measure of the amount of land and water area required to provide all resources a population consumes and absorb waste and emissions (e.g., CO₂ absorption by forests)

An ecological niche is the unique set of abiotic and biotic conditions and resources that a species requires to survive, grow, and reproduce.

Ecological pyramids are graphical representations used to show the relative numbers, biomass, or energy at different trophic levels in an ecosystem.

Economic growth refers to the increase in the total market value of goods and services produced in a country over time.

Economic sustainability refers to the development of economic structures and systems that allow for the long-term production and consumption of goods and services in a way that meets human needs without depleting natural resources or causing irreversible environmental damage.

Economic value refers to the monetary worth of natural resources and the ecosystem services they provide.

Economics is the study of how humans produce, distribute, and consume goods and services, both at an individual and collective level.

Ecosystem is a geographic area where plants, animals and other organisms, as well as weather and landscape, work together to form a bubble of life

A long-lasting loss of structure, biodiversity, and ecosystem function, where the system shifts to a new, less complex state.

Ecosystem resilience refers to an ecosystem’s ability to recover from disturbances and return to its original state or adapt to a new equilibrium.

Ecosystem services or intangible natural capital are nature’s "free services" that support life and human well-being.

The "warm phase" of the ENSO cycle, characterized by warmer-than-average sea surface temperatures in the eastern tropical Pacific

The El Niño Southern Oscillation (ENSO) is a natural climatic phenomenon involving periodic fluctuations in sea surface temperatures and atmospheric pressure across the tropical Pacific Ocean.

Electromagnetic radiation is energy that travels as oscillating waves through space and includes radio waves, infrared, visible light, ultraviolet, X-rays and gamma rays.

Emergent properties are characteristics or behaviors that arise when individual components interact but are not present in the components themselves.

Endemism refers to species that exist only in one geographic location, such as an island, mountain range, or isolated ecosystem.

Endocrine disruptor is a chemical that interferes with the hormonal system, causing developmental, reproductive, or immune problems.

Energy security refers to a country’s ability to access affordable, reliable, and sustainable energy sources without major disruptions.

The enhanced greenhouse effect refers to additional warming caused by increased concentrations of greenhouse gases from human activities.

Entropy refers to the measure of disorder or randomness within a system.

Environmental accounting (also called green accounting) is the process of assigning economic value to natural resources, environmental degradation, and ecosystem services.

Environmental constitutionalism refers to the integration of environmental rights, responsibilities, and protections into a nation's constitution.

Environmental ethics is a branch of ethical philosophy that deals with the moral relationship between humans and the environment.

An Environmental Impact Assessment (EIA) is a critical tool for ensuring that development projects are sustainable and that their potential environmental, social, and economic impacts are fully considered before they are approved and implemented.

Environmental justice is the principle that all people, regardless of race, gender, socioeconomic status, or nationality, have the right to live in a clean, healthy environment and have fair access to natural resources.

Environmental migration refers to the movement of people caused by changes in the environment, which can be either sudden or gradual.

Environmental sustainability refers to the use and management of natural resources in a way that ensures they can be replenished, and ecosystems can recover and regenerate over time.

An environmental value system (EVS) is a framework that shapes how individuals or groups perceive and respond to environmental issues.

Equilibrium refers to a state of balance within a system.

Erosion is the removal of soil particles by wind or water.

Ethics is a branch of philosophy that examines moral principles and determines what behaviors are right or wrong.

Eutrophication is a process where excess nutrients, primarily nitrates and phosphates, enter aquatic ecosystems, triggering a cascade of ecological changes.

Evaporation is the transformation of liquid water into vapour due to solar heating.

Evolution is the cumulative change in the heritable characteristics of a population over generations.

An oceanic area extending 200 nautical miles from a country’s coastline where that nation has exclusive rights over marine resource use.

The First Law of Thermodynamics states that energy cannot be created or destroyed. It only changes from one form to another, maintaining a constant total amount.

A fish stock refers to a population of a particular species of fish that is managed as a unit. It may include all individuals in a defined geographical area.

A flow is the movement of water between stores either as a transfer or a transformation.

Flows are the processes that move energy, matter, or information within a system.

A food chain is a linear sequence that shows how organic matter and energy flow from one organism to another.

Food miles are a proxy for the carbon emissions associated with the movement of food through the supply chain.

Food security is defined as the physical and economic availability of food, ensuring all individuals can access the balanced diet necessary for a healthy and active life.

Food webs are networks of interconnected food chains that show how energy and matter flow through an ecosystem.

Fossils are preserved remains, traces, or imprints of ancient organisms found in sedimentary rocks.

The fundamental niche is the full range of conditions and resources a species could theoretically use if there were no competition, predators, or other limiting factors.

Gross Domestic Product (GDP) is a common indicator of economic development that measures the monetary value of all final goods and services produced within a country over a specific period.

Genetic diversity is the variety of genes within a species, allowing for adaptation to environmental changes.

Genetic recombination refers to the random mixing of parental genes during meiosis and fertilization, creating genetically unique offspring.

Intentional, large-scale modification of the climate system to counteract global warming, usually without reducing emissions at the source.

Ghost fishing is the unintended capture and death of marine organisms caused by lost or abandoned fishing gear that continues to function passively in the environment.

Gleying is the formation of waterlogged soils due to prolonged saturation, resulting in greyish or bluish colours.

Green architecture refers to the design, construction, and operation of buildings in an environmentally responsible and resource-efficient manner throughout their life cycle.

Green GDP is a measure of economic development that adjusts traditional GDP by subtracting environmental costs, such as deforestation and air pollution.

The greenhouse effect is a natural warming process where greenhouse gases absorb and re-emit infrared radiation, preventing heat from escaping into space.

Greenhouse gases are atmospheric gases that absorb infrared radiation emitted from the Earth’s surface and re-radiate it back, contributing to atmospheric warming.

Greenwashing (or "green sheen") refers to misleading marketing strategies used by companies to appear more environmentally friendly than they actually are.

Greywater recycling is the process of collecting, treating, and reusing household wastewater from showers, sinks, and washing machines for non-potable uses like flushing toilets and landscape irrigation.

Gross domestic product (GDP) is a monetary measure of all final goods and services produced within a country in a given time period (usually a year).

Gross Primary Productivity (GPP) refers to the total amount of energy captured by producers (typically plants and algae) through photosynthesis.

Gross Productivity (GP) refers to the total amount of biomass produced by an organism or a trophic level over a given period of time.

Groundwater flow is the horizontal movement of water through saturated soil or rock layers.

A gyre is a large, rotating system of ocean currents that collects floating materials such as plastics into central “garbage patches.”

Habitable land is land not covered by glaciers or classified as barren, and that can support ecosystems and human use.

A habitat is the physical location where a species lives and interacts with its environment.

Habitat diversity is the range of different habitats present in an ecosystem or within a geographical area.

The Hadley cell is the largest and strongest atmospheric circulation cell, driven by intense heating at the equator and responsible for tropical climates and the formation of deserts in the subtropics.

Half-life is a scientific term used to describe the time it takes for half of a given quantity of a substance to degrade or transform into another substance.

Health value refers to the benefits nature provides for human health, both physically and mentally.

Herbivores are animals that feed primarily on plants or algae.

Herbivory is an interaction in which an animal (the herbivore) feeds on a plant or algal species (producer) for energy and nutrients.

Heterotrophs are organisms that cannot synthesize their own food. Instead, they obtain carbon compounds (such as glucose, proteins, and lipids) by consuming other organisms—either autotrophs (plants and algae) or other heterotrophs (animals, fungi, etc.).

Hindcasting is a method for validating climate models by comparing their simulated past climate with actual historical records.

Human carrying capacity is the maximum number of people Earth can support indefinitely, given current technology and lifestyle choices.

Humus is a dark, crumbly substance that retains waterand nutrients, improving soil fertility.

Hypoxia is a condition of severely reduced dissolved oxygen in a body of water.

Ice cores are cylinders of ice drilled from glaciers or ice sheets that contain trapped gases and particles from past atmospheres.

Identification in taxonomy means determining the species of an individual organism using various tools and methods.

Indicator species are organisms whose presence, absence, or abundance provides information about environmental conditions, particularly pollution levels.

An individual is a single organism, such as a lion, a pine tree, or a bacterium.

Infiltration is the process by which water enters the soil from the surface.

Intrinsic value refers to the worth of something independent of its usefulness to humans.

Instrumental value refers to the usefulness of an entity for humans. This value is based on how nature benefits humans directly or indirectly.

Invasive alien species are non-native organisms that, when introduced to a new ecosystem, can cause significant harm to local biodiversity.

An isolated system exchanges neither energy nor matter with its surroundings.

Isotopes are atoms of the same element with different neutron counts; ratios shift with temperature, enabling paleoclimate reconstruction.

The International Union for Conservation of Nature (IUCN) is the global authority on the conservation status of species.

Species that reproduce slowly, producing few offspring but investing heavily in their survival.

Key Biodiversity Areas (KBAs) are sites that have been prioritized for conservation due to their exceptional ecological value.

A keystone species is an organism that has a disproportionately large impact on its ecosystem relative to its population size.

A kite diagram is a graphical representation of species distribution along a transect.

The "cool phase" of the ENSO cycle, characterized by cooler-than-average sea surface temperatures in the eastern tropical Pacific.

Latent heat of vaporization is the amount of energy required to convert 1 kg of liquid to vapor without a change in temperature.

Laws are rules that govern human behavior and are enforced by social or governmental authority.

Leaching is the downward movement of dissolved minerals and nutrients through the soil.

Legal personhood refers to the capacity to have legal rights, to sue, and to be sued in a court of law.

Limestone is a sedimentary rock composed primarily of CaCO₃, formed through both biological and chemical precipitation processes.

Limiting factors are conditions that restrict population growth.

The Lincoln Index is a mathematical formula used to estimate the size of a population based on a capture-mark-release-recapture method.

Long-term climate data refers to environmental measurements collected over several decades or centuries, allowing patterns and trends related to climate change to be identified and analysed.

Low-productivity food systems are farming methods that maintain high environmental sustainability but generate relatively small amounts of food.

Macrophytes are large aquatic plants visible to the naked eye.

Malnutrition is the condition of having an inadequate or unbalanced diet, including both insufficient intake (undernourishment) and excessive intake (overnourishment).

Marginalized groups are communities with limited political power, limited resources, or restricted legal rights.

Marine Protected Areas (MPAs) are designated regions of the ocean where human activities, such as fishing and resource extraction, are restricted or prohibited to conserve marine ecosystems and biodiversity.

Mass extinctions are catastrophic events that lead to the widespread loss of species, dramatically reshaping ecosystems.

Maximum sustainable yield (MSY) is the largest amount of biomass that can be harvested from an ecosystem without depleting its resources, ensuring long-term sustainability.

The Maximum Sustainable Yield (MSY) is the highest possible annual catch that can be harvested indefinitely without depleting a fish population.

Metering is the installation of devices that record the volume of water used, enabling efficient monitoring and billing.

Methane clathrates are ice-like structures that trap methane molecules within a lattice of water molecules.

Methanogenesis is the biological process by which methanogenic archaea (bacteria-like microorganisms) produce methane (CH₄) from organic material in anaerobic environments.

Methanotrophs are microorganisms that use methane as a carbon and energy source, reducing methane emissions from soils.

Microplastics are small plastic particles, typically less than 5 millimeters in diameter, that result from the breakdown of larger plastic waste or are intentionally manufactured at that size.

Milankovitch cycles are long-term variations in Earth’s orbital geometry and axial behaviour that alter solar radiation distribution and drive natural climate cycles such as ice ages and interglacial warm periods.

Mitigation is any strategy that reduces or prevents greenhouse gas emissions, including transitioning to renewable energy, increasing energy efficiency, and reducing industrial emissions.

A model is a simplified representation of reality used to understand how a system works and predict how it will respond to change.

Mollisols are deep, nutrient-rich soils formed under temperate grasslands, known as some of the most agriculturally productive soils in the world.

An artificial system growing a single species of crop with minimal biodiversity, resulting in low resilience.

Moral standing refers to the idea that an entity (whether living or non-living) has moral significance and should be considered when making decisions about how we interact with it.

A mutation is a random change in DNA that introduces new genetic variants (alleles).

Mutualism is a symbiotic relationship between two different species in which both organisms benefit from the interaction.

A mutualistic nitrogen-fixing relationship is a symbiotic interaction between plants and nitrogen-fixing bacteria, where both organisms benefit.

Natural capital refers to the total stock of natural resources (both renewable and non-renewable) that provide ecosystem services benefiting humans and the environment.

Natural resources are materials and energy sources found in nature that humans use to meet their needs.

Natural selection is the process by which populations evolve over generations due to genetic variation, competition, and differential survival and reproduction.

Natural selection is the primary mechanism behind evolutionary change, shaping species over time and leading to the incredible biodiversity we see on Earth today.

Negative feedback loops are processes where the output of a system acts to reduce or reverse changes, helping the system maintain stability.

Net Primary Productivity (NPP) refers to the amount of carbon that is captured by plants through photosynthesis and is available for growth and reproduction after subtracting the energy used by the plants for cellular respiration.

Net Productivity (NP) is the amount of biomass remaining after the losses due to cellular respiration have been subtracted from the gross productivity.

A niche describes the role of a species in its environment, including how it interacts with biotic (living) and abiotic (non-living) factors.

Nitrification is the conversion of ammonia (NH₃) to nitrates (NO₃⁻).

The nitrogen cycle is a biogeochemical cycle through which nitrogen is transferred and transformed between the atmosphere, biosphere, hydrosphere, and lithosphere, ensuring its continued availability to living organisms.

Nitrogen fixation is the conversion of nitrogen gas (N₂) from the atmosphere into ammonia (NH₃).

$NO_x$ refers to a group of gases consisting of nitrogen dioxide ($NO_2$) and nitric oxide ($NO$).

Nomadic pastoralism is a traditional agricultural system where people move their livestock, such as sheep, goats, or camels, seasonally to find pasture and water

Non-commercial cropping refers to farming practices that are not focused on profit but on self-sufficiency and local community needs.

Non-renewable natural capital is a resource that exists in finite amounts and cannot be replenished within a human lifespan.

Nutrient cycling is the movement of nutrients like nitrogen, phosphorus, and carbon through the soil, plants, and atmosphere.

Nutrient loading refers to the addition of nutrients (natural or human-induced) into a water body, affecting productivity.

Nutrient mixing refers to the vertical movement of water that redistributes dissolved nutrients (like nitrates and phosphates) throughout the water column.

Obliquity refers to the angle of Earth’s axial tilt, which determines how strongly sunlight is concentrated at different latitudes.

Ocean acidification is the process by which the ocean becomes more acidic due to increased levels of dissolved carbon dioxide.

Ocean currents are large-scale movements of water driven by winds, temperature, salinity differences, and Earth’s rotation that transport heat across the planet.

Omnivores consume both plants and animals, allowing them to occupy multiple trophic levels.

An open system is one in which energy and matter can enter and exit freely, allowing interaction with the surrounding environment.

Open systems are systems that exchange both energy and matter with their surroundings.

Oxisols are ancient, deeply weathered tropical soils with low natural fertility and strong nutrient leaching.

Ozone (O₃) is a reactive form of oxygen composed of three oxygen atoms that absorbs harmful ultraviolet radiation from the Sun.

The ozone layer is a concentration of ozone molecules located in the stratosphere that protects living organisms from harmful ultraviolet radiation.

Ozone-depleting substances (ODSs) are chemicals that accelerate ozone destruction beyond natural levels.

Parasitism is a symbiotic relationship where one organism (the parasite) benefits by living on or within another organism (the host) and obtaining nutrients from it, usually without immediately killing the host.

The Passive House (Passivhaus) concept is an architectural approach that significantly reduces energy consumption for heating and cooling by maximizing natural insulation, ventilation, and solar gain.

Peat is a dense, carbon-rich accumulation of partially decomposed plant material found in waterlogged ecosystems.

Percentage frequency measures how often a species appears in the sampled quadrats.

Percolation is the downward movement of water through soil layers.

Permaculture is a holistic farming system designed to mimic natural ecosystems.

A perspective is a point of view that reflects how an individual perceives and understands the world, based on their beliefs, values, and lived experiences.

pH measures hydrogen ion concentration, influencing chemical reactions in water.

The photic zone is the upper layer of a body of water that receives enough sunlight to support photosynthesis.

Photoautotrophs are organisms that use light as their external energy source to synthesize carbon compounds (e.g., glucose) through the process of photosynthesis.

Photochemical smog is a type of air pollution that forms when primary pollutants, such as nitrogen oxides (NOx) and volatile organic compounds (VOCs), undergo chemical reactions in the presence of sunlight, resulting in the creation of harmful secondary pollutants like peroxyacyl nitrates (PANs) and tropospheric ozone.

Photosynthesis is the conversion of light energy into chemical energy in the form of glucose, which can later be stored as biomass or used as fuel by autotrophs.

Phytoplankton are microscopic organisms capable of photosynthesis

Plagiomax is an ecosystem that is arrested in an earlier stage of succession due to human interference.

A planetary boundary is a threshold beyond which human activities risk causing catastrophic environmental change.

A planetary boundary is a scientifically defined threshold beyond which human activities risk causing abrupt or irreversible environmental change.

The Planetary Health Diet (PHD) is a scientifically grounded dietary pattern that supports both human health and the planet’s ecological limits.

Ice-based clouds that form only at extremely low stratospheric temperatures and enable reactions that convert stored chlorine into ozone-destroying radicals.

Polarity refers to the uneven distribution of electrical charge in a molecule, leading to regions of slight positive and negative charge.

A population is a group of individuals of the same species in an area.

Density is the number of individuals per unit area.

Population distribution refers to how individuals of a species are spread across their habitat.

Population momentum refers to continued population growth even if the fertility rate declines.

Positive feedback loops are processes that exacerbate the effects of a small disturbance.

The pre-biotic atmosphere refers to Earth’s early atmosphere before life evolved, dominated by CO₂, methane, and nitrogen, and lacking oxygen.

Predation is an interaction in which one organism (the predator) kills and consumes another organism (the prey) for food.

Pressure gradient force is the force that drives air movement due to differences in atmospheric pressure.

Primary productivity is the rate of production of biomass using an external energy source and inorganic sources of carbon and other elements.

Primary productivity refers to the rate at which phytoplankton and aquatic plants convert sunlight and nutrients into organic matter through photosynthesis.

Producers, also known as autotrophs, are organisms that can produce their own food using photosynthesis (or chemosynthesis in some cases).

Pumped hydroelectric storage is a method used to store energy by moving water between two reservoirs at different elevations.

The Quaternary Period is the geological time span from 2.58 million years ago to the present, marked by repeated cycles of glaciation and interglacial warming.

Species that reproduce rapidly, producing many offspring with little parental care.

Radiative forcing measures the change in Earth’s energy balance caused by greenhouse gases, influencing global temperature.

Radiative forcing describes how different factors, such as GHGs, aerosols, and albedo, alter the balance of heat in Earth’s atmosphere.

A rainforest is a dense, lush forest characterized by high rainfall (typically over 2,000 mm per year) and rich biodiversity.

A method where each individual in the population has an equal and independent chance of being selected for the sample.

A realized niche is the actual conditions in which a species exists due to competition, predation, and environmental constraints.

A marine algal bloom, often reddish-brown, caused by dinoflagellates producing potent neurotoxins.

Renewable natural capital is a resource that regenerates naturally over time and provides ongoing benefits.

Reproductive isolation is the prevention of gene flow between populations due to physical, ecological, or behavioral barriers.

The average time a molecule remains in the atmosphere before being removed through physical or chemical processes.

Residence time is the average duration that a carbon atom remains in a particular store before moving to another part of the carbon cycle.

Resilience is a system’s ability to resist disturbances, recover, and maintain stability instead of reaching a tipping point that leads to a new equilibrium.

Resource security refers to the availability of natural resources in sufficient quantities to meet the needs of a population while ensuring long-term sustainability.

Rewilding is a conservation strategy aimed at restoring natural processes and ecosystem functions by reducing human intervention and allowing nature to regenerate.

Rights-based ethics (also known as deontological ethics) evaluates morality based on whether an action respects the rights of individuals or entities, rather than its consequences.

Rural–urban migration is the movement of people from rural areas (countryside) to urban areas (cities and towns) in search of better opportunities.

The Second Law of Thermodynamics states that in any energy transformation, some of the energy is lost as heat and becomes less available to do useful work.

Secondary productivity refers to the gain in biomass by consumers (such as herbivores, carnivores, and omnivores) through the assimilation of carbon compounds from the food they ingest.

A seed bank is a natural store of viable seeds present in the soil, capable of germinating when favorable conditions arise.

Selective pressure refers to any environmental factor (natural or human-made) that influences which traits are favorable for survival and reproduction in a population.

A seral community (sere) is a stage in the process of succession, where one community modifies the environment, making it more suitable for the next community.

Sewage treatment refers to the multi-stage process that removes solid waste, organic matter, nutrients, and pathogens from wastewater before discharge into the environment.

Simpson’s Reciprocal Index (D) is a quantitative measure of species diversity, used to: compare biodiversity between different ecosystems, monitor changes in biodiversity over time within a specific area and assess ecosystem health,

A sink is a location in an ecosystem where a chemical element is accumulated or stored over time, leading to a net increase in that element in that location.

Social mix refers to creating urban areas where people from different social, economic, and cultural backgrounds live and interact.

Social sustainability refers to the development and maintenance of structures and systems that support human well-being, ensuring that societies remain stable, inclusive, and resilient over time.

Societal resilience refers to the ability of communities to prepare for, absorb, recover from and adapt to climate-related hazards.

Soil is a dynamic system that interacts with the atmosphere, hydrosphere, biosphere, and lithosphere.

A soil catena is a series of distinct but related soils arranged along a slope, formed from the same parent material under varying microclimatic and drainage conditions.

Soil conservation is the sustainable management of soil to prevent degradation, maintain fertility, and support long-term agricultural productivity.

A soil profile is a vertical section of soil that reveals distinct horizons, each formed by long-term interactions of organic and inorganic materials.

Soil texture refers to the proportion of sand, silt, and clay in the soil.

Soil texture refers to the relative proportions of sand, silt, clay, and humus in a soil sample.

Solar Radiation Management (SRM) is a form of geoengineering designed to reflect sunlight away from the Earth to reduce warming.

Solid Domestic Waste (SDW) refers to non-liquid waste generated from households and residential areas.

A source is a location or process in which a chemical element is released into the environment, leading to a net increase in the amount of the element in the atmosphere or other parts of the ecosystem.

Speciation is the process by which new species evolve from an existing population due to isolation and adaptation.

A species is a group of organisms that can interbreed and produce fertile offspring under natural conditions.

Abundance refers to the total number of individuals of a species within a quadrat.

Species diversity is the variety of species in an ecosystem, including both species richness (the number of species) and species evenness (the relative abundance of each species).

Species evenness is the relative abundance of each species in a community.

Species richness is the total number of different species present in a community.

Specific heat capacity is the amount of energy needed to raise the temperature of 1 gram of a substance by 1°C.

Stability is the ability of an ecosystem to maintain structure and function over time, even in the face of stress or disturbances.

A stakeholder is any person, group or institution that has an interest in or is affected by climate change and may influence decisions related to it.

The standard lapse rate refers to the rate of temperature decrease with height.

Steady-state equilibrium is the condition in which inputs equal outputs over time, even though water is continuously moving between stores.

Stores are places where water accumulates or is held temporarily, such as oceans, glaciers, lakes, or groundwater.

Stores are components in the ecosystem where elements are held for relatively long periods.

Stratification is a common phenomenon in aquatic ecosystems, where water forms distinct layers due to differences in temperature and density.

A strong sustainability model is a sustainability model that depicts the environment as a foundation that supports both society and the economy.

Suburbanization is the movement of people from dense urban centers to lower-density areas on the outskirts of cities, known as suburbs.

Succession is the gradual process of change in ecosystems, where one community replaces another due to shifts in biotic and abiotic conditions.

Sustainability is the natural capacity of ecosystems to maintain equilibrium between resource inputs and waste outputs while continuing to support life.

Sustainability indicators are quantitative measures that help us assess the health and viability of systems across environmental, social, and economic dimensions.

Sustainability models are simplified representations of reality that help us understand how environmental, social, and economic factors interact in sustainable development.

Sustainable development refers to meeting the needs of the present without compromising the ability of future generations to meet their own needs.

Sustainable diet refers to eating patterns that support human health while maintaining the planet’s capacity to provide food for future generations.

The sustainable yield is the maximum amount of water that can be withdrawn from the system without reducing its capacity to regenerate.

Synapomorphies are traits shared by members of a clade that evolved from a common ancestor, distinguishing them from other groups.

Synthetic (inorganic) fertilizers are industrially manufactured chemical compounds that supply essential plant nutrients, typically nitrogen, phosphorus, and potassium.

A system is a set of interacting or interdependent components that work together to form a functional whole.

A method where a random starting point is chosen, and then every k-th element is selected from a list until the desired sample size is reached.

A systems approach is a way of looking at complex situations by focusing on the interactions and interdependencies between different components within a system.

A system diagram is a visual representation that shows how different components of a system interact with each other.

A taxon (plural taxa) is any group of organisms that shares common characteristics and has been given a rank in the taxonomic hierarchy.

Technocentrism is a worldview that sees technology and human innovation as the primary solutions to environmental problems.

Technological value refers to the potential of natural resources to inspire innovations and advancements.

The Haber process is an industrial method used to produce ammonia (NH₃) from atmospheric nitrogen (N₂) and hydrogen (H₂).

A thermocline is a layer in a body of water where temperature decreases sharply with depth, restricting vertical movement and mixing.

A tipping point is a critical threshold where small changes trigger dramatic, often irreversible shifts in an ecosystem.

A tipping point is the minimum change in a system that destabilizes it and shifts the regime to a new equilibrium or stable state.

Topsoil is the upper mineral-organic layer of soil where most nutrient cycling, decomposer activity, and root growth occur.

Traditional harvesting refers to methods used by Indigenous and local communities that maintain long-term ecosystem productivity without permanent land conversion.

Traditional Indigenous land management refers to ecologically sustainable practices that ensure long-term environmental balance through cultural knowledge, adaptive management, and minimal ecological disturbance.

The tragedy of the commons describes a situation where individuals or nations overuse a shared resource for personal gain, causing long-term harm to the whole group.

The tragedy of the commons is a concept that describes the overexploitation of shared resources due to the tension between individual self-interest and the collective good of sustainable management.

A transect is a straight line or path across an environmental gradient along which samples are taken at regular intervals.

Transfers involve the movement of matter or energy from one place to another without changing its form.

Transformations involve a change in the chemical nature, state, or energy type of matter or energy.

Transpiration is the release of water vapour by plants into the atmosphere.

The tricellular model of atmospheric circulation explains the global movement of air and how it influences temperature, precipitation, and the distribution of biomes.

A trophic level is the feeding position of an organism within a food chain or web, based on how it obtains its energy and nutrients.

Tropical cyclones are rapidly rotating storm systems that develop over warm ocean waters in the tropics.

Turbidity measures water transparency based on suspended particles (sediments, plankton, pollutants).

Turbidity is the cloudiness of water caused by suspended solids or plankton.

The UN Convention on the Law of the Sea (UNCLOS) is a comprehensive international treaty that governs the use and management of the world's oceans.

The UN Sustainable Development Goals (SDGs) are a set of 17 global goals established in 2015 to address social, economic, and environmental challenges by 2030.

UNFCCC is the foundational global treaty established in 1992 to coordinate international climate action.

Upwelling refers to the vertical movement of deep, cold, nutrient-rich water to the surface due to the displacement of surface waters by wind.

An urban area is a built-up region characterized by high population density, extensive infrastructure, and concentrated human activities.

Urban planning is the process of designing and managing land use in cities and towns to ensure they meet the needs of their populations while promoting sustainable development.

Urbanization refers to the population shift from rural to urban areas, leading to an increase in the proportion of people living in cities and towns.

Values are qualities, principles, or standards that individuals and communities consider important in life.

Values surveys are structured questionnaires designed to explore the beliefs, priorities, and attitudes of individuals or groups.

Variation refers to the differences in traits among individuals of a population, resulting from genetic and environmental factors.

Virtue ethics is an ethical theory that emphasizes the character and moral virtues of the individual making the decision, rather than focusing on the consequences of their actions or their adherence to specific rules.

VOCs are a diverse group of organic chemicals that easily vaporize into the atmosphere.

A water footprint refers to the total volume of freshwater used to produce goods and services consumed by an individual, community, or nation.

Water pollutants are substances or forms of energy that alter the physical, chemical, or biological characteristics of water, making it harmful for organisms and ecosystems.

Water pollution is the contamination of water bodies by harmful substances, making them unsafe for humans, wildlife, and ecosystems.

Water quality is a measure of the chemical, physical, and biological characteristics of water, determining its suitability for human consumption, agriculture, industry, and aquatic ecosystems.

The water quality index is a composite measure representing overall water quality, calculated by combining the results of several water tests with assigned weightings.

The water quality index is a weighted average of different water quality parameters.

Water scarcity refers to the limited availability of water to meet the needs of human societies.

Water security is the availability of an adequate quantity and quality of water to meet the needs of people and ecosystems.

Water stress is defined as a situation in which the clean, accessible water supply falls below 1,700 cubic meters per year per capita.

A weak sustainability model is a sustainability model that shows overlapping relationships between the three pillars: environment, society, and economy.

Weather refers to the temporary state of the atmosphere in a specific place and time.

Weathering is the process of breaking down rocks and minerals into smaller particles, forming the inorganic component of soil.

A worldview is a shared framework of beliefs, values, and assumptions that shapes how a group of people understands and interacts with the world.

Zero tillage (or no-till farming) is a method of farming where the soil is left undisturbed, except for minimal planting.

Zonation refers to the gradual change in species composition along an environmental gradient.