Sustainability Glossary

The total amount of greenhouse gases (including carbon dioxide and methane) that are generated by our actions. Typically measured in units of carbon dioxide equivalent (CO₂e), a carbon footprint can be calculated for individuals, organizations, events, or products throughout their lifecycle.

An economic system aimed at eliminating waste and the continual use of resources. Unlike the traditional linear economy (make, use, dispose), a circular economy is based on three principles: design out waste and pollution, keep products and materials in use, and regenerate natural systems.

A reduction in emissions of carbon dioxide or other greenhouse gases made in order to compensate for emissions made elsewhere. Offsets are typically achieved through investment in renewable energy, reforestation, or energy efficiency projects. One carbon offset equals one metric ton of CO₂ or its equivalent.

Achieving net-zero carbon emissions by balancing the amount of greenhouse gases produced with an equivalent amount removed from the atmosphere. This is accomplished through a combination of emissions reductions and carbon offsetting strategies.

Energy derived from sources that produce little to no greenhouse gas emissions or pollutants. This includes renewable sources like solar, wind, hydropower, and geothermal, as well as non-renewable low-emission sources like nuclear energy. Clean energy is essential for combating climate change.

Long-term shifts in global or regional climate patterns, primarily driven by human activities that increase atmospheric concentrations of greenhouse gases. Key effects include rising temperatures, extreme weather events, sea level rise, and ecosystem disruption.

A business model that helps a company be socially accountable to itself, its stakeholders, and the public. CSR encompasses a company's efforts to improve society through ethical practices, environmental stewardship, philanthropy, and volunteerism.

A design philosophy and certification framework that mimics nature's processes, where waste does not exist. Products are designed so materials can be continuously cycled — either biologically (composting) or technically (recycling) — at the end of their useful life.

The strategic placement of windows, skylights, light shelves, and other architectural features to maximize natural light in buildings. Effective daylighting reduces the need for artificial lighting, saves energy, and improves occupant well-being and productivity.

The process of reducing or eliminating carbon dioxide emissions associated with energy production and consumption. This involves transitioning away from fossil fuels toward low-carbon and zero-carbon energy sources, improving energy efficiency, and adopting carbon capture technologies.

The practice of reducing the amount of energy required to provide products and services, or using less energy to achieve the same outcome. Improving energy efficiency is one of the most cost-effective ways to reduce greenhouse gas emissions and lower operational costs.

A systematic assessment of energy flows and energy use in a building, facility, or process to identify opportunities for improving energy efficiency. Audits typically include site inspections, data analysis, and recommendations for cost-effective energy savings measures.

A set of standards for a company's operations used by socially conscious investors to screen potential investments. Environmental criteria evaluate a company's impact on the planet. Social criteria examine relationships with employees, suppliers, communities. Governance focuses on leadership, executive pay, audits, and shareholder rights.

The global shift from fossil fuel-based energy systems to sustainable, renewable energy systems. This transition encompasses technological innovation, policy reform, infrastructure development, and behavioral change needed to create a low-carbon energy future.

A structure designed, built, operated, and demolished using resource-efficient and environmentally responsible practices. Green buildings minimize environmental impact through energy efficiency, water conservation, sustainable materials, improved indoor air quality, and waste reduction.

A rooftop that is partially or completely covered with vegetation planted over a waterproofing membrane. Green roofs provide insulation, reduce stormwater runoff, mitigate urban heat island effects, create habitat for wildlife, and extend roof lifespan.

Gases in Earth's atmosphere that trap heat, contributing to the greenhouse effect. Major GHGs include carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and fluorinated gases. Human activities have significantly increased atmospheric concentrations of these gases, driving climate change.

Heat energy generated and stored in the Earth's core, crust, and mantle. Geothermal energy can be harnessed for direct heating applications or electricity generation using underground hot water and steam sources. It provides a constant, reliable renewable energy supply.

Electricity generated by harnessing the energy of flowing or falling water. Hydroelectric power is one of the oldest and most widely used renewable energy sources, typically produced at dams that channel water through turbines connected to generators.

A device that transfers heat from one location to another using a refrigeration cycle, providing both heating and cooling. Heat pumps move thermal energy rather than generating it, making them 3-4 times more efficient than conventional resistance heating systems.

A measurable value that demonstrates how effectively a company is achieving key sustainability objectives. In green tech, common KPIs include energy consumption per unit, carbon emissions reduction percentage, renewable energy percentage, and waste diversion rate.

Leadership in Energy and Environmental Design (LEED) is the world's most widely used green building rating system, developed by the U.S. Green Building Council. Buildings earn points across categories like energy efficiency, water savings, materials selection, and indoor environmental quality to achieve Certified, Silver, Gold, or Platinum certification.

A methodology for assessing environmental impacts associated with all stages of a product's life — from raw material extraction through materials processing, manufacture, distribution, use, maintenance, and disposal or recycling. LCA helps identify opportunities for reducing environmental impact.

A localized group of electricity sources and loads that normally operates connected to and synchronous with the traditional wide-area synchronous grid, but can also disconnect to operate autonomously. Microgrids often incorporate renewable energy sources and energy storage for enhanced resilience.

A state where the amount of greenhouse gases produced equals the amount removed from the atmosphere within a specified time period. Achieving net zero requires maximizing emissions reductions first, then offsetting any remaining emissions through carbon removal technologies or verified offset projects.

A legally binding international treaty on climate change adopted in 2015 by 196 parties. The agreement aims to limit global warming to well below 2°C, preferably to 1.5°C, compared to pre-industrial levels. Countries submit Nationally Determined Contributions (NDCs) outlining their emission reduction targets.

A rigorous, voluntary building standard for energy efficiency and comfort. Passive Houses use ultra-insulation, airtight construction, high-performance windows, and heat recovery ventilation to reduce heating and cooling energy requirements by up to 90% compared to conventional buildings.

The conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect. PV cells are the fundamental building blocks of solar panels, converting sunlight directly into direct current (DC) electricity. Modern PV systems are used in residential, commercial, and utility-scale applications.

A long-term contract between an electricity buyer and a seller, typically used for renewable energy projects. PPAs allow businesses to purchase clean energy at a fixed rate without making large upfront capital investments in on-site generation, providing predictable energy costs and supporting renewable energy development.

The process of converting waste materials into new materials and objects. Recycling reduces the need for raw material extraction, saves energy, and decreases greenhouse gas emissions compared to manufacturing from virgin materials. Common recyclables include paper, plastic, glass, metal, and electronics.

Energy derived from natural processes that are replenished at a rate greater than or equal to their consumption. Major renewable sources include solar, wind, hydroelectric, geothermal, and biomass. Renewable energy produces little to no greenhouse gas emissions during operation.

A market-based instrument that represents the environmental and social attributes of 1 megawatt-hour (MWh) of renewable electricity generation. RECs are tradable and allow organizations to demonstrate their use of renewable energy, even if physically receiving power from the conventional grid.

An electricity network that uses digital communications technology to detect and react to local changes in usage. Smart grids enable two-way communication between utilities and consumers, integrate renewable energy sources, support demand response programs, and improve grid reliability and efficiency.

Radiant light and heat from the Sun harnessed using various technologies. The three main types are photovoltaics (PV) for electricity generation, concentrated solar power (CSP) for thermal energy, and solar heating for direct heat applications. Solar is the most abundant renewable energy source on Earth.

The ability to maintain or support a process continuously over time. In environmental contexts, it refers to meeting human needs without compromising the ability of future generations to meet theirs. The three pillars of sustainability are environmental protection, social equity, and economic viability.

Strategies to manage rainwater runoff from developed areas to prevent flooding, reduce pollution, and replenish groundwater. Sustainable approaches include permeable pavements, bioswales, rain gardens, and green roofs that mimic natural water absorption patterns.

A sustainability framework that considers three dimensions of performance: People (social equity), Planet (environmental stewardship), and Profit (economic viability). TBL argues that companies should commit to focusing on social and environmental responsibility just as heavily as on maximizing profits.

An urban area that is significantly warmer than its surrounding rural areas due to human activities and built infrastructure. Dark surfaces like asphalt and concrete absorb and retain heat, while reduced vegetation decreases cooling through evapotranspiration. Green roofs, urban trees, and reflective surfaces can mitigate UHI effects.

Energy harnessed from wind using wind turbines to generate electricity. Wind energy converts the kinetic energy of moving air into mechanical power, which is then converted into electrical power. It is one of the fastest-growing and most cost-effective renewable energy sources worldwide.

The collection, transportation, processing, recycling, and disposal of waste materials. Modern waste management emphasizes the waste hierarchy: prevention, minimization, reuse, recycling, recovery, and disposal. Sustainable waste management aims for zero waste through circular economy principles.

A set of principles aimed at redesigning resource life cycles so all products are reused, and nothing is sent to landfills, incinerators, or the environment. Zero waste seeks to redefine "waste" as a design flaw and emphasizes prevention, responsible production, consumption, reuse, and recovery of products and materials.