Net zero”, “net positive”, “resilient”, “scope 1, 2 and 3”,… explore the glossary to learn about sustainability terms and concepts and how they related to one another.


Navigating the language of environmental sustainability

Climate change is the biggest threat on human health of the 21st Century. As a systemic issue that impacts all aspects of the healthcare sector, a common understanding of key sustainability terms and concepts is essential.

Our glossary provides this foundational knowledge to support the healthcare sector when navigating net zero.


This theme includes vocabulary related to environmental resources, procurement and supply chain, environmental impact, infrastructure and service resilience, and low-carbon care.

  • Carbon cycle

    Carbon cycle is a term used to describe the flow of carbon (in various forms, e.g., as in carbon dioxide) through the atmosphere, ocean, terrestrial biosphere, and lithosphere.

    Reference: International Panel on Climate Change – IPCC

  • Carbon dioxide (CO2)

    A gas consisting of a carbon atom and two oxygen atoms. CO2 occurs naturally in the earth's atmosphere. Its concentration in the atmosphere has risen from 280 parts per million in pre-industrial times to 415 parts per million today. CO2 absorbs and radiates heat, and thereby helps to control the temperature on earth. However, if there is too much CO2 in the atmosphere, temperatures on earth increase.

    CO2 is emitted naturally through volcanoes and hot springs and by humans, principally through the burning of fossil fuels (coal, oil, gas). CO2 is absorbed by plants and trees. Therefore, deforestation also contributes to the increase in CO2 in the atmosphere. CO2 is the most important greenhouse gas in the atmosphere. Other gases such as methane and nitrous oxide are more powerful in terms of absorbing heat, but they are less plentiful and stay remain in the atmosphere for a shorter period of time than CO2.

    Reference: Organisation for Economic Co-operation and Development – OECD

  • Carbon dioxide equivalent (CO2e)

    Carbon dioxide equivalent is a standardized measure of greenhouse gas emissions expressed as equivalents of CO2. Each greenhouse gas has its own global warming potential. Expressing emissions as CO2e involves multiplying the quantity of emissions of a greenhouse gas by its global warming potential. This enables emissions of different types to be compared or added up. Of note, 'carbon' is often used interchangedly for the same meaning.

    "Carbon" is often referred to as meaning CO2e, e.g., in other definitions.

  • Carbon footprint

    Carbon footprint is the estimation of the total amount of greenhouse gases that are emitted into the atmosphere each year by a person, family, building, organization, or company.

    Reference: United States Environmental Protection Agency – US EPA

  • Carbon intensity

    Carbon intensity is the amount of carbon emissions released divided by another unit of measure (for example, such as gross domestic product (GDP), cubic metres, dollars, patient numbers, output energy use or transport).

    Reference: International Panel on Climate Change – IPCC

  • Carbon offseting

    Carbon offset is a reduction in greenhouse gas emissions made as compensation for emissions elsewhere. Offsets can take the form of avoided emissions (e.g., by generating additional renewable energy) or carbon capture (e.g. by planting a forest). Offsets have been criticized, as they may seem to offer organizations the opportunity to avoid reducing their own emissions and continue to produce greenhouse gas emissions.

  • Climate change

    A change in the state of the climate that can be identified (for example, using statistical tests) by changes in the mean and/or the variability of its properties, and that persists for an extended period, typically decades or longer. It refers to any change in climate over time, whether due to natural variability or as a result of human activity.

    Reference: International Panel on Climate Change – IPCC

  • Climate neutral

    Climate neutrality means to bring greenhouse gas emissions of an organization (or individual) down to zero through emissions reductions in their activities or through buying carbon credits to offset their emissions over a specified period of time. Climate neutrality includes all greenhouse gas and harmful substances emitted into the atmosphere by human activity. It can also be referred to as net zero CO2 emissions.

    Reference: United Nations Climate Change – UNFCCC Guide

  • Climate positive

    An organization becomes climate positive when its greenhouse gas removal activity exceeds its greenhouse gas emissions, contributing to a net positive (or carbon negative) effect on the climate.

  • Emission factor

    Emission factors are an expression of how much CO2e is emitted as a result of a certain activity. For example, the amount of CO2e emitted as a result of 1 kWh of electricity use.

  • Onsite power generation

    Onsite power generation refers to producing energy where it is to be consumed, rather than purchasing that energy through the grid. Common benefits of on-site power generation are the reduction of energy cost, reduction of green house gas emissions (especially in the case of renewable energy generation), and improved reliability of supply.

  • Renewable energy; fossil fuels; renewable energy sources

    Renewable energy is energy derived from natural sources that are replenished at a higher rate than they are consumed. Common sources of renewable energy are sunlight, wind, geothermal energy, hydropower, ocean energy and bioenergy. On the other hand, fossil fuels (coal, oil and gas), are non-renewable resources that take hundreds of millions of years to form and that can cause harmful greenhouse gas emissions, such as carbon dioxide.

    Reference: United Nations – UN

  • Environmental impact

    Environmental impact refers to the effect, whether adverse or beneficial, that people or a facility’s activities, products or services has on the environment. Climate change and related events (e.g., pollution, extreme weather, ocean acidification and resource depletion) is a clear example of the impact that human action has on the environment. There are various ways to determine an activity’s environmental impact, such as life cycle assessments, emission inventories and risk assessments.

  • Greenhouse gas protocol emissions scopes (1,2 and 3)

    A recognized standard to categorize organizational sources of GHG emissions. Scope 1 emissions are from sources directly owned or controlled an organization (e.g., onsite fuel combustion in boilers, furnaces, vehicles). Scope 2 are from purchases of electricity, steam, heat, or cooling generated elsewhere.  Scope 3 emissions include indirect emissions caused by an organization's value chain. However, organizations can play an active role in decreasing scope 3 emissions. This includes enhancing the way resources are used (e.g., reduce, reuse), working with suppliers to set engagement targets, and leveraging their purchasing power to demand more sustainable products.

  • Greenhouse Gas Protocol (GHGP)

    The Greenhouse Gas Protocol is "a global standard created for companies and organizations to measure and manage greenhouse gas emissions." It was created by the World Resources Institute and World Business Council for Sustainable Development.

    Reference: Greenhouse Gas Protocol – GHG Protocol

  • Greenhouse gas (GHG)

    Greenhouse gases are those gases that trap heat in the atmosphere, creating global warming. Gases differ by potency as well as how long they stay in the atmosphere. The main greenhouse gas are water vapor, carbon dioxide, methane, ozone, nitrous oxide, and chlorofluorocarbons.

    Reference: United States Environmental Protection Agency – US EPA

  • Global warming

    Global warming is defined by IPCC as an increase in combined surface air and sea surface temperatures averaged over the globe and over a 30-year period. Currently, world leaders have stressed the need to limit global warming to 1.5°C by the end of this century.

    Reference: International Panel on Climate Change – IPCC

  • Global warming potential (GWP)

    Each greenhouse gas has a different rate at which it absorbs heat in the atmosphere. Global warming potential is the heat absorbed by any greenhouse gas in the atmosphere, as a multiple of the heat that would be absorbed by the same mass of carbon dioxide.

  • Models of care - low-carbon care

    A low-carbon model of care is a form of care delivery that is less carbon intensive than alternatives available. It means that the carbon emissions impact of care delivery has been estimated in order to explicitly favor services that are less energy/carbon intensive. Changes to traditional models of clinical care are urgently needed to achieve net-zero. A low-carbon model of care provision will be better at preventing illness, give greater responsibility to patients in managing their health, be leaner in service design and delivery and promote use the lowest carbon technologies (eg. telehealth, app-based).

  • Models of care - prescribing patterns

    Low-carbon prescribing is a term to describe ways of reducing the carbon footprint of medicines through clinicians' prescribing practices. It involves giving information to patients on the best treatment, with the use of the lowest effective dose for the shortest period of time, including drugs that have the smallest carbon footprint. Optimizing medications also involves addressing unnecessary prescribing, which reduces errors. Low-carbon prescriptions also include the use of alternatives such as psychotherapy, social prescribing and lifestyle prescriptions.

  • Net positive

    Net-positive emissions means going beyond net-zero, where the balance of greenhouse gases removed outweighs the amount of greenhouse gases produced.

  • Net zero

    Net zero (emissions) refers to the balance between greenhouse gases produced and removed from the atmosphere. This is achieved by removing an equal amount of emissions to those generated, thereby resulting in zero increase in net emissions. The focus should be on deep decarbonization (to at least 90% by 2050) rather than offsets for it to be a sustainable solution.

  • Planetary boundaries

    Planetary boundaries are a set of nine systems developed by Stockholm Resilience Centre within which humans can continue to develop and thrive. These include: stratospheric ozone depletion, biodiversity loss and extinctions, chemical pollution, climate change, ocean acidification, freshwater consumption and the global hydrological cycle, land system change, nitrogen and phosphorus flows to the biosphere and oceans, and atmospheric aerosol loading. Crossing these boundaries increases the risk of generating large-scale abrupt or irreversible environmental changes.

    Reference: Stockholm Resilience Centre

  • Tipping points

    Tipping points are critical thresholds in a situation, process or system at which a tiny perturbation can dramatically alter the state or development of a system, which can result in an unstoppable effect or change that takes place which can be overall positive or negative?

  • UNFCCC - Paris Agreements on Climate Change

    "The Paris Agreement is a legally binding international treaty on climate change. It was adopted by 196 Parties at the UN Climate Change Conference (COP21) in Paris, France, on 12 December 2015. It entered into force on 4 November 2016. Its overarching goal is to hold “the increase in the global average temperature to well below 2°C above pre-industrial levels” and pursue efforts “to limit the temperature increase to 1.5°C above pre-industrial levels". To limit global warming to 1.5°C, greenhouse gas emissions must peak before 2025 at the latest and decline 43% by 2030."

    Reference: United Nations Climate Change – UNFCCC


    The Conference of the Parties is "the supreme decision-making body of the of the United Nations Framework Convention on Climate Change (UNFCCC). All States that are Parties to the Convention are represented at the COP, at which they review the implementation of the Convention and any other legal instruments that the COP adopts and take decisions necessary to promote the effective implementation of the Convention, including institutional and administrative arrangements.The COP meets every year, unless the Parties decide otherwise. The first COP meeting was held in Berlin, Germany in March, 1995."

    Reference: United Nations Climate Change – UNFCCC

Health, equity, and wellbeing

This theme includes vocabulary related to enviromental and social health drivers, health vulnerability, health equity, and the social determinants of health.

  • Climate preparedness plan

    Climate preparedness plan means having the necessary policies, infrastructure, relationships, and behaviours in place to prepare for, adapt to and recover from events and build resilience to climate impacts.

  • Climate resilience

    Communities are in the frontline of climate change and experience the effects differently depending on their location, situation and health. These are affecting people and communities unequally. As such different and tailored support systems are needed to respond to the impacts of climate change and build resilience for the future. The Geneva Sustainability Centre believes it is part of our healthcare leadership responsibility to recognise different individual and collective needs and to deliver care in such a way as to remove obstacles, build social value and by considering these differences in other frameworks such as pandemic or extreme event preparedness and adaptation to climate change.

  • Climate-resilient care

    Climate-resilient care pathways are clinical care processes for "managing change within complex systems in order to reduce disruptions and enhance opportunities associated with climate change".

    Reference: International Panel on Climate Change – IPCC

  • Climate risks assessment

    Climate risk assessments help identify the likelihood of future climate hazards and the potential impacts they may have for individuals, organizations, cities and communities. These assessments help inform the prioritization of climate action and investment in adaptation.

  • Co-benefits

    Co-benefits are the extra positive effects of a policy or measure which contributes to other policy objectives, usually by increasing overall benefits for society or the environment.

  • Environmental justice

    Environmental justice refers to the fair treatment and meaningful involvement of all people regardless of race, national origin, or income with respect to the development, implementation and enforcement of environmental laws, regulations and policies.

    Reference: United States Environmental Protection Agency – US EPA

  • Equity

    The term "equity" is linked to the concepts of fairness and justice for all. "Equity" differs from "equality" in that it recognizes that not everyone live in the same conditions or has the same access to opportunities.

  • Equitable healthcare

    Equitable healthcare means delivering healthcare in the fairest way possible. This means considering the consequences, outcomes, costs and benefits of actions and policies for different people, places and countries, and actively reducing the burdens and enhancing the benefits to provide healthcare for all.

  • Equity - in relation to climate change

    According to IPCC, equity is the "principle of fairness in burden sharing and is a basis for understanding how the impacts and responses to climate change, including costs and benefits, are distributed in and by society in more or less equal ways".

    Reference: International Panel on Climate Change – IPCC

  • Health - environmental determinants of health

    Environmental determinants of health (EDH) include various environmental factors which affect and influence human health. These include physical, chemical, and biological factors external to an individual and their related behaviors access. Examples of EDH include clean water and hygiene, housing conditions, air quality, work environment exposure, and exposure to extreme weather conditions.

    Reference: World Health Organization – WHO

  • Social determinants of health

    The World Health Organization (WHO) defines the social determinants of health as "the non-medical factors that influence health outcomes. They are the conditions in which people are born, grow, work, live, and age, and the wider set of forces and systems shaping the conditions of daily life".

    Reference: World Health Organization – WHO

  • Health vulnerabilities

    Health vulnerabilities in a public health context is the “the degree to which a system is susceptible to injury, damage, or harm”. This can be applied to individuals, communities, institutions and/or systems.

    Reference: Centers for Disease Control and Prevention – CDC

  • Health vulnerability assessments

    Health vulnerability assessments can assist health management and authorities to identify and interpret relevent information in order to understand the impact of climate change and other risks on their health systems and communities.

  • Sustainability and sustainable healthcare systems

    Sustainability has many meanings, which are all significant. The most recognized version is from a 1987 UN conference, stating sustainable developments are those that “meet present needs without compromising the ability of future generations to meet their needs”.
    The World Health Organisation (WHO) defines a sustainable healthcare system as "a system that improves, maintains or restores health, while minimizing negative impacts on the environment and leveraging opportunities to restore and improve it, to the benefit of the health and well-being of current and future generations".
    Driving the changes for sustainability required in response to climate change is imperative and needs to be done whilst avoiding unintended consequences on other fragile planetary, health and social systems. This means for instance being very attentive to conserve water; minimise the use of toxic chemicals and products, enhancing our natural environment, and respecting human rights.

    Reference: United Nations – UN

Leadership and governance

This theme includes vocabulary related to governance, ESG, employee engagement and empowerment, and stakeholder collaboration.

  • Carbon budget

    The carbon budget is the maximum amount of carbon that can be emitted by an organization or entity over a period of time based on its carbon emission reduction goals. Carbon budgets can be set by individuals, organizations (including companies) and countries and should be based on science-based targets.

  • ESG

    ESG stands for environmental, social, and governance – a framework for examining organizations in the context of impact and/or risk in these areas. As defined by rating agencies (e.g. MSCI), ESG focuses more broadly on financial risks to an organization.

  • Science-based targets and related initiatives

    "Emissions reductions targets adopted by companies to reduce greenhouse gas emissions are considered 'science-based' if they are in line with the level of decarbonization required to keep global temperature increase below 2°C compared to pre-industrial temperatures, as described by the Intergovernmental Panel on Climate Change (IPCC)."

    The science-based targets initiative provides resources (guidance documents, webinars) to help businesses set science-based targets for reducing greenhouse gas emissions. Operated as a partnership between CDP, the United Nations Global Compact, World Resources Institute (WRI) and the World Wide Fund for Nature (WWF). The goal is to reach the target set by the 2015 Paris Agreements and limit global warming to 1.5°C.

    Reference: Science Based Targets

  • Sustainable Development Goals

    Generated by the UN, the 17 Sustainable Development Goals are the blueprint and call for action to end poverty and other deprivations, by implementing strategies to improve health, education, and economic growth, while also reducing inequality and tackling climate change and preserving biodiversity, forests and oceans. They were adopted by all Member States in 2015.

    Reference: United Nations – UN

  • Chief Sustainability Officer

    Chief Sustainability Officer is an executive who leads and manages an organization's strategy and practices to ensure they are environmentally, socially and economically sustainable.

    Reference: Harvard Business Review – HBR