Andy Reisinger (New Zealand), Diego Cammarano (Italy), Andreas Fischlin (Switzerland), Jan S. Fuglestvedt (Norway), Gerrit Hansen (Germany), Yonghun Jung (Republic of Korea), Chloé Ludden (Germany/France), Valérie Masson-Delmotte (France), J.B. Robin Matthews (France/United Kingdom), Katja Mintenbeck (Germany), Dan Jezreel Orendain (Philippines/Belgium), Anna Pirani (Italy), Elvira Poloczanska (UK/Australia), José Romero (Switzerland)

This Annex should be cited as: IPCC, 2023: Annex I: Glossary [Reisinger, A., D. Cammarano, A. Fischlin, J.S. Fuglestvedt, G. Hansen, Y. Jung, C. Ludden, V. Masson-Delmotte, R. Matthews, J.B.K Mintenbeck, D.J. Orendain, A. Pirani, E. Poloczanska, and J. Romero (eds.)]. In: Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change[Core Writing Team, H. Lee and J. Romero (eds.)]. IPCC, Geneva, Switzerland, pp. 119-130, doi:10.59327/IPCC/AR6-9789291691647.002.

This concise Synthesis Report (SYR) Glossary defines selected key terms used in this report, drawn from the glossaries of the three Working Groupcontributions to the AR6. A more comprehensive, harmonised set of definitions for terms used in this SYR and the three AR6 Working Group reports is available from the IPCC Online Glossary: https://apps.ipcc.ch/glossary/

Readers are requested to refer to this comprehensive online glossary for definitions of terms of a more technical nature, and for scientific references relevant to individual terms. Italicized words indicate that the term is defined in this or/and the online glossary. Subterms appear in italics beneath main terms.

2030 Agenda for Sustainable Development

A UN resolution in September 2015 aadopting a plan of action for people, planet and prosperity in a new global development framework anchored in 17Sustainable Development Goals.

Abrupt climate change

A large-scale abrupt change in the climate system that takes place over a few decades or less, persists (or is anticipated to persist) for at least a few decades and causes substantial impacts in human and/or natural systems. See also: Abrupt change, Tipping point .

Adaptation

In human systems, the process of adjustment to actual or expected climate and its effects, in order to moderate harm or exploit beneficial opportunities. In natural systems, the process of adjustment to actual climate and its effects; human intervention may facilitate adjustment to expected climate and its effects. See also: Adaptationoptions, Adaptive capacity, Maladaptive actions (Maladaptation) .

Adaptation gap

The difference between actually implemented adaptation and a societally set goal, determined largely by preferences related to tolerated climate change impacts and reflecting resource limitations and competing priorities.

Adaptationlimits

The point at which an actor’s objectives (or system needs) cannot be secured from intolerable risks through adaptive actions.

• Hard adaptation.limit - No adaptive actions are possible to avoid intolerable risks.
• Soft adaptation limit - Options may exist but are currently not available to avoid intolerable risks through adaptive action.

Transformational adaptation

Adaptation that changes the fundamental attributes of a social-ecological system in anticipation of climate change and its impacts.

Aerosol

A suspension of airborne solid or liquid particles, with typical particle size in the range of a few nanometres to several tens of micrometres and atmospheric lifetimes of up to several days in the troposphere and up to years in the stratosphere. The term aerosol, which includes both the particles and the suspending gas, is often used in this report in its plural form to mean ‘aerosol particles’. Aerosols may be of either natural or anthropogenic origin in the troposphere; stratospheric aerosols mostly stem from volcanic eruptions. Aerosols can cause an effectiveradiative forcing directly through scattering and absorbing radiation . aerosol–radiation interaction) , and indirectly by acting as cloud condensation nuclei or ice nucleating particles that affect the properties of clouds (aerosol–cloud interaction) , and upon deposition on snow- or ice-covered surfaces. Atmospheric aerosols may be either emitted as primary particulate matter or formed within the atmosphere from gaseous precursors (secondary production). Aerosols may be composed of sea salt, organic carbon, black carbon (BC), mineral species (mainly desert dust), sulphate, nitrate and ammonium or their mixtures. See also: Particulate matter (PM) , Aerosol–radiation interaction, Short-livedclimate forcers (SLCFs) .

Afforestation

Conversion to forest of land that historically has not contained forests. See also: Anthropogenic removals, Carbon dioxide removal (CDR) , Deforestation, Reducing Emissions fromDeforestation and Forest Degradation (REDD+) , Reforestation.

[Note: For a discussion of the term forest and related terms such as afforestation, reforestation and deforestation, see the 2006 IPCC Guidelines for National Greenhouse Gas Inventories and their 2019 Refinement, and information provided by the United Nations Framework Convention on Climate Change]

Agricultural drought

See: Drought .

Agriculture, Forestry and Other Land Use ( AFOLU)

In the context of national greenhouse gas (GHG) inventories under the United Nations Convention on Climate Change (UNFCCC) , AFOLU is the sum of the GHG inventory sectors Agriculture and Land Use, Land-Use Change and Forestry (LULUCF) ; see the 2006 IPCC Guidelines for National GHG Inventories for details. Given the difference in estimating the ‘anthropogenic’ carbon dioxide (CO2) removals between countries and the global modelling community, the land-related net GHG emissions from global models included in this report are not necessarily directly comparable with LULUCF estimates in national GHG Inventories. See also: Land use, land-use change and forestry (LULUCF) , Land-use change (LUC) .

Agroforestry

Collective name for land-use systems and technologies where woody perennials (trees, shrubs, palms, bamboos, etc.) are deliberately used on the same land-management units as agricultural crops and/or animals, in some form of spatial arrangement or temporal sequence. In agroforestry systems there are both ecological and economical interactions between the different components. Agroforestry can also be defined as a dynamic, ecologically based, natural resource management system that, through the integration of trees on farms and in the agricultural landscape, diversifies and sustains production for increased social, economic and environmental benefits for land users at all levels.

Anthropogenic

Resulting from or produced by human activities.

Behavioural change

In this report, behavioural change refers to alteration of human decisions and actions in ways that mitigate climate change and/or reduce negative consequences of climate change impacts.

Biodiversity

Biodiversity or biological diversity means the variability among living organisms from all sources including, among other things, terrestrial, marine and other aquatic ecosystems, and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems. See also: Ecosystem, Ecosystem services.

Bioenergy

Energy derived from any form of biomass or its metabolic by-products. See also: Biofuel.

Bioenergy with carbon dioxide capture and storage (BECCS)

Carbon dioxide capture and storage (CCS). technology applied to a bioenergy facility. Note that, depending on the total emissions of the BECCS supply chain, carbon dioxide (CO2) can be removed from the atmosphere. See also: Anthropogenic removals, Carbon dioxide capture and storage (CCS) , Carbon dioxide removal (CDR).

Blue carbon

Biologically-driven carbon fluxes and storage in marine systems that are amenable to management. Coastal blue carbon focuses on rooted vegetation in the coastal zone, such as tidal marshes, mangroves and seagrasses. These ecosystems have high carbon burial rates on a per unit area basis and accumulate carbon in their soils and sediments. They provide many non-climatic benefits and can contribute to ecosystem-basedadaptation. If degraded or lost, coastal blue carbon ecosystems are likely to release most of their carbon back to the atmosphere. There is current debate regarding the application of the blue carbon concept to other coastal and non-coastal processes and ecosystems, including the open ocean. See also: Ecosystem services, Sequestration.

Blue infrastructure

See: Infrastructure.

Carbon budget

Refers to two concepts in the literature:

(1) an assessment of carbon cycle sources and sinks on a global level, through the synthesis of evidence for fossil fuel and cement emissions, emissions and removals associated with land use and land-use change, ocean and natural land sources and sinks of carbon dioxide (CO2) , and the resulting change in atmospheric CO2 concentration. This is referred to as the Global Carbon Budget; (2) the maximum amount of cumulative net global anthropogenicCO2 emissions that would result in limiting global warming to a given level with a given probability, taking into account the effect of other anthropogenic climate forcers. This is referred to as the Total Carbon Budget when expressed starting from the pre-industrial period, and as the Remaining Carbon Budget when expressed from a recent specified date.

[Note 1: Net anthropogenic CO2 emissions are anthropogenicCO2 emissions minus anthropogenicCO2 removals. See also: Carbon Dioxide Removal (CDR) .

Note 2: The maximum amount of cumulative net global anthropogenicCO2 emissions is reached at the time that annual net anthropogenic.CO2 emissions reach zero.

Note 3: The degree to which anthropogenic climate forcers other than CO2 affect the total carbon budget and remaining carbon budget depends on human choices about the extent to which these forcers are mitigated and their resulting climate effects.

Note 4: The notions of a total carbon budget and remaining carbon budget are also being applied in parts of the scientific literature and by some entities at regional, national, or sub-national level. The distribution of global budgets across individual different entities and emitters depends strongly on considerations of equity and other value judgements.]

Carbon dioxide capture and storage (CCS)

A process in which a relatively pure stream of carbon dioxide (CO2).from industrial and energy-related sources is separated (captured), conditioned, compressed and transported to a storage location for long-term isolation from the atmosphere. Sometimes referred to as Carbon Capture and Storage. See also: Anthropogenic removals, Bioenergy with carbon dioxide capture and storage (BECCS) , Carbon dioxide capture and utilisation (CCU) , Carbon dioxide removal (CDR) , Sequestration.

Carbon dioxide removal (CDR)

Anthropogenic activities removing carbon dioxide (CO2) from the atmosphere and durably storing it in geological, terrestrial, or ocean reservoirs, or in products. It includes existing and potential anthropogenic enhancement of biological or geochemical CO2sinks and direct air carbon dioxide capture and storage (DACCS) but excludes natural CO2uptake not directly caused by human activities. See also: Afforestation, Anthropogenic removals, Biochar, Bioenergy with carbon dioxide capture and storage (BECCS) , Carbon dioxide capture and storage (CCS) , Enhanced weathering, Ocean alkalinization/Ocean alkalinity enhancement , Reforestation, Soilcarbon sequestration (SCS).

Cascading impacts

Cascading impacts from extreme weather/climate events occur.when an extreme hazard generates a sequence of secondary events in natural and human systems that result in physical, natural, social or economic disruption, whereby the resulting impact is significantly larger than the initial impact. Cascading impacts are complex and multi-dimensional, and are associated more with the magnitude of vulnerability than with that of the hazard.

Climate

In a narrow sense, climate is usually defined as the average weather -or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities- over a period of time ranging from months to thousands or millions of years. The classical period for averaging these variables is 30 years, as defined by the World Meteorological Organization (WMO). The relevant quantities are most often surface variables such as temperature, precipitation and wind. Climate in a wider sense is the state, including a statistical description, of the climate system.

Climate change

A change in the state of the climate that can be identified (e.g., by 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. Climate change may be due to natural internal processes or external forcings such as modulations of the solar cycles, volcanic eruptions and persistent anthropogenic changes in the composition of the atmosphere or in land use. See also: Climate variability, Detection andattribution, Global warming, Natural (climate) variability, Oceanacidification (OA).

[Note that the United Nations Framework Convention on Climate Change (UNFCCC), in its Article 1, defines climate change as: ‘a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to naturalclimate variability observed over comparable time periods’. The UNFCCC thus makes a distinction between climate change attributable to human activities altering the atmospheric composition and climate variability attributable to natural causes.]

Climate extreme (extreme weather or climate event)

The occurrence of a value of a weather or climate variable above (or below) a threshold value near the upper (or lower) ends of the range of observed values of the variable. By definition, the characteristics of what is called extreme weather may vary from place to place in an absolute sense. When a pattern of extreme weather persists for some time, such as a season, it may be classified as an extreme climate event, especially if it yields an average or total that is itself extreme (e.g., high temperature, drought , or heavy rainfall over a season). For simplicity, both extreme weather events and extreme climate events are referred to collectively as ‘climate extremes’.

Climate finance

There is no agreed definition of climate finance. The term ‘climate finance’ is applied to the financial resources devoted to addressing climate change by all public and private actors from global to local scales, including international financial flows to developing countries to assist them in addressing climate change. Climate finance aims to reduce net greenhouse gas emissions and/or to enhance adaptation and increase resilience to the impacts of current and projected climate change. Finance can come from private and public sources, channelled by various intermediaries, and is delivered by a range of instruments, including grants, concessional and non-concessional debt, and internal budget reallocations.

Climate governance

The structures, processes, and actions through which private and public actors seek to mitigate and adapt to climate change .

Climate justice

See: Justice.

Climate literacy

Climate literacy encompasses being aware of climate change, its anthropogenic causes, and implications.

Climate resilient development (CRD)

Climate-resilient development refers to the process of implementing greenhouse gasmitigation and adaptation measures to support sustainable development .for all.

Climate sensitivity

The change in the surface temperature in response to a change in the atmospheric carbon dioxide (CO2) concentration or other radiative forcing. See also: Climate feedback parameter.

Equilibriumclimate sensitivity (ECS)

The equilibrium (steady state) change in the surface temperature following a doubling of the atmospheric carbon dioxide (CO2) concentration from pre-industrial.conditions.

Climate services

Climate services involve the provision of climate information in such a way as to assist decision-making. The service includes appropriate engagement from users and providers, is based on scientifically credible information and expertise, has an effective access mechanism, and responds to user needs.

Climate system

The global system consisting of five major components: the atmosphere, the hydrosphere, the cryosphere, the lithosphere and the biosphere, and the interactions between them. The climate system changes in time under the influence of its own internal dynamics and because of externalforcings such as volcanic eruptions, solar variations, orbital forcing, and anthropogenic forcings such as the changing composition of the atmosphere and. land-use change.

Climatic impact-driver (CID)

Physical climate system conditions (e.g., means, events, extremes) that affect an element of society or ecosystems. Depending on system tolerance, CIDs and their changes can be detrimental, beneficial, neutral or a mixture of each across interacting system elements and regions. See also: Hazard, Impacts, Risk.

CO2 -equivalent emission (CO2 -eq)

The amount of carbon dioxide (CO2) emission that would have an equivalent effect on a specified key measure of climate change, over a specified time horizon, as an emitted amount of another greenhouse gas (GHG) or a mixture of other GHGs. For a mix of GHGs it is obtained by summing the CO2-equivalent emissions of each gas. There are various ways and time horizons to compute such equivalent emissions (see greenhouse gas emission metric). CO2-equivalent emissions are commonly used to compare emissions of different GHGs but should not be taken to imply that these emissions have an equivalent effect across all key measures of climate change.

[Note: Under the Paris Rulebook [Decision 18/CMA.1, annex, paragraph 37], parties have agreed to use GWP100 values from the IPCC AR5 or GWP100 values from a subsequent IPCC Assessment Report to report aggregate emissions and removals of GHGs. In addition, parties may use other metrics to report supplemental information on aggregate emissions and removals of GHGs.]

Compound weather/ climate events

The terms ‘compound events’, ‘compound extremes’ and ‘compound extreme events’ are used interchangeably in the literature and this report, and refer to the combination of multiple drivers and/or hazards that contribute to societal and/or environmental risk.

Deforestation

Conversion of forest to non-forest. See also: Afforestation, Reforestation, Reducing Emissions fromDeforestation and Forest Degradation (REDD+).

[Note: For a discussion of the term forest and related terms such as afforestation, reforestation and deforestation, see the 2006 IPCC Guidelines for National Greenhouse Gas Inventories and their 2019 Refinement, and information provided by the United Nations Framework Convention on Climate Change]

Demand-side measures

Policies and programmes for influencing the demand for goods and/ or services. In the energy sector, demand-side mitigation measures aim at reducing the amount of greenhouse gas emissions emitted per unit of energy service used.

Developed / developing countries (Industrialissed / developed / developing countries)

There is a diversity of approaches for categorizing countries on the basis of their level of development, and for defining terms such as industrialised, developed, or developing. Several categorisations are used in this report. (1) In the United Nations (UN) system, there is no established convention for the designation of developed and developing countries or areas. (2) The UN Statistics Division specifies developed and developing regions based on common practice. In addition, specific countries are designated as least developed countries, landlocked developing countries, Small Island Developing States (SIDS) , and transition economies. Many countries appear in more than one of these categories. (3) The World Bank uses income as the main criterion for classifying countries as low, lower middle, upper middle, and high income. (4) The UN Development Programme (UNDP) aggregates indicators for life expectancy, educational attainment, and income into a single composite Human Development Index (HDI) to classify countries as low, medium, high, or very high human development.

Development pathways

See: Pathways.

Disaster risk management (DRM)

Processes for designing, implementing and evaluating strategies, policies and measures to improve the understanding of current and future disasterrisk, foster disasterrisk reduction and transfer, and promote continuous improvement in disaster preparedness, prevention and protection, response and recovery practices, with the explicit purpose of increasing humansecurity, well-being, quality of life and sustainable development (SD).

Displacement ( of humans)

The involuntary movement, individually or collectively, of persons from their country or community, notably for reasons of armed conflict, civil unrest, or natural or human-made disasters.

Drought

An exceptional period of water shortage for existing ecosystems and the human population (due to low rainfall, high temperature and/or wind). See also: Plant evaporative stress.

Agricultural and ecologicaldrought

Depending on the affected biome: a period with abnormal soil moisture deficit, which results from combined shortage of precipitation and excess evapotranspiration, and during the growing season impinges on crop production or ecosystem function in general.

Early warning systems (EWS)

The set of technical and institutional capacities to forecast, predict, and communicate timely and meaningful warning information to enable individuals, communities, managed ecosystems, and organisations threatened by a hazard to prepare to act promptly and appropriately to reduce the possibility of harm or loss. Depending upon context, EWS may draw upon scientific and/or Indigenous knowledge, and other knowledge types. EWS are also considered for ecological applications, e.g., conservation, where the organisation itself is not threatened by hazard but the ecosystem.under conservation is (e.g., coral bleaching alerts), in agriculture (e.g., warnings of heavy rainfall, drought , ground frost, and hailstorms) and in fisheries (e.g., warnings of storm, storm surge, and tsunamis).

Ecological drought

See: Drought .

Ecosystem

An ecosystem is a functional unit consisting of living organisms, their nonliving environment and the interactions within and between them. The components included in a given ecosystem and its spatial boundaries depend on the purpose for which the ecosystem is defined: in some cases, they are relatively sharp, while in others they are diffuse. Ecosystem boundaries can change over time. Ecosystems are nested within other ecosystems and their scale can range from very small to the entire biosphere. In the current era, most ecosystems either contain people as key organisms, or are influenced by the effects of human activities in their environment. See also: Ecosystem health, Ecosystem services.

Ecosystem-basedadaptation (EbA)

The use of ecosystem management activities to increase the resilience and reduce the vulnerability of people and ecosystems to climate change. See also: . Adaptation, Nature-based solution (NbS).

Ecosystem services

Ecological processes or functions having monetary or non-monetary value to individuals or society at large. These are frequently classified as (1) supporting services such as productivity or biodiversity maintenance, (2) provisioning services such as food or fibre, (3) regulating services such as climate regulation or carbon sequestration, and (4) cultural services such as tourism or spiritual and aesthetic appreciation. See also: Ecosystem, Ecosystem health, Nature’scontributions to people (NCP).

Emission scenario

See: Scenario.

Emission pathways

See: Pathways.

Enabling conditions (for adaptation and mitigation options)

Conditions that enhance the feasibility of adaptation and mitigation options. Enabling conditions include finance, technological innovation, strengthening policy instruments, institutional capacity, multi-levelgovernance, and changes in human behaviour and lifestyles.

Equality

A principle that ascribes equal worth to all human beings, including equal opportunities, rights and obligations, irrespective of origins. See also: Equity, Fairness.

Inequality

Uneven opportunities and social positions, and processes of discrimination within a group or society, based on gender, class, ethnicity, age, and (dis)ability, often produced by uneven development. Income inequality refers to gaps between highest and lowest income earners within a country and between countries.

Equilibrium climate sensitivity (ECS)

See: Climate sensitivity.

Equity

The principle of being fair and impartial, and 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. Often aligned with ideas of equality, fairness and justice and applied with respect to equity in the responsibility for, and distribution of, climate impacts and policies across society, generations, and gender, and in the sense of who participates and controls the processes of decision-making.

Exposure

The presence of people; livelihoods; species or ecosystems; environmental functions, services, and resources; infrastructure; or economic, social, or cultural assets in places and settings that could be adversely affected. See also: Hazard, Exposure, Vulnerability, Impacts, Risk.

Feasibility

In this report, feasibility refers to the potential for a mitigation or adaptation option to be implemented. Factors influencing feasibility are context-dependent, temporally dynamic, and may vary between different groups and actors. Feasibility depends on geophysical, environmental-ecological, technological, economic, socio-cultural and institutional factors that enable or constrain the implementation of an option. The feasibility of options may change when different options are combined and increase when enabling conditions.are strengthened.. See also: Enabling conditions (foradaptation andmitigationoptions) .

Fire weather

Weather conditions conducive to triggering and sustaining wildfires, usually based on a set of indicators and combinations of indicators including temperature, soil moisture, humidity, and wind. Fire weather does not include the presence or absence of fuel load.

Food loss and waste

The decrease in quantity or quality of food. Food waste is part of food loss and refers to discarding or alternative (non-food) use of food that is safe and nutritious for human consumption along the entire food supply chain, from primary production to end household consumer level. Food waste is recognized as a distinct part of food loss because the drivers that generate it and the solutions to it are different from those of food losses.

Food security

A situation that exists when all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life. The four pillars of food security are availability, access, utilization and stability. The nutritional dimension is integral to the concept of food security.

Global warming

Global warming refers to the increase in global surface temperature relative to a baseline reference period, averaging over a period sufficient to remove interannual variations (e.g., 20 or 30 years). A common choice for the baseline is 1850–1900 (the earliest period of reliable observations with sufficient geographic coverage), with more modern baselines used depending upon the application. See also: Climate change, Climate variability, Natural (climate) variability.

Global warming potential (GWP)

An index measuring the radiative forcing following an emission of a unit mass of a given substance, accumulated over a chosen time horizon, relative to that of the reference substance, carbon dioxide (CO2). The GWP thus represents the combined effect of the differing times these substances remain in the atmosphere and their effectiveness in causing radiative forcing. See also: Lifetime, Greenhouse gas emission metric.

Green infrastructure

See: Infrastructure.

Greenhouse gases (GHGs)

Gaseous constituents of the atmosphere, both natural and anthropogenic, that absorb and emit radiation at specific wavelengths within the spectrum of radiation emitted by the Earth’s surface, by the atmosphere itself, and by clouds. This property causes the greenhouse effect . Water vapour (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4) and ozone (O3) are the primary GHGs in the Earth’s atmosphere. Human-made GHGs include sulphur hexafluoride (SF6), hydrofluorocarbons (HFCs), chlorofluorocarbons (CFCs) and perfluorocarbons (PFCs); several of these are also O3-depleting (and are regulated under the Montreal Protocol). See also: Well-mixed greenhouse gas.

Grey infrastructure

See: Infrastructure.

Hazard

The potential occurrence of a natural or human-induced physical event or trend that may cause loss of life, injury or other health impacts, as well as damage and loss to property, infrastructure, livelihoods, service provision, ecosystems and environmental resources. See also: Exposure, Vulnerability, Impacts, Risk.

Impacts

The consequences of realised risks on natural and human systems, where risks result from the interactions of climate-related hazards (including extreme weather/climate events), exposure, andvulnerability. Impacts generally refer to effects on lives, livelihoods, health and well-being, ecosystems and species, economic, social and cultural assets, services (including ecosystem services), and infrastructure. Impacts may be referred to as consequences or outcomes and can be adverse or beneficial. See also: Adaptation, Hazard, Exposure, Vulnerability, Risk.

Inequality

See: Equality.

Indigenous knowledge (IK)

The understandings, skills and philosophies developed by societies with long histories of interaction with their natural surroundings. For many Indigenous Peoples, IK informs decision-making about fundamental aspects of life, from day-to-day activities to longer term actions. This knowledge is integral to cultural complexes, which also encompass language, systems of classification, resource use practices, social interactions, values, ritual and spirituality. These distinctive ways of knowing are important facets of the world’s cultural diversity. See also: Local knowledge (LK) .

Indigenous Peoples

Indigenous Peoples and nations are those that, having a historical continuity with pre-invasion and pre-colonial societies that developed on their territories, consider themselves distinct from other sectors of the societies now prevailing on those territories, or parts of them. They form at present principally non-dominant sectors of society and are often determined to preserve, develop, and transmit to future generations their ancestral territories, and their ethnic identity, as the basis of their continued existence as peoples, in accordance with their own cultural patterns, social institutions, and common law system.

Informal settlement

A term given to settlements or residential areas that by at least one criterion fall outside official rules and regulations. Most informal settlements have poor housing (with widespread use of temporary materials) and are developed on land that is occupied illegally with high levels of overcrowding. In most such settlements, provision for safe water, sanitation, drainage, paved roads, and basic services is inadequate or lacking. The term ‘slum’ is often used for informal settlements, although it is misleading as many informal settlements develop into good quality residential areas, especially where governments support such development.

Infrastructure

The designed and built set of physical systems and corresponding institutional arrangements that mediate between people, their communities, and the broader environment to provide services that support economic growth, health, quality of life, and safety.

Blueinfrastructure

Blue infrastructure includes bodies of water, watercourses, ponds, lakes and storm drainage, that provide ecological and hydrological functions including evaporation, transpiration, drainage, infiltration, and temporary storage of runoff and discharge.

Greeninfrastructure

The strategically planned interconnected set of natural and constructed ecological systems, green spaces and other landscape features that can provide functions and services including air and water purification, temperature management, floodwater management and coastal defence often with co-benefits for people and biodiversity. Green infrastructure includes planted and remnant native vegetation, soils, wetlands, parks and green open spaces, as well as building and street level design interventions that incorporate vegetation.

Greyinfrastructure

Engineered physical components and networks of pipes, wires, tracks and roads that underpin energy, transport, communications (including digital), built form, water and sanitation, and solid-waste management systems.

Irreversibility

A perturbed state of a dynamical system is defined as irreversible on a given time scale if the recovery from this state due to natural processes takes substantially longer than the time scale of interest. See also: Tipping point .

Just transition

See: Transition.

Justice

Justice is concerned with ensuring that people get what is due to them, setting out the moral or legal principles of fairness and equity in the way people are treated, often based on the ethics and values of society.

Climatejustice

Justice that links development and human rights to achieve a human-centred approach to addressing climate change, safeguarding the rights of the most vulnerable people and sharing the burdens and benefits of climate change and its impacts equitably and fairly.

Socialjustice

Just or fair relations within society that seek to address the distribution of wealth, access to resources, opportunity, and support according to principles of justice and fairness.

Key risk

See: Risk.

Land use, land-use change and forestry (LULUCF)

In the context of national greenhouse gas (GHG) inventories under the United Nations Framework Convention on Climate Change, LULUCF is a GHG inventory sector that covers anthropogenicemissions and removals of GHG in managed lands, excluding non-CO2 agricultural emissions. Following the 2006 IPCC Guidelines for National GHG Inventories and their 2019 Refinement, . anthropogenic. land-related GHG fluxes are defined as all those occurring on . managed land., i.e., ‘where human interventions and practices have been applied to perform production, ecological or social functions’. Since managed land may include carbon dioxide (CO2) removals not considered as ‘anthropogenic’ in some of the scientific literature assessed in this report (e.g., removals associated with CO2 fertilisation and N deposition), the land-related net GHG emission estimates from global models included in this report are not necessarily directly comparable with LULUCF estimates in National GHG Inventories (IPCC 2006, 2019).

Least Developed Countries (LDCs)

A list of countries designated by the Economic and Social Council of the United Nations (ECOSOC) as meeting three criteria: (1) a low income criterion below a certain threshold of gross national income per capita of between USD 750 and USD 900, (2) a human resource weakness based on indicators of health, education, adult literacy, and (3) an economic vulnerability weakness based on indicators on instability of agricultural production, instability of export of goods and services, economic importance of non-traditional activities, merchandise export concentration, and the handicap of economic smallness. Countries in this category are eligible for a number of programmes focused on assisting countries most in need. These privileges include certain benefits under the articles of the United Nations Framework Convention on Climate Change (UNFCCC).

Livelihood

The resources used and the activities undertaken in order for people to live. Livelihoods are usually determined by the entitlements and assets to which people have access. Such assets can be categorised as human, social, natural, physical or financial.

Local knowledge (LK)

The understandings and skills developed by individuals and populations, specific to the places where they live. Local knowledge informs decision-making about fundamental aspects of life, from day-to-day activities to longer term actions. This knowledge is a key element of the social and cultural systems which influence observations of and responses to climate change; it also informs governance decisions. See also: Indigenous knowledge (IK) .

Lock-in

A situation in which the future development of a system, including infrastructure, technologies, investments, institutions, and behavioural norms, is determined or constrained (‘locked in’) by historic developments. See also: Path dependence.

Loss and Damage, and losses and damages

Research has taken Loss and Damage (capitalised letters) to refer to political debate under the United Nations Framework Convention on Climate Change (UNFCCC) following the establishment of the Warsaw Mechanism on Loss and Damage in 2013, which is to ‘address loss and damage associated with impacts of climate change, including extreme events and slow onset events, in developing countries that are particularly vulnerable to the adverse effects of climate change.’ Lowercase letters (losses and damages) have been taken to refer broadly to harm from (observed)impacts and (projected) risks and can be economic or non-economic.

Low- likelihood, high-impact outcomes

Outcomes/events whose probability of occurrence is low or not well known (as in the context of deepuncertainty) but whose potential impacts on society and ecosystems could be high. To better inform risk assessment and decision-making, such low-likelihood outcomes are considered if they are associated with very large consequences and may therefore constitute material risks, even though those consequences do not necessarily represent the most likely outcome. See also: Impacts.

Maladaptive actions ( Maladaptation)

Actions that may lead to increased risk of adverse climate-related outcomes, including via increased greenhouse gas (GHG) emissions, increased or shifted vulnerability to climate change, more inequitable outcomes, or diminished welfare, now or in the future. Most often, maladaptation is an unintended consequence.

Migration ( of humans)

Movement of a person or a group of persons, either across an international border, or within a State. It is a population movement, encompassing any kind of movement of people, whatever its length, composition and causes; it includes migration of refugees, displaced persons, economic migrants, and persons moving for other purposes, including family reunification.

Mitigation ( of climate change)

A human intervention to reduce emissions or enhance the sinksof greenhouse gases.

Mitigation potential

The quantity of net greenhouse gas emission reductions that can be achieved by a given mitigation option relative to specified emission baselines. See also: Sequestrationpotential.

[Note: Net greenhouse gas emission reductions is the sum of reduced emissions and/or enhanced sinks]

Natural ( climate) variability

Natural variability refers to climatic fluctuations that occur without any human influence, that is. internal variability.combined with the response to external natural factors such as volcanic eruptions, changes in solar activity and, on longer time-scales, orbital effects and plate tectonics. See also: Orbital forcing.

Net zero CO2 emissions

Condition in which anthropogenic carbon dioxide (CO2) emissions are balanced by anthropogenic CO2removals over a specified period. See also: Carbon neutrality, Land use, land-use change and forestry (LULUCF) , Net zero greenhouse gasemissions.

[Note: Carbon neutrality and net zero CO2 emissions are overlapping concepts. The concepts can be applied at global or sub-global scales (e.g., regional, national and sub-national). At a global scale, the terms carbon neutrality and net zero CO2 emissions are equivalent. At sub-global scales, net zero CO2 emissions is generally applied to emissions and removals under direct control or territorial responsibility of the reporting entity, while carbon neutrality generally includes emissions and removals within and beyond the direct control or territorial responsibility of the reporting entity. Accounting rules specified by GHG programmes or schemes can have a significant influence on the quantification of relevant CO2 emissions and removals.]

Net zero GHG emissions

Condition in which metric-weighted anthropogenic greenhouse gas (GHG) emissions are balanced by metric-weighted anthropogenicGHG removals over a specified period. The quantification of net zero GHG emissions depends on the GHG emission metric chosen to compare emissions and removals of different gases, as well as the time horizon chosen for that metric. See also: Greenhouse gas neutrality, Land use, land-use change and forestry (LULUCF) , Net zero CO2emissions.

[Note 1: Greenhouse gas neutrality and net zero GHG emissions are overlapping concepts. The concept of net zero GHG emissions can be applied at global or sub-global scales (e.g., regional, national and sub-national). At a global scale, the terms GHG neutrality and net zero GHG emissions are equivalent. At sub-global scales, net zero GHG emissions is generally applied to emissions and removals under direct control or territorial responsibility of the reporting entity, while GHG neutrality generally includes anthropogenic emissions and anthropogenic removals within and beyond the direct control or territorial responsibility of the reporting entity. Accounting rules specified by GHG programmes or schemes can have a significant influence on the quantification of relevant emissions and removals.

Note 2: Under the Paris Rulebook (Decision 18/CMA.1, annex, paragraph 37), parties have agreed to use GWP100 values from the IPCC AR5 or GWP100 values from a subsequent IPCC Assessment Report to report aggregate emissions and removals of GHGs. In addition, parties may use other metrics to report supplemental information on aggregate emissions and removals of GHGs.]

New Urban Agenda

The New Urban Agenda was adopted at the United Nations Conference on Housing and Sustainable Urban Development (Habitat III) in Quito, Ecuador, on 20 October 2016. It was endorsed by the United Nations General Assembly at its sixty-eighth plenary meeting of the seventy-first session on 23 December 2016.

Overshoot pathways

See: Pathways.

Pathways

The temporal evolution of natural and/or human systems.towards a future state. Pathway concepts range from sets of quantitative and qualitative scenarios.or narratives.of potential futures to solution-oriented decision-making processes to achieve desirable societal goals. Pathway approaches typically focus on biophysical, techno-economic and/or socio-behavioural trajectories and involve various dynamics, goals and actors across different scales. See also: Scenario, Storyline.

Development pathways

Development pathways evolve as the result of the countless decisions being made and actions being taken at all levels of societal structure, as well due to the emergent dynamics within and between institutions, cultural norms, technological systems and other drivers of behavioural change. See also: Shiftingdevelopment pathways (SDPs) , Shiftingdevelopment pathways to sustainability (SDPS).

Emissionpathways

Modelled trajectories of global anthropogenicemissions over the 21st century are termed emission pathways.

Overshoot pathways

Pathways that first exceed a specified concentration, forcing or global warming level, and then return to or below that level again before the end of a specified period of time (e.g., before 2100). Sometimes the magnitude and likelihood of the overshoot are also characterised. The overshoot duration can vary from one pathway to the next, but in most overshoot pathways in the literature and referred to as overshoot pathways in the AR6, the overshoot occurs over a period of at least one decade and up to several decades. See also: Temperatureovershoot .

Shared socio-economicpathways (SSPs)

Shared socio-economic pathways (SSPs) have been developed to complement the Representative Concentration Pathways (RCPs) . By design, the RCP emission and concentration pathways were stripped of their association with a certain socio-economic development. Different levels of emissions and climate change along the dimension of the RCPs can hence be explored against the backdrop of different socio-economic development pathways (SSPs) on the other dimension in a matrix. This integrative SSP-RCP framework is now widely used in the climate impact and policy analysis literature (see, e.g., http://iconics-ssp.org), where climateprojections obtained under the RCPscenarios are analysed against the backdrop of various SSPs. As several emission updates were due, a new set of emissionscenarios was developed in conjunction with the SSPs. Hence, the abbreviation SSP is now used for two things: On the one hand SSP1, SSP2, …, SSP5 is used to denote the five socio-economic scenario families. On the other hand, the abbreviations SSP1-1.9, SSP1-2.6, …, SSP5-8.5 are used to denote the newly developed emissionscenarios.that are the result of an SSP implementation within an. integrated assessment model. Those SSPscenarios are bare of climate policy assumption, but in combination with so-called shared policy assumptions (SPAs), various approximate radiative forcing levels of 1.9, 2.6, …, or 8.5 W m−2 are reached by the end of the century, respectively. denote trajectories that address social, environmental and economic dimensions of sustainable development , adaptationandmitigation, and transformation, in a generic sense or from a particular methodological perspective such as integrated assessment models.and scenario.simulations.

Planetary health

A concept based on the understanding that human health and human civilisation depend on ecosystem health and the wise stewardship of ecosystems.

Reasons for concern (RFCs)

Elements of a classification framework, first developed in the IPCC Third Assessment Report, which aims to facilitate judgements about what level of climate change may be dangerous (in the language of Article 2 of the UNFCCC; UNFCCC, 1992) by aggregating risks from various sectors, considering hazards, exposures, vulnerabilities, capacities to adapt, and the resulting impacts.

Reforestation

Conversion to forest of land that has previously contained forests but that has been converted to some other use. See also: . Afforestation, Anthropogenic removals, Carbon dioxide removal (CDR) , Deforestation, Reducing Emissions fromDeforestation and Forest Degradation (REDD+) .

[Note: For a discussion of the term forest and related terms such as afforestation, reforestation and deforestation, see the 2006 IPCC Guidelines for National Greenhouse Gas Inventories and their 2019 Refinement, and information provided by the United Nations Framework Convention on Climate Change]

Residual risk

The risk related to climate changeimpacts that remains following adaptation and mitigation efforts. Adaptation actions can redistribute risk and impacts, with increased risk and impact . in some areas or populations, and decreased risk and impacts in others. See also: Loss and Damage, losses and damages.

Resilience

The capacity of interconnected social, economic and ecological systems to cope with a hazardous event, trend or disturbance, responding or reorganizing in ways that maintain their essential function, identity and structure. Resilience is a positive attribute when it maintains capacity for adaptation, learning and/or transformation. See also: Hazard, Risk, Vulnerability.

Restoration

In the environmental context, restoration involves human interventions to assist the recovery of an ecosystem that has been previously degraded, damaged or destroyed.

Risk

The potential for adverse consequences for human or ecological systems, recognising the diversity of values and objectives associated with such systems. In the context of climate change, risks can arise from potential. impacts of climate change as well as human responses to climate change. Relevant adverse consequences include those on lives, livelihoods, health.and well-being, economic, social and cultural assets and investments, infrastructure, services (including ecosystem services), ecosystems.and species.

In the context of climate changeimpacts, risks result from dynamic interactions between climate-related hazards with the exposure and vulnerability of the affected human or ecological system to the hazards. Hazards, exposure and vulnerability may each be subject to uncertainty in terms of magnitude and likelihood.of occurrence, and each may change over time and space due to socio-economic changes and human decision-making.

In the context of climate change responses, risks result from the potential for such responses not achieving the intended objective(s), or from potential trade-offs with, or negative side-effects on, other societal objectives, such as the Sustainable Development Goals (SDGs) . Risks.can arise for example from uncertainty in the implementation, effectiveness or outcomes of climate policy, climate-related investments, technology development or adoption, and system. transitions.

See also: Hazard, Exposure, Vulnerability, Impacts, Riskmanagement, Adaptation, Mitigation.

Keyrisk

Keyrisks have potentially severe adverse consequences for humans and social-ecological systems resulting from the interaction of climate related hazards with vulnerabilities of societies and systems exposed.

Scenario

A plausible description of how the future may develop based on a coherent and internally consistent set of assumptions about key driving forces (e.g., rate of technological change, prices) and relationships. Note that scenarios are neither predictions nor forecasts but are used to provide a view of the implications of developments and actions. See also: Scenario, Scenario storyline.

Emissionscenario

A plausible representation of the future development of emissions of substances that are radiatively active (e.g., greenhouse gases (GHGs) or aerosols) based on a coherent and internally consistent set of assumptions about driving forces (such as demographic and socio-economic development, technological change, energy and land use) and their key relationships. Concentration scenarios, derived from emissionscenarios, are often used as input to a climate model to compute climate projections.

Sendai Framework for Disaster Risk Reduction

The Sendai Framework for DisasterRisk Reduction 2015-2030 outlines seven clear targets and four priorities for action to prevent new, and to reduce existing disasterrisks. The voluntary, non-binding agreement recognises that the State has the primary role to reduce disaster risk, but that responsibility should be shared with other stakeholders including local government, the private sector and other stakeholders, with the aim for the substantial reduction of disaster risk and losses in lives, livelihoods and health and in the economic, physical, social, cultural and environmental assets of persons, businesses, communities and countries.

Settlements

Places of concentrated human habitation. Settlements.can range from isolated rural villages to urban regions with significant global influence. They can include formally planned and informal or illegal habitation and related infrastructure. See also: Cities, Urban, Urbanisation.

Shared socio-economic pathways (SSPs)

See: Pathways

Shifting development pathways (SDPs)

In this report, shifting development pathways describes transitions.aimed at redirecting existing developmental trends. Societies may put in place enabling conditions to influence their future development pathways, when they endeavour to achieve certain outcomes. Some outcomes may be common, while others may be context-specific, given different starting points. See also: Development pathways, Shiftingdevelopment pathways to sustainability.

Sink

Any process, activity or mechanism which removes a greenhouse gas, an aerosol or a precursor of a greenhouse gas from the atmosphere. See also: Pool - Carbon and nitrogen, Reservoir, Sequestration, Sequestrationpotential, Source, Uptake.

Small Island Developing States (SIDS)

Small Island Developing States (SIDS), as recognised by the United Nations OHRLLS (UN Office of the High Representative for the Least Developed Countries, Landlocked Developing Countries and Small Island Developing States), are a distinct group of developing countries facing specific social, economic and environmental vulnerabilities. They were recognised as a special case both for their environment and development at the Rio Earth Summit in Brazil in 1992. Fifty-eight countries and territories are presently classified as SIDS by the UN OHRLLS, with 38 being UN member states and 20 being Non-UN Members or Associate Members of the Regional Commissions.

Social justice

See: Justice.

Social protection

In the context of development aid and climate policy, social protection usually describes public and private initiatives that provide income or consumption transfers to the poor, protect the vulnerable against livelihoodrisks, and enhance the social status and rights of the marginalized, with the overall objective of reducing the economic and social vulnerability of poor, vulnerable, and marginalized groups. In other contexts, social protection may be used synonymously with social policy and can be described as all public and private initiatives that provide access to services, such as health, education, or housing, or income and consumption transfers to people. Social protection policies protect the poor and. vulnerable against livelihood risks and enhance the social status and rights of the marginalized, as well as prevent vulnerable people from falling into poverty.

Solar radiation modification (SRM)

Refers to a range of radiation modification measures not related to greenhouse gas (GHG) mitigation.that seek to limit global warming. Most methods involve reducing the amount of incoming solar radiation reaching the surface, but others also act on the longwave radiation budget by reducing optical thickness and cloud lifetime.

Source

Any process or activity which releases a greenhouse gas, an aerosol.or a precursor of a greenhouse gas into the atmosphere. See also: Pool - carbon and nitrogen, Reservoir, Sequestration, Sequestrationpotential, Sink, Uptake.

Stranded assets

Assets exposed to devaluations or conversion to ‘liabilities’ because of unanticipated changes in their initially expected revenues due to innovations and/or evolutions of the business context, including changes in public regulations at the domestic and international levels.

Sustainable development (SD)

Development that meets the needs of the present without compromising the ability of future generations to meet their own needs and balances social, economic and environmental concerns. See also: Development pathways, Sustainable Development Goals (SDGs) .

Sustainable Development Goals (SDGs)

The 17 Global Goals for development for all countries established by the United Nations through a participatory process and elaborated in the 2030 Agenda for Sustainable Development , including ending poverty and hunger; ensuring health and well-being, education, gender equality, clean water and energy, and decent work; building and ensuring resilient and sustainable infrastructure, cities and consumption; reducing inequalities; protecting land and water ecosystems; promoting peace, justice and partnerships; and taking urgent action on climatechange. See also: Development pathways, Sustainable development (SD) .

Sustainable land management

The stewardship and use of land resources, including soils, water, animals and plants, to meet changing human needs, while simultaneously ensuring the long-term productive potential of these resources and the maintenance of their environmental functions.

Temperature overshoot

Exceedance of a specified global warming level, followed by a decline to or below that level during a specified period of time (e.g., before 2100). Sometimes the magnitude and likelihood of the overshoot is also characterized. The overshoot duration can vary from one pathway.to the next but in most overshoot pathways.in the literature and referred to as overshoot pathways in the AR6, the overshoot occurs over a period of at least one and up to several decades. See also: Overshoot Pathways.

Tipping point

A critical threshold beyond which a system reorganises, often abruptly and/or irreversibly. See also: Abrupt climate change, Irreversibility, Tipping element .

Transformation

A change in the fundamental attributes of natural and human systems.

Transformational adaptation

See: Adaptation.

Transition

The process of changing from one state or condition to another in a given period of time. Transition can be in individuals, firms, cities, regions and nations, and can be based on incremental or transformative change..

Just transitions

A set of principles, processes and practices that aim to ensure that no people, workers, places, sectors, countries or regions are left behind in the transition from a high-carbon to a low-carbon economy. It stresses the need for targeted and proactive measures from governments, agencies, and authorities to ensure that any negative social, environmental or economic impacts of economy-wide transitions are minimized, whilst benefits are maximized for those disproportionately affected. Key principles of just transitions include: respect and dignity for vulnerable groups; fairness in energy access and use, social dialogue and democratic consultation with relevant stakeholders; the creation of decent jobs; social protection; and rights at work. Just transitions could include fairness in energy, land use and climate planning and decision-making processes; economic diversification based on low-carbon investments; realistic training/retraining programs that lead to decent work; gender specific policies that promote equitable outcomes; the fostering of international cooperation and coordinated multilateral actions; and the eradication of poverty. Lastly, just transitions may embody the redressing of past harms and perceived injustices.

Urban

The categorisation of areas as “urban” by government statistical departments is generally based either on population size, population density, economic base, provision of services, or some combination of the above. Urban systems are networks and nodes of intensive interaction and exchange including capital, culture, and material objects. Urban areas exist on a continuum with rural areas and tend to exhibit higher levels of complexity, higher populations and population density, intensity of capital investment, and a preponderance of secondary (processing) and tertiary (service) sector industries. The extent and intensity of these features varies significantly within and between urban areas. Urban places and systems are open, with much movement and exchange between more rural areas as well as other urban regions. Urban areas can be globally interconnected, facilitating rapid flows between them, of capital investment, of ideas and culture, human migration, and disease. See also: Cities, City region, Peri-urban areas, Urban Systems, Urbanisation.

Urbanisation

Urbanisation is a multi-dimensional process that involves at least three simultaneous changes: 1)land use change: transformation of formerly rural settlements or natural land into urbansettlements; 2) demographic change: a shift in the spatial distribution of a population from rural to urban areas; and 3)infrastructure change: an increase in provision of infrastructure services including electricity, sanitation, etc. Urbanisation often includes changes in lifestyle, culture, and behaviour, and thus alters the demographic, economic, and social structure of both urban and rural areas. See also: Settlement , Urban, Urban Systems.

Vector-borne disease

Illnesses caused by parasites, viruses and bacteria that are transmitted by various vectors (e.g. mosquitoes, sandflies, triatomine bugs, blackflies, ticks, tsetse flies, mites, snails and lice).

Vulnerability

The propensity or predisposition to be adversely affected. Vulnerability encompasses a variety of concepts and elements including sensitivity or susceptibility to harm and lack of capacity to cope and adapt. See also: Hazard, Exposure, Impacts, Risk.

Water security

The capacity of a population to safeguard sustainable access to adequate quantities of acceptable-quality water for sustaining livelihoods, human well-being and socio-economic development, for ensuring protection against water-borne pollution and water-related disasters and for preserving ecosystems in a climate of peace and political stability.

Well-being

A state of existence that fulfills various human needs, including material living conditions and quality of life, as well as the ability to pursue one’s goals, to thrive and to feel satisfied with one’s life. Ecosystem well-being refers to the ability of ecosystems.to maintain their diversity and quality.

Editorial Team

Andreas Fischlin (Switzerland), Yonhung Jung (Republic of Korea), Noëmie Leprince-Ringuet (France), Chloé Ludden (Germany/France), Clotilde Péan (France), José Romero (Switzerland)

This Annex should be cited as: IPCC, 2023: Annex II: Acronyms, Chemical Symbols and Scientific Units [Fischlin, A., Y. Jung, N. Leprince-Ringuet, C. Ludden, C. Péan, J. Romero (eds.)]. In: Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change[Core Writing Team, H. Lee and J. Romero (eds.)]. IPCC, Geneva, Switzerland, pp. 131-133, doi:10.59327/IPCC/AR6-9789291691647.003.

Annex II

* For a full definition see also Annex I: Glossary

Definitions of additional terms are available in the IPCC Online Glossary: https://apps.ipcc.ch/glossary/

Note: An asterisk (*) indicates the term also appears in the Glossary. Page numbers in bold indicate page spans for the four Topics. Page numbers in italics denote figures, tables and boxed material.

2030 Agenda for Sustainable Development*, 52

A

Adaptation, 77, 84

characteristics of, 77, 84

co-benefits, 19, 21, 25 -26, 28 -29, 30-31, 33, 53, 55, 79, 87, 88, 95, 101 -102, 104 -106, 108, 110, 113

effective, 8 -10, 17-18, 19, 24 -25, 28 -33, 38, 43, 52 -53, 55 -56, 61 -63, 78, 79, 82, 92, 95 -96, 97, 99, 102, 104, 106 -107, 110 -114

emissions reductions and, 28 -29, 31, 102, 105, 110

finance, 8-9, 11, 31, 33, 53, 55, 57, 62, 111-112

finance gaps, 112

gap, 11, 57, 58, 61, 110

hard limits, 8, 61, 78, 92, 99

limits, 8, 15, 19 -20, 24 -26, 33, 57 -58, 61 -62, 71, 77, 78-79, 81, 87, 89, 92, 96, 97, 99, 108, 111

maladaptation, 8, 19, 25, 61 -62, 78 -79

options, 8 -10, 19, 21, 25, 26, 27, 28-31, 38, 52 -53, 54, 55 -56, 61 -63, 78, 80, 81, 86 -89, 92, 93, 95 -97, 102, 104, 105 -111, 113 -114

pathways, 3, 9 -10, 11-12, 17-18, 20 -21, 22-23, 23-24, 26, 31 -33, 38, 53, 57, 58 -60, 61, 63, 65-66, 68, 72, 75-77, 84, 85, 86, 86-89, 92 -93, 94, 96, 97, 98, 101 -102, 107, 110 -112, 114

planning and implementation, 8, 19, 32, 52, 55, 61 -62, 79

potential, 15, 16-17, 18 -19, 21, 26, 27, 28-31, 33, 50, 52, 55, 60, 72, 73-74, 77, 78, 82, 85, 85-88, 95-96, 99, 102, 103-104, 105 -106, 108, 109, 112, 114

soft limits, 8, 33, 57, 61, 62, 78, 111

sustainable development and, 21, 55, 88 -89

transformational, 29, 73, 77-78, 96, 105, 108

Adaptation gap*, 61

Adaptation limits*, 8, 19, 24, 25, 26, 61, 71, 77 -78, 89, 97, 108

hard limits*, 8, 61, 78, 92, 99

soft limits*, 8, 33, 57, 61 -62, 78, 111

Adaptation options, 8 -9, 19, 25, 25, 27, 27 -30, 52, 55 -56, 62, 78, 81, 88, 92, 95 -97, 97102, 103, 104, 106 -110

Adaptation potential, 106

Aerosol*, 4, 13, 42, 43, 63, 66, 69, 72, 82, 98

Afforestation*, 21, 27-28, 29, 56, 87 -88, 99, 103-104, 106, 108

Agricultural drought*. SeeDrought*

Agriculture, Forestry and Other Land Use (AFOLU)*, 5, 29, 44, 61, 67, 106, 110, 114

Agriculture, 5 -6, 7, 8, 21, 27, 29, 44, 49, 51 -52, 55, 60 -61, 78, 85, 87 -88, 95, 106, 113, 114

adaptation, 8, 29, 55, 61, 78, 88, 106

drought, 46, 48, 50, 55, 61

irrigation, 8, 55, 61, 71, 88

maladaptation, 61, 114

mitigation, 21, 2., 29, 44, 52, 60, 85, 87, 88, 94-95, 103-104, 106, 113

Agroforestry*, 8, 27, 29, 55 -56, 78, 87, 103, 106, 109, 110

Anthropogenic*, 4, 9, 19, 42, 43, 44, 45-46 , 63 , 69, 72, 77, 82, 83 , 85

emissions, See also Emissions

Arctic sea ice, 13, 46, 47, 69, 76, 98

observed changes, 5, 42

projected changes, 13, 14, 16, 70, 73, 98

Atlantic Meridional Overturning Circulation, 18, 78

Atmosphere, 5, 20, 21, 43, 46, 47, 58, 82, 86

Attribution. SeeDetection and attribution

B

Behavioural change*, 25, 28, 30, 86 -87, 97, 102, 107

Biodiversity*, 3, 6, 7, 15, 17, 18 -19, 21, 24, 26, 27, 29 -30, 38, 50, 55 -56, 71 -72, 74, 75-76, 77 -78, 88 -89, 92, 98 -99, 103, 106, 108, 110, 114

Bioenergy*, 23, 28, 87, 88, 95, 99, 104, 104, 106, 108

Bioenergy with carbon dioxide capture and storage (BECCS), 23, 88

Blue carbon*, 21, 87-88, 106

Blue infrastructure*, 29, 55, 105

Buildings, 5, 21, 22, 27-28, 29, 44, 52 -53, 56, 86, 93, 94, 103-104, 105, 110, 114

C

Carbon budget*, 19-20, 82, 83, 87, 121

Carbon cycle*, 9, 47, 63, 68

Carbon dioxide (CO2), 4, 19, 4 3, 60

emissions scenarios, 7-8, 9-10, 12, 17-18, 63, 65-66, 68-69, 75-77, 82, 83, 92, 98

projections, 8, , 9, 12, 14, 16, 58, 63, 68, 70, 74, 76, 77-78, 80-81, 83, 85, 101

radiative forcing and, 43

Carbon dioxide capture and storage (CCS)*, 87-88

Carbon dioxide removal (CDR)*, 19, 23, 60, 72, 85, 99

Carbon sequestration, 21, 27, 87, 88, 103

Carbon sinks, 13, 23, 82, 87

Cascading impacts*, 76, 97

Certainty, 32, 53, 108

Clean energy, 31, 107, 108

Climate change*, 3, 5 -7, 9, 13 -16, 18, 24, 25 -26, 28 -31, 33, 38, 42, 44, 46, 50 -53, 55, 61 -62, 63-64 , 65, 66, 68, 71 -72, 73-74, 77 , 78, 87 -89, 92 -93, 95, 97, 98 -99, 100, 101, 104 -109, 111 -112, 114

abrupt, 15, 18, 71, 77 -78

attribution of, 7, 50

beyond 2100, ., 15, 77

causes of, 62

drivers of, 6, 9, 38, 44, 50, 63, 127

future changes, 12, 18, 18, 68, 77, 81

irreversible or abrupt changes, 18

limiting, 18-21, 22-23, 26, 57 -58, 59-60 , 82, 84, 85-88, 92, 94-95, 95, 112

mitigation, 3, 4, 9 -11, 18, 2 0-21, 22-23, 25, 25-26, 27-28, 29-34, 38, 44, 52 -53, 54, 55-57,. 60, 61-62, 63-64, 65-66, 68, 77, 79, 82, 84 , 86, 85-89, 92 -93, 94, 95 -96, 97 , 101 -102, 103-104, 104 -106, 109-110, 113, 108 -115

timescales, 18, 77, 87

Climate extreme (extreme weather or climate event)*, 5, 42, 46, 50, 50, 76, 99, 100

Climate finance*, 9, 11, 53, 55, 62, 112, 122

adaptation, 9, 30, 33, 52-53, 55, 62, 96, 107-108, 111-115

mitigation, 10-11, 26, 30, 33-34, 52, 61-62, 88, 96, 101 -102, 105, 108, 111-115

Climate governance*, 32, 52 -53, 61, 108, 110

Climate justice*, 30 -31, 88, 96, 101, 110, 11 2

Climate literacy*, 9, 30, 73, 62, 107, 122

Climate Models, 16, 43, 73, 82

Climate resilient development (CRD)*, 24, 25 , 29, 31 -33, 88 -89, 92, 96, 97 , 101-102, 105, 111 -112, 114

Climate sensitivity*, 9, 12, 18, 43, 68, 77

Equilibrium climate sensitivity (ECS)*, 12, 18, 68, 77

Climate services*, 8, 27, 28-30, 55-56, 78, 103, 105, 107

Climate system*, 4, 12, 14, 18, 24, 43, 44, 46, 47, 63, 68-69, 70, 77, 82, 97

human influence on, 50

observed changes in, 5, 46, 47 , 48

responses of, 44

warming of, 3, 4, 11 -12, 15, 25, 38, 42, 43 , 47, 57, 68 -69, 71, 77, 84, 97

Climatic impact-driver (CID)*, 64, 65-66, 69, 87

CO2, 4-5, 9-13, 19-21, 22-23, 23, 27, 28-29, 32, 42, 43, 44, 45-46, 47, 51, 58, 59-60, 61, 63, 65, 68, 82, 83-85, 85, 86, 86-87, 93, 94-95, 104

CO2-equivalent emission (CO2-eq)*, 22

Coastal ecosystems, 17-18, 23, 75-77, 77, 98

Co-benefits, 19, 21, 25 -26, 28 -31, 33, 53, 55, 79, 87 -88, 95, 101 -102, 104 -106, 108, 110, 113

Compound weather/climate events*, 122

Confidence, 92

Cooperation, 24, 30, 32 -33, 53,57, 88, 96, 106, 108, 111, 112 -115

Coral reefs, 17, 18 -19, 61, 71, 75-76, 77, 98

Cost-effective, 9, 33, 56, 63, 96, 112

Costs of mitigation, 26, 88

Cryosphere, 3, 5, 15, 46, 51, 122

D

Decarbonization, 53

Decision making, 24, 30 -3 2, 52, 89, 101 -102, 105-106, 108, 114

Deforestation*, 10, 21, 29, 44, 53, 55, 87, 93, 94, 106, 114

Demand-side measures*, 21, 28 -29, 86, 102, 104 , 106

Detection and attribution*, 43, 50, 121

Developed / developing countries (Industrialised / developed / developing countries)*, 5, 8-9, 11, 26, 31, 33-34, 44, 52, 55, 57, 60, 61-62, 71, 86, 89, 96, 98-99, 102, 110-113

Development pathways*, 24, 25, 32, 33, 38, 53, 61, 72, 89, 96, 97, 102, 110-111

Diets, 26, 27, 29 -30, 50, 55, 103, 106 -108

Disaster risk management (DRM)*, 8, 27, 30, 55-56, 78, 103, 107

Displacement (of humans)*, 6, 7, 50, 51, 76-77, 107

Drought*, 7, 13, 14, 25, 29, 46, 48-50, 51, 55, 61, 69, 70, 71 -72, 76, 87, 97, 99, 100-101, 105

agricultural and ecological drought, 46, 48, 50, 69

E

Early warning systems (EWS)*, 8, 27, 30, 55-56, 78, 103, 106-107

Ecological drought*, 46, 48-50, 69

Economic growth, 9, 51

Economic instruments, 10, 31 -32, 52 -53, 107, 110

Economic losses, 6, 50 -52, 62

Ecosystem*, 3, 5, 7, 8, 15, 16-18, 18-19, 21, 23-2 5, 25, 27, 2 8-30, 38, 46, 49-50, 50 -51, 55 -56, 61-62, 64, 71 -72, 73-77, 77 -7 9, 80, 82, 8 7-89, 92, 95-96, 97, 9 7-99, 102, 103, 106, 108, 109-110, 114

management, 3, 8, 19, 21, 24-25, 27, 28-30, 38, 55 -56, 61-62, 78 -79, 80, 92, 95-96, 102, 103, 10 6, 108, 109-110, 114

risks, See also Risk*

Ecosystem-based adaptation (EbA)*, 8, 19, 55, 78, 80, 95, 106

Ecosystem services*, 27, 29-30, 55-56, 76, 78, 80, 88-89, 103, 106, 108, 114

Emission pathways*. See Emission scenario3, 9, 23, 38, 63, 84

Emissions, 4 -5, 7-8, 10, .9-13, 18 -21, 22-23, 23-24, 25, 25-26, 27-28, 28-34, 42, 43, 44, 45-46, 46, 49-50, 50 -53, 55, 57 -58, 58-60, 61, 63 , 65-66 , 68 -69, 72, 77, 77, 80-81 , 82, 83-85, 85, 86, 86-89, 92 -93, 94-95, 95, 97 , 98-99, 101 -102, 103-104, 104 -108, 110 -11 4

anthropogenic, 4 , 9 , 19 , 43, 42 -44 , 45-46, 63 , 69 , 72 , 77 , 82 , 83 , 85

CO2-equivalent, 4, 22, 44, 59 -60

drivers of, 6, 9, 38, 44, 50, 63

metrics, 4, 44

observed changes, 5, 42, 46, 47-50

reductions, 5, 10 -12, 18 -21, 21-22, 25, 26, 28, 28 -33, 44, 52 -55, 54, 57, 59. 60, 68 -69, 82, 84, 85-88, 92 -93, 95, 97, 101 -102, 104, 104 -105, 110, 112, 114

See also Emission pathways*

See also Emission scenarios*

Emission scenarios*, 9, 12, 63, 92

baseline, 17-18, 28, 43, 75-77, 102, 104

categories, 9, 12, 15, 20, 28, 44, 59, 63 -64 , 65-66, 68, 71, 84, 104

mitigation pathways, 9, 11, 20-21, 22-23, 26, 31, 38, 57, 62-63, 84 , 86, 86 -88, 93, 94-95, 101

modelled, 9-10, 11-12, 20 -23, 22, 33, 57, 59-60, 62 -63, 68, 84 -85, 8686-8 8, 92 -93, 95, 96, 111 -112

overview of, 28, 104

Representative Concentration Pathways (RCPs), 9, 63, 65

Shared socio-economic pathways (SSPs), 9, 63, 65

temperature and, 13, 16, 73-74 , 98

Enabling conditions (for adaptation and mitigation options)*, 21, 24, 25, 34, 61, 86, 95, 96, 97, 102, 113

Energy. See also Clean Energy, Fossil Fuels, Renewable Energy, 31, 107, 108

Energy access, 101

Energy demand, 10, 51, 53, 87

demand-side management, 10, 28

Energy efficiency, 10, 21, 27, 28, 53, 86 -88, 103, 104, 113, 114

Energy intensity, 5, 44, 53

Energy system, 6, 28, 50, 104, 109

policy instruments, 11, 21, 52 -53, 86, 110

transformation, 25, 29, 57, 61-62, 78, 89

Equality*. See also Equity, Inequality, 114

Equilibrium climate sensitivity (ECS)*, 12, 18, 68, 77

Equity*, 6, 9, 24, 25, 30-32, 49, 51, 52, 55, 60, 62, 63, 78, 88-89, 96, 97, 101-102

Exposure*, 15, 16, 18, 19, 30, 56, 62, 63-66, 71 -72, 74, 77, 78-79, 97 -98, 100, 107

reduction of, 55, 95, 104, 105-106, 128

Extinction risk, 71

Extreme weather events, 15, 17, 56, 71, 107

observed changes, 5, 42

precipitation, 5 -6, 7, 12 -13, 14, 15, 16, 29, 46, 47-50, 50 -51, 69, 70 , 73, 76, 87, 98 -99, 105

as Reason for Concern, 17 ,75

projections, 8 , 9, 12, 14, 16,. 58, 63, 68, 70, 74, 76, 77-78, 80-81, 83 , 85 , 101

risks due to, 66

sea level, 5 -6, 13, 15, 18, 23, 46, 50, 56, 68 -69, 75-77, 77, 79, 80-81, 87, 98, 100-101, 106

temperature, 4, 6, 7-9, 12 -13, 14, 16 -18, 18 -20, 42, 43 , 47, 50, 50, 58, 64 -66, 68 -69,. 70, 73-77, 77, 82, 83-85, 85, 86, 87, 98

F

Feasibility*, 19, 23, 25 -26, 27-28, 28, 34, 56, 61, 87, 92, 95 -96, 102, 103-104, 112, 114

Finance, 9 -11, 24, 25, 26, 30 -33, 52 -53, 55, 61 -62, 88 -89, 96, 97, 101 -102, 105, 107 -108, 110 -115

availability, 9, 3233, 62, 104, 111

barriers, 25, 32 -33, 55, 57, 61 -62, 97, 111 -112

mitigation, 9, 11, 24, 25, 32 -33, 51, 55, 61 -62, 89, 97, 107, 111 -112

private, 9, 11, 33, 55, 62, 111, 112

public, 9, 11, 32-33, 53, 55, 62, 86, 101, 107, 110 -11 2

See alsoClimate finance

Fire weather*, 7, 13, 51, 69, 72, 103, 124

Fisheries, 6, 7, 16-17, 27, 30, 50, 73-74, 76, 103, 106, 110, 112

Floods, 5, 15, 25, 51, 76, 97, 99

Food loss and waste*, 30, 55, 106

Food production, 6, 7, 15, 16, 50, 55, 73-74 , 76, 99

Food security*, 3, 5 -6, 17-18, 26, 29 -30, 38, 50 -51, 55 -56, 71, 74, 76-77, 87, 100, 106, 108, 114

Forests, 17, 18, 21, 28 -30, 56, 75, 77, 87, 88, 99, 104, 106, 108

afforestation, 27-28, 87, 103-104

deforestation, 10, 21, 29, 44, 53, 55, 87, 93, 94, 106, 114

reforestation, 21, 27, 29, 56, 87, 93, 103, 104, 106

Fossil Fuels, 4, 11, 21, 28, 30, 43, 44, 54, 62, 86 -87, 92, 95, 104, 108, 111

G

Glaciers, 5, 13, 46, 47, 69, 71

observed changes, 5, 42

projected changes, 13, 14,16, 70, 73, 98

Global warming*See also Warming, 3 -4, 9 -10, 11-13, 14, 15, 16-18, 18-21, 23 -24, 25, 26, 27, 30, 38, 42, 43, 50, 57 -58, 59-60, 63 -65 , 68 -69, 70, 71-72, 74 -77, 77 -79, 82, 83-84, 85-89, 92, 96, 95 -99, 104, 112, 113

of climate system, 12, 14, 18, 24, 43, 46, 47, 68, 70, 77, 97

CO2 emissions and, 19, 68, 82, 83, 85, 87, 92

feedbacks and, 82

human activities, 4, 42, 43

irreversibility of, 77

projections of, 14, 16, 68, 70, 74, 77, 81

timescales of, 18, 80

Global warming potential (GWP)*, 4, 19, 44, 60, 85

Governance, 8, 24, 25, 30 -33, 51 -53, 61, 72, 78, 87, 89, 96, 97, 99, 101, 108, 110 -112, 114

Governments 11, 2 5, 28, 33, 55, 89, 97, 104, 112

national, 8-10, 19, 22, 24, 26, 28, 32 -33, 44, 45, 49, 51 -53, 55, 57, 61 -62, 78, 89, 96, 102, 104, 108, 110 -113

Greenhouse gases (GHGs)*. See Emissions, 4, 20, 42, 43, 86

Green infrastructure*, 10, 27, 53, 103

Greenland ice sheet, 46, 47

Grey infrastructure*, 29

H

Hazard*, 15, 48, 51, 65-66, 71, 76-77, 97-98, 101

Heatwaves, 5, 13, 16-17, 29, 46, 48-50, 51, 69, 71-72, 73, 98-99, 105

Human health, 6, 15, 16, 18, 26, 29 -31, 42, 50 -51, 71, 73-74, 77, 88, 95, 102, 106 -107

Human security, 71

I

Ice Sheets, 13, 18, 69, 77

Impacts*. See also Observed changes, 3, 5 -6, 7, 14 -15, 16 -17, 18, 38, 42, 46, 49-50, 50-51, 63-66, 68, 71, 73-77

attribution of, 7, 50

cascading, 14 -15, 68, 71 -72, 76-77, 97 -99, 100-101, 105, 114

distribution of, 15, 71

future, 1, 3, 8, 12, 15, 60, 68, 98

global aggregate, 17, 71, 75, 88

irreversible, 5, 15, 18, 23, 24, 46, 68 -69, 71, 76, 77, 82, 87, 95

of climate change, 3, 9, 16, 30, 38, 46, 49, 51, 55, 63 , 72, 74, 87 -88, 92, 95, 99, 108, 109, 111

of extreme events, 5-6, 16, 29, 50-51, 74, 78, 97, 100, 104-105

severe, 6, 15, 25, 46, 50, 62, 69, 71, 77 -79, 87, 92, 97, 99, 101

timescales of, 18, 80

widespread, 3, 5 -6, . , 14, 15, 23, 28, 32, 38, 42, 51, 53, 70, 71 -72, 87, 104, 111, 114

Indigenous knowledge (IK)*, 25, 32, 89, 97, 101, 107

Indigenous Peoples*, 5, 15, 19, 21, 30 -32, 50 -53, 61 -62, 71, 88, 99, 101, 106, 108, 110

Industry, 5, 21, 22, 27-28, 29, 43, 44, 52 -53, 86, 93, 94, 102, 103, 104, 105, 110

emissions by, 22, 27, 32, 45-46, 53, 61, 94, 102, 110

mitigation potential, 27, 29, 87, 103-104, 106, 114

transition, 28, 31, 52, 77 -78, 86, 94, 96, 101 -102, 104

Inequality*. See also Equality, Equity, 15, 50 , 76, 98, 112

Informal settlement*, 15, 30, 50, 62, 98, 105

Information measures. See Climate literacy

Infrastructure*, 6, 7, 10, 15, 19 -20, 23, 25 -26, 27, 28 -31, 49-50, 50 -51, 53, 55, 58, 61, 71, 76, 77, 80, 83, 86 -87, 89, 92, 95 -96, 98 -99, 101 -102, 103-104, 104 -107, 109 -11 0, 114

blue infrastructure, 29, 105

Institutions, 32, 34, 51, 55, 60 -61, 110 -112

Integrated responses, 89

International cooperation, 24, 32 -33, 53, 57, 88, 96, 108, 111 -112

Investment, 17, 32 -33, 62, 75, 89, 105, 111 -113

Irreversibility*, 5, 15, 46, 71

irreversible impacts, 82

irreversible or abrupt changes, 18

J

Just transition*, 30-31, 52, 101-102

Justice*, 9, 24, 25, 30 -32, 63, 88 -89, 96, 97, 101, 110, 112, 114

climate justice, 30 -31, 88, 96, 101, 110, 112

social justice, 31, 101

K

Key risk*. See Risk, 15, 64, 71, 76-77

Kyoto Protocol, 10, 38, 52, 112

L

Land Use, Land-Use Change and Forestry (LULUCF)*, 5, 43, 93

Large-scale singular events, 15, 71, 77

Least Developed Countries (LDCs)*, 5, 9, 44, 71

Likelihood See Confidence, 3, 7, 9, 18 -20, 38, 47, 58, 63, 77 -78, 81 -84, 92

Livelihood*, 21, 23-24, 26, 27, 29-30, 50, 51, 55, 76, 80, 87, 92, 102, 110

Local knowledge (LK)*, 25, 97, 101, 107

Lock-in*, 26, 62, 78, 95-96

Loss and Damage, and losses and damages*, 52

Low-likelihood, high-impact outcomes*, 77

M

Maladaptation*, 8, 19, 25, 57, 61, 62, 78, 79, 97

Methane, 4, 12, 19, 21, 22, 23, 26, 27, 28 -29, 42, 43, 85, 87, 92 -93, 95, 103, 104

Migration*, 15, 27, 51-52, 98, 101, 104, 107

of humans, 16

of species, 5, 71, 77

Mitigation (of climate change*)9 -11, 18 , 22-23, 24, 25-26, 27-28, 30-31, 52 -53, 57-58, 59-60 , 61, 63, 68, 73-7 5, 86, 98, 103-104, 111, 113, 1 14-115

barriers to, 9, 25, 32, 33, 61 -62, 87, 92, 95, 97, 111

characteristics of, 77, 84

co-benefits of, 21, 88, 108

emissions reductions and, 28 -29, 31, 102, 105, 110

integrated approach, 29, 106

national and sub-national, 10, 52 -53, 110

Mitigation costs, 26, 95, 104

distribution of, 15, 71

Mitigation options, 9 -10, 26, 27-28, 29, 53, 54, 61, 63, 87 -89, 95, 103-104, 108, 109-110, 114

Mitigation pathways. See Mitigation, 9, 11, 20-21, 22-23, 26, 31, 38, 57, 63, 82, 84 , 86, 86 -88, 93, 95, 101

Mitigation potential*, 27, 29, 87, 103-104, 106, 114

Mitigation scenarios, 82

characteristics of, 77, 84

N

National governments. See Government, 28 , 104

Natural (climate) variability*, 8, 12-13, 98

Net zero CO2 emissions*, 19, 20, 21, 23, 23, 60, 61, 68, 85, 86, 93

Net zero GHG emissions*, 19, 20, 22, 60, 85

New Urban Agenda*, 52

O

Observed changes, 5, 42, 46, 47-50

extreme events, 5 -6, 16, 29, 50 -51, 74, 78, 97, 100, 104, 105

impacts of, 3, 5, 16, 18, 30, 32, 38, 46, 51, 53, 74 , 76, 87, 108, 111, 114

in climate system, 18

in emissions, 33, 58, 68, 84, 85, 87, 111, 112

Ocean, 4 -6, 7, 13, 15, 16-18, 29 -30, 38, 42, 46, 47, 49, 50 -51, 68 -69, 72, 73, 75-76, 77, 82, 87, 98, 102, 106, 108, 109-110, 114

acidification, 6, ., 13, 46, 47, 50, 69, 72, 76

heat content, 47

observed changes, 5, 42, 47-49

projected changes, 13, 14, 16, 70, 73, 98

warming of, 47

Ocean acidification, 6, 7, 13, 46, 50, 69, 72

impacts of, 3, 5, 16, 18, 30, 32, 38, 46, 51, 53, 74, 87, 108, 111, 114

projections, 8, 9, 12, 14, 16, 58, 63, 68, 70, 74, 78, 80-81, 83, 85, 101

risks associated, 18, 23, 77

Overshoot (pathways/scenarios)*, 9 -11, 10, 20 -21, 21-23, 23, 57 -58, 58-59, 63, 65 , 68, 71, 82, 84, 85, 86, 87, 92, 93, 94-95, 102

characteristics, 33, 38, 77, 84, 113

See also Impacts*

P

Paris Agreement, 10 -11, 38, 52, 57, 60, 62, 112

Pathways*, 3, 9 -10, 10-12, 17-18, 20 -21, 21-22, 22-24, 25, 26, 31 -33, 38, 53, 57 -61, 63, 65-66 , 68, 72, 75-77, 82, 84 -85, 86, 86-89, 92 -93, 94-95, 97, 101 -102, 107, 110 -112, 114

categories of, 12, 64, 68

development pathways, 24, 25, 32, 33, 38, 53, 61, 72, 89, 96, 97, 102, 110 -112

emission pathways, 3, 9, 23, 38, 63, 84

overshoot pathways, 59, 87, 94, 127, 129

shared socio-economic pathways (SSPs), 9, 63

Permafrost, 5, 13, 17, 69, 75, 77, 87, 98

Planetary health*, 24, 89, 102, 108, 114

Policies, 8 -11, 18, 22, 24 -26, 28, 30 -33, 51 -53, 55, 58-60, 63, 68 -69, 77, 86, 89, 96, 101 -102, 104, 106 -108, 110 -115

adaptation, 8, 18, 24, 25-26, 3 0-32, 55, 73-74, 75, 89, 111, 114 -115

assessing, 15, 31, 50, 66, 71, 78, 101

distributional effects, 105

equity, 9, 24, 25, 3 0-32, 49, 55, 60, 62, 63 , 88 -89, 96, 97, 101 -102, 108, 110 -112, 114

finance, 9 -11, 24, 25, 26, 30 -33, 52 -53, 55, 61 -62, 88 -9, 96, 97, 101 -102, 105, 107 -108, 110 -115

mitigation, 9 -11, 18, 22-23, 24, 25-26, 27-28, 30-31, 52 -53, 57-58, 59-60, 61, 63, 68, 73-7., 86, 98,. 103-104, 111, 113, 1 14-115

sectoral, 16, 19 -20, 23 , 28, 32, 33, 34, 56, 62, 74, 77, 78-79, 86, 89, 94-95, 96, 104, 108, 110 -112, 114 -115

sustainable development and, 3, 21, 38, 55, 88, 89

technology, 10 -11, 21, 25, 28, 30 -34, 52 -53, 54, 61, 68, 86, 96, 97, 102, 104, 107, 108, 111,-113

Population growth, 17, 75, 63

Poverty, 3, 25, 30, 38, 50 , 51-52, 62, 76, 88, 97, 101 -102, 108, 112

Precipitation, 5 -6, 7, 12 -13, 14, 15, 16, 29, 46, 47-50, 50 -51, 69, 70 , 73, 76, 87, 98 -99, 105

extreme events, 5 -6, 16, 29, 50 -51, 74, 78, 97, 100, 104, 105

observed changes, 5, 42

projected changes, 13, 98

Private finance. See Finance, 9, 11, 33, 62, 111, 112

Private sector, 9, 24, 25, 55, 61, 89, 97, 107, 111, 112

Public finance. See Finance, 33, 111, 112

R

Radiative forcing, 4, 9, 13, 42, 43, 62-63, 65, 98

Reasons for Concern (RFCs)*, 15, 17-18, 64, 71, 75-77

Reforestation*, 21, 27, 29, 56, 87, 93, 103-104, 106

Regions, 4-6, 7, 8, 10-11, 14 , 16, 17-19, 24, 2 5, 2 8-33, 38, 4 2, 44, . 46, 50-53, 55, 576 0-6 2, 64, 68 -69, 70, 71 -72, 73-74,. 76, 77 -7 8, 88-89, 97 , 95-99, 100, 101-102, 103, 1 04, 106, 108, 110 -11 2, 114

irreversible changes, 15, 18, 68, 71, 77

key risks, 15, 64, 71, 76-77

See also Impacts*

Renewable energy, 21, 53, 54, 88, 104, 105

Representative Concentration Pathways (RCPs)*, 9, 63 , 65

Residual risk*, 78, 105

Resilience*, 19, 23, 28 -31, 55, 78, 87, 101 -102, 104 -107, 110

Restoration*, 8, 21, 27, 29 -30, 55 -56, 77, 88, 103-104, 105-106, 108

Risk*, 3, 6, 8 -9, 12, 14 -15, 16 -18, 18 -19, 21, 23 -24, 26 , 25-26, 29, 32, 33, 38, 42, 50 -52, 55, 61 -62, 63-66, 68, 71 -72, 73-74, 77 -79, 80, 82, 87 -89, 92, 95, 97, 97 -99, 100-101, 101, 104 -108, 110 -112

causes of, 62

from climate change, 6, 14 -15, 26, 51, 64, 72, 88, 99

future, 4, 7-. , 12, 14 -15, 16-18, 18, 20, 24, 25, 28, 44, 58, 60, 61, 63 -66, 68 -69, 73-74, 77, 80-81, 87 -89, 92, 95 -98, 97, 101, 102, 104, 107

key risks, 15, 64, 71, 76-77

of adaptation, 8 -9, 18, 19, 25 -26, 33, 38, 55 -56, 61 -62, 77, 7 8-79, 88, 92, 95, 99, 101 -102, 107, 109 , 111

of mitigation, 26, 27, 28, 31, 57, 88, 89, 95, 103, 102, 109, 112 -114

region-specific, 61

unavoidable, 15, 18, 30, 77, 80, 85, 108

uneven distribution of, 15, 71

Risk management/reduction. See also Disaster risk management , 52,

Rural areas, 15, 98

S

Scenario*. See Emission Scenario*, Emission Pathway*andPathways*

Sea ice, 13, 46, 47, 69, 76, 98

arctic, 4, 5, 13, 16 -17, 18, 26, 42, 46, 47, 50 -51, 69, 71, 73-74, 76, 77, 93, 98

observed changes, 5, 42, 46, 47-50

projected changes, 13, 14, 16, 70, 73, 98

Sea level, 5 -6, 13, 15, 17-18, 23, 46, 47, 50, 56, 68, 69, 75-77, 77, 79, 80-81, 87, 98, 100-101, 106

extremes, 5 -6, 7, 12, 14, 42, 46, 48-50, 50 -51, 69, 70, 76, 98 -99

observed changes, 5, 42

Sea level rise, 5 -6, 7, 13, 15, 17-18, 18, 23, 46, 47, 50, 56, 68, 75-77, 79, 80-81, 87, 98, 100-101 , 106

contributions to, 3, 5, 28, 38, 43, 44, 104, 119

observed, 77, 80-81, 89, 92

projected, 100-101

risks associated with, 18, 23, 77, 112

variability in, 12, 14, 70

Seasonal, 7-8, 46, 47, 49-50, 69, 72

Sectors, 5 -6, 7, 8, 10 -11, 15, 19 -21, 22, 24, 25, 27-28, 29 -31, 33, 44, 51 -53, 54, 55 -57, 60 , 61-62, 64, 68, 71 -72, 76, 78 -79, 82, 86, 89, 93, 94, 95 -96, 97, 99, 101, 101 -102, 104 -108, 110 -112, 113, 114

GHG emissions by, 32, 45-46, 53, 102, 110

key risks, 15, 64, 71, 76-77

policy instruments, 11, 21, 52 -53, 86, 110

See also Adaptation*

See also Mitigation*

Settlements*, 7, 15, 18, 23, 27, 28-29, 31, 49-51, 62, 71, 76, 80, 87, 89, 98 -99, 10 3, 105-106

Shared socio-economic pathways (SSPs)*, 9, 63, 65

Shifting development pathways (SDPs)*, 32, 34, 102, 112

Sink*, 13, 22-23, 28, 42, 44, 82, 87, 94, 104, 106

Small Island Developing States (SIDS)*, 5, 26, 44, 51, 98

Snow cover, 13, 46, 47, 51, 69

Social justice*, 31, 101

Social protection*, 26, 28, 30 -31, 55, 96, 101, 106 -108

Solar Radiation Modification (SRM)*, 72

Source*, 50, 82

Species range shifts, 49

Stranded assets*, 25 -26, 58, 62, 95

Subsidies, 11, 32, 53, 102, 107, 110

Sustainable development (SD)*, 108, 109, 110, 114

climate policy and, 52

equity and, 24, 25, 31-32, 53, 91, 101

Sustainable Development Goals* (SDGs), 6, 30, 33, 52, 96, 101, 108, 109, 1 14