Absolute error

The absolute error of an observation x is the absolute deviation of x from its ―true value.

Absolute frequency

The absolute frequency of a variate, as distinct from the relative frequency, namely the ratio of the frequency to the total frequency of all variate values.


The number of individuals or related measure of quantity (such as biomass) in a population, community or spatial unit.

Acceptance rule

Logical or arithmetic condition applied to a data item or data group that must be met if the data are to be considered correct.


Accountability is the responsibility for the deterioration of the natural environment, implying the allocation of environmental costs to the economic activities that cause such deterioration.

Accounting standards

Accounting standards are methodologies and disclosure requirements for the preparation and presentation of financial statements.

Accrual rate

The rate at which pension benefits builds up as member service is completed in a defined benefit plan.

Acid deposition

Any form of deposition on water, land and other surfaces that increases their acidity by contamination with acid pollutants, such as sulphur oxides, sulphates, nitrogen oxides and nitrates, or ammonium compounds.


Change in environment’s natural chemical balance caused by an increase in the concentration of acidic elements.


A measure of how acid a solution may be. A solution with a pH of less than 7.0 is considered acidic.


The IPCC defines adaptation as “the process of adjustment to actual or expected climate and its effects”. It further states that “in human systems, adaptation seeks to moderate or avoid harm or exploit beneficial opportunities. In some natural systems, human intervention may facilitate adjustment to expected climate and its effects” (IPCC, AR V, WG 2, 2014). Adaptation is one of the two major policy responses to the issue of global environmental climate change, the other being mitigation (IPCC, AR V, WG 2,2014). 

Adaptive capacity

The potential or ability of a system, region or community to adapt to the effects or impacts of a particular set of changes.

Administrative data

Administrative data is the set of units and data derived from an administrative source.


A collection of airborne solid or liquid particles, with a typical size between 0.01 and 10 μm, that reside in the atmosphere for at least several hours.


Establishment of forest plantations on land that is not classified as forest.

Air pollution

Degradation of air quality with negative effects on human health, the natural or built environment, due to the introduction by natural processes or human activity in the atmosphere of substances (gases, aerosols) which have a direct (primary pollutants) or indirect (secondary pollutants) harmful effect.(IPCC sr15/pdf/sr15)

Air pollution index

An air pollution index (API) is a quantitative measure that describes ambient air quality. The index is obtained by combining figures for various air pollutants into a single measurement.

Air quality standards

Air quality standards refer to levels of air pollutants prescribed by regulations that may not be exceeded during a specified time in a defined area.

Algal beds

Reef top surface feature dominated by algae cover, usually brown algae (such as Sargassum or Turbinaria).

Alien species (also non-native, non-indigenous, foreign, exotic)

Species introduced outside its normal distribution.


Measures the wind speed and transmits wind speed data to the controller

Anthropogenic emissions

Emissions of greenhouse gases (GHGs), precursors of GHGs and aerosols caused by human activities. These activities include the burning of fossil fuels, deforestation, land use and land use changes (LULUC), livestock production, fertilisation, waste management, and industrial processes. (IPCC sr15/pdf/sr15)










Anthropogenic removals

Anthropogenic removals refer to the withdrawal of GHGs from the atmosphere as a result of deliberate human activities. These include enhancing biological sinks of CO2 and using chemical engineering to achieve long term removal and storage. Carbon capture and storage (CCS) from industrial and energy-related sources, which alone does not remove CO2 in the atmosphere, can reduce atmospheric CO2 if it is combined with bioenergy production (BECCS) (IPCC sr15/pdf/sr15)


The farming of aquatic organisms in inland and coastal areas, involving intervention in the rearing process to enhance production and the individual or corporate ownership of the stock being cultivated.

Aquatic ecosystem

Basic ecological unit composed of living and non-living elements interacting in an aqueous milieu.


An underground geological formation or group of formations, containing usable amounts of groundwater that can supply wells and springs.

Arable land

Land under temporary crops (double-cropped areas are counted only once), temporary meadows for mowing or pasture, land under market and kitchen gardens, and land temporarily fallow (less than five years).

Archetype of vulnerability

A specific, representative pattern of the interactions between environmental change and human well-being.

Area sampling

A method of sampling when no complete frame of reference is available. The total area under investigation is divided into small sub-areas which are sampled at random or by some restricted random process.

Aridity index

The long-term mean of the ratio of mean annual precipitation to mean annual potential evapotranspiration in a given area.


Biological diversity means the variability among living organisms from all sources including, inter alia, 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 (UN, 1992). (IPCC sr15/pdf/sr15)


Organic waste from agricultural, livestock, and lumber industry products, dead trees, foliage, etc., and is considered a renewable energy source. Biomass can be used as fuel and is most often burned to create steam that powers steam turbine generators. It is also used to make transportation fuels like ethanol and biodiesel, and chemicals like pyrolysis oil that can be burned like oil to produce energy.( clean energy resource teams)


Is the use of biomass to generate electricity. Biopower system technologies include ‘direct-firing,’ ‘cofiring,’ ‘gasification,’ ‘pyrolysis,’ and ‘anaerobic digestion.’ Most biopower plants use direct-fired systems. Paper mills, the largest current producers of biomass power, generate electricity or process heat as part of the process for recovering pulping chemicals. Also referred to as ‘biomass power.’(brodies.com)


Carbon budget

This term refers to three 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, landuse change emissions, ocean and land CO2 sinks, and the resulting atmospheric CO2 growth rate. This Approval Session Glossary IPCC SR1.5 Do Not Cite, Quote or Distribute 1-8 Total pages: 55 is referred to as the global carbon budget; (2) the estimated cumulative amount of global carbon dioxide emissions that that is estimated to limit global surface temperature to a given level above a reference period, taking into account global surface temperature contributions of other GHGs and climate forcers; (3) the distribution of the carbon budget defined under (2) to the regional, national, or sub-national level based on considerations of equity, costs or efficiency.(IPCC, Sr 1.5,2018)

Carbon cycle

The term used to describe the flow of carbon (in various forms, e.g., as carbon dioxide (CO2), carbon in biomass, and carbon dissolved in the ocean as carbonate and bicarbonate) through the atmosphere, hydrosphere, terrestrial and marine biosphere and lithosphere. In this report, the reference unit for the global carbon cycle is GtCO2 or GtC (Gigatonne of carbon = 1 GtC = 1015 grams of carbon. This corresponds to 3.667 GtCO2). (IPCC, SR1.5,2018)

Carbon dioxide capture and storage (CCS)

A process in which a relatively pure stream of carbon dioxide (CO2) from industrial and energyrelated 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 Carbon dioxide capture and utilisation (CCU), Bioenergy with carbon dioxide capture and storage (BECCS), and Sequestration. ). (IPCC, SR1.5, 2018)

Carbon Offsets

Carbon offsetting is a method of using economics to balance the impact of greenhouse gases in the atmosphere.  Individuals and businesses are encouraged to track their carbon output and purchase "offsets" that will serve to reduce or eliminate that carbon output.  The simple example is to plant a tree, or pay someone to plant a tree, that will consume a certain amount of CO2 over it's lifetime.( dasolar.com)

Carbon price

The IPCC defines  Cabon price asThe price for avoided or released carbon dioxide (CO2) or CO2-equivalent emissions. This may refer to the rate of a carbon tax, or the price of emission permits. In many models that are used to assess the economic costs of mitigation, carbon prices are used as a proxy to represent the level of effort in mitigation policies.(IPCC,SR1.5,2018)

Carbon sequestration

is the process involved in carbon capture and the long-term storage of atmospheric carbon dioxide or other forms of carbon to mitigate or defer global warming. This is one of the major strategies proposed in order to reduce atmospheric and marine accumulation of greenhouse gases, which are emitted as a result of  burning of fossil fuels. Carbon dioxide is generally naturally captured from the atmosphere through biological, chemical, and physical processes, however given the large quantities of CO2 released into the atmosphere due to fossil fuel burning, this process needs to be significantly enhanced in order to compensate for the additional emissions. In recent years, several artificial processes have been designed to produce similar effects. These include, but are not limited to large-scale, artificial capture and sequestration of industrially produced CO  using reservoirs, subsurface saline aquifers, aging oil fields, ocean water, or other carbon sinks.(Wikipedia)

Carbon sinks

Carbon sinks are natural or artificial reservoirs, which accumulate and store some carbon-containing chemical compound for an indefinite period of time. Carbon sinks perform this function of removal of atmospheric carbon dioxide (CO2) through a process referred to as carbon sequestration. Since the ratification of the Kyoto Protocol, public awareness around the importance of CO2 sinks has significantly increased. This has resulted in the promotion of their use as a form of carbon offset, necessary for mitigation of atmospheric carbon dioxide. Through the course of the past decade, several different strategies have been designed and promoted in order to enhance the process of carbon sequestration, and in the increase of numbers of carbon sinks across the world.(Wikipedia)


Chlorofluorocarbons or CHCs are often used in refrigeration, solvents, air conditioning, insulation, aerosol propellants and in packaging. Their utility emerges from the fact that they do not get destroyed in the lower atmosphere. Instead, CFCs drift into the upper atmosphere where, under suitable conditions, they break down ozone, thus resulting in depletion of the ozone layer which protects the earth from UV radiations of the sun. These greenhouse gases are covered under the 1987 Montreal Protocol. These gases have already been to a large extent, are also currently being replaced by other compounds. Some alternatives which have emerged in the past few decades have been hydrochlorofluorocarbons and hydrofluorocarbons. Both of these are greenhouse gases covered under the Kyoto Protocol (IPCC, ar5_wgII_spma)

Clean Development Mechanism (CDM)

A mechanism defined under Article 12 of the Kyoto Protocol through which investors (governments or companies) from developed (Annex B) countries may finance greenhouse gas (GHG) emission reduction or removal projects in developing countries (Non-Annex B), and receive Certified Emission Reduction Units (CERs) for doing so. The CERs can be credited towards the commitments of the respective developed countries. The CDM is intended to facilitate the two objectives of promoting sustainable development (SD) in developing countries and of helping industrialized countries to reach their emissions commitments in a cost-effective way. (IPCC sr15/pdf/sr15)

Climate change

The IPCC defines Climate change as “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. Note that the 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 natural climate 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”.( IPCC,ARV,WG2,2014)

Climate feedback

An interaction in which a perturbation in one climate quantity causes a change in a second and the change in the second quantity ultimately leads to an additional change in the first. A negative feedback is one in which the initial perturbation is weakened by the changes it causes; a positive feedback is one in which the initial perturbation is enhanced. The initial perturbation can either be externally forced or arise as part of internal variability. (IPCC sr15/pdf/sr15)

Climate justice

The IPCC defines Climate 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. This definitions builds upon the one used by the Mary Robinson Foundation - Climate Justice. (IPCC, SR 1.5,2018)

Climate model

The IPCC defines Climate model as A numerical representation of the climate system based on the physical, chemical and biological properties of its components, their interactions and feedback processes and accounting for some of its known properties. The climate system can be represented by models of varying complexity; that is, for any one component or combination of components a spectrum or hierarchy of models can be identified, differing in such aspects as the number of spatial dimensions, the extent to which physical, chemical or biological processes are explicitly represented, or the level at which empirical parametrizations are involved. There is an evolution towards more complex models with interactive chemistry and biology. Climate models are applied as a research tool to study and simulate the climate and for operational purposes, including monthly, seasonal and interannual climate predictions.(IPCC,SR1.5,2018)

Climate resilience

Climate resilience refers to the capacity of socio-ecological systems to: (a) absorb external stress and to continue the maintenance of ecosystem functions despite those stresses. Such stresses are often imposed upon ecosystems as a result of changing climatic conditions; and (b) adapt, reorganize, and evolve into other desirable configurations which can enhance the overall sustainability of the entire ecosystem , thus resulting in better preparedness of the system for future impacts of climatic changes.(Wikipedia)

Climate services

Climate services refers to information and products that enhance users' knowledge and understanding about the impacts of climate change and/or climate variability so as to aid decision-making of individuals and organizations and enable preparedness and early climate change action. Products can include climate data products. (IPCC sr15/pdf/sr15)

Climate system

The IPCC defines climate system is the highly complex 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 evolves in time under the influence of its own internal dynamics and because of external forcings such as volcanic eruptions, solar variations and anthropogenic forcings such as the changing composition of the atmosphere and land-use change. (IPCC, SR 1.5,2018)

Climate target

Climate target refers to a temperature limit, concentration level, or emissions reduction goal used towards the aim of avoiding dangerous anthropogenic interference with the climate system. For example, national climate targets may aim to reduce greenhouse gas emissions by a certain amount over a given time horizon, for example those under the Kyoto Protocol. (IPCC sr15/pdf/sr15)

Climate variability

Climate variability refers to variations in the mean state and other statistics (such as standard deviations, the occurrence of extremes, etc.) of the climate on all spatial and temporal scales beyond that of individual weather events. Variability may be due to natural internal processes within the climate system (internal variability), or to variations in natural or anthropogenic external forcing (external variability). (IPCC sr15/pdf/sr15)


The IPCC defines Deforestation as Conversion of forest to non-forest. For a discussion of the term forest and related terms such as afforestation, reforestation, and deforestation see the IPCC Report on Land Use, Land-Use Change and Forestry (IPCC, 2000). See also the Report on Definitions and Methodological Options to Inventory Emissions from Direct Human-induced Degradation of Forests and Devegetation of Other Vegetation Types (IPCC,ar4 2003).


The IPCC defines Desertification as Land degradation in arid, semi-arid, and dry sub-humid areas resulting from various factors, including climatic variations and human activities. Further, the United Nations Convention to Combat Desertification (UNCCD) defines land degradation as a reduction or loss in arid, semi-arid, and dry sub-humid areas of the biological or economic productivity and complexity of rainfed cropland, irrigated cropland, or range, pasture, forest and woodlands resulting from land uses or from a process or combination of processes, including those arising from human activities and habitation patterns, such as: (i) soil erosion caused by wind and/or water; (ii) deterioration of the physical, chemical, and biological or economic properties of soil; and (iii) long-term loss of natural vegetation(IPCC ar4, wg2)

Detection and attribution

Detection of change is defined as the process of demonstrating that climate or a system affected by climate has changed in some defined statistical sense, without providing a reason for that change. An identified change is detected in observations if its likelihood of occurrence by chance due to internal variability alone is determined to be small, for example, (IPCC sr15/pdf/sr15)

Disaster risk management (DRM)

Processes for designing, implementing, and evaluating strategies, policies, and measures to improve the understanding of disaster risk, foster disaster risk reduction and transfer, and promote continuous improvement in disaster preparedness, response, and recovery practices, with the explicit purpose of increasing human security, well-being, quality of life, and sustainable development. (IPCC sr15/pdf/sr15)

Early warning systems (EWS)

The IPCC defines EWS as  The set of technical, financial and institutional capacities needed to generate and disseminate timely and meaningful warning information to enable individuals, communities and organizations threatened by a hazard to prepare to act promptly and appropriately to reduce the possibility of harm or loss. Dependent upon context, EWS may draw upon scientific and/or Indigenous knowledge. 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 (an example is coral bleaching alerts), in agriculture (for example, warnings of ground frost, hailstorms) and in fisheries (storm and tsunami warnings). This glossary entry builds from the definitions used in UNISDR (2009) andIPCC(2012a).(IPCC,Sr1.5,2018)

Earth system model (ESM)

A coupled atmosphere–ocean general circulation model in which a representation of the carbon cycle is included, allowing for interactive calculation of atmospheric CO2 or compatible emissions. Additional components (e.g., atmospheric chemistry, ice sheets, dynamic vegetation, nitrogen cycle, but also urban or crop models) may be included. (IPCC sr15/pdf/sr15)


The IPCC defines Ecosystem as An ecosystem is a functional unit consisting of living organisms, their non-living 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 .(IPCC, SR 1.5,2018)

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(IPCC sr15/pdf/sr15)

Emission scenario

A plausible representation of the future development of emissions of substances that are radiatively active (e.g., greenhouse gases (GHGs), 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 emission scenarios, are often used as input to a climate model to compute climate projections(IPCC sr15/pdf/sr15)

Emissions trading

A market-based instrument aiming at meeting a mitigation objective in an efficient way. A cap on GHG emissions is divided in tradeable emission permits that are allocated by a combination of auctioning and handing out free allowances to entities within the jurisdiction of the trading scheme. Entities need to surrender emission permits equal to the amount of their emissions (e.g., tonnes of CO2). An entity may sell excess permits to entities that can avoid the same amount of emissions in a cheaper way. Trading schemes may occur at the intra-company, domestic, or international level (e.g., the flexibility mechanisms under the Kyoto Protocol and the EU-EUTS) and may apply to carbon dioxide (CO2), other greenhouse gases (GHGs), or other substances. (IPCC sr15/pdf/sr15)

Energy efficiency

The IPCC defines Energy efficiency as the ratio of output or useful energy or energy services or other useful physical outputs obtained from a system, conversion process, transmission or storage activity to the input of energy (measured as kWh kWh-1, tonnes kWh-1 or any other physical measure of useful output like tonne-km transported). Energy efficiency is often described by energy intensity. In economics, energy intensity describes the  ratio of economic output to energy input. Most commonly energy efficiency is measured as input energy over a physical or economic unit, i.e. kWh USD-1 (energy intensity), kWh tonne-1. For buildings, it is often measured as kWh m-2, and for vehicles as km liter-1or liter km-1. Very often in policy "energy efficiency" is intended as the measures to reduce energy demand through technological options such as insulating buildings, more efficient appliances, efficient lighting, efficient vehicles, etc.( IPCC,Sr1.5,2018)

Energy security

The goal of a given country, or the global community as a whole, to maintain an adequate, stable and predictable energy supply. Measures encompass safeguarding the sufficiency of energy resources to meet national energy demand at competitive and stable prices and the resilience of the energy supply; enabling development and deployment of technologies; building sufficient infrastructure to generate, store and transmit energy supplies and ensuring enforceable contracts of delivery. (IPCC sr15/pdf/sr15)


The degree to which climate goals and response options are considered possible and/or desirable. Feasibility depends on geophysical, ecological, technological, economic, social and institutional conditions for change. Conditions underpinning feasibility are dynamic, spatially variable, and may vary between different groups. (IPCC sr15/pdf/sr15)

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 (FAO, 2001). (IPCC sr15/pdf/sr15)

Geothermal Energy

Geothermal energy harnesses the heat from within the earth.  Typically, the heat is used to create steam which spins a turbine and generates electricity.  Geothermal heat pumps are used for home heating and cooling by using the ground temperature air to regulate the temperature in the house.  (dasolar.com)

Global warming

The IPCC defines Global warming as  An increase in global mean surface temperature (GMST) averaged over a 30-year period, relative to 1850-1900 unless otherwise specified. For periods shorter than 30 years, global warming refers to the estimated average temperature over the 30 years centred on that shorter period, accounting for the impact of any temperature fluctuations or trend within those 30 years.(IPCC, SR 1.5,2018)

Greenhouse gas

The IPCC defines Greenhouse gas as Greenhouse gases are those gaseous constituents of the atmosphere, both natural and anthropogenic, that absorb and emit radiation at specific wavelengths within the spectrum of terrestrial radiation emitted by the earth's surface, the atmosphere itself, and by clouds. This property causes the greenhouse effect. Water vapour (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4) Final Government Draft Glossary IPCC SR1.5 Do Not Cite, Quote or Distribute 1-27 Total pages: 55 and ozone (O3) are the primary GHGs in the earth's atmosphere. Moreover, there are a number of entirely human-made GHGs in the atmosphere, such as the halocarbons and other chlorine- and bromine-containing substances, dealt with under the Montreal Protocol. Beside CO2, N2O and CH4, the Kyoto Protocol deals with the GHGs sulphur hexafluoride (SF6), hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs). (IPCC, SR 1.5,2018)

Green infrastructure

The interconnected set of natural and constructed ecological systems, green spaces and other landscape features. It includes planted and indigenous trees, wetlands, parks, green open spaces and original grassland and woodlands, as well as possible building and street level design interventions that incorporate vegetation. Green infrastructure provides services and functions in the same way as Approval Session Glossary IPCC SR1.5 Do Not Cite, Quote or Distribute 1-27 Total pages: 55 conventional infrastructure. This definition builds from Culwick and Bobbins (2016). (IPCC sr15/pdf/sr15)


The IPCC defines Halocarbons as A collective term for the group of partially halogenated organic species, which includes the chlorofluorocarbons (CFCs), hydro chlorofluorocarbons (HCFCs), ydrofluorocarbons (HFCs), halons, methyl chloride and methyl bromide. Many of the halocarbons have large Global Warming Potentials. The chlorine and bromine-containing halocarbons are also involved in the depletion of the ozone layer(IPCC, SR 1.5, 2018)


The IPCC defines Impacts as “Climate change refers to 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. Note that the 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 natural climate 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 cause IPCC,ARV,WG2,2014)

Kyoto Protocol

The IPCC defines The Kyoto Protocol to the United Nations Framework Convention on Climate Change (UNFCCC) is an international treaty adopted in December 1997 in Kyoto, Japan, at the Third Session of the Conference of the Parties (COP3) to the UNFCCC. It contains legally binding commitments, in addition to those included in the UNFCCC. Countries included in Annex B of the Protocol (mostly OECD countries and countries with economies in transition) agreed to reduce their anthropogenic greenhouse gas (GHG) emissions (carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulphur hexafluoride (SF6)) by at least 5%  below 1990 levels in the first commitment period (2008-2012). The Kyoto Protocol entered into force on 16 February 2005 and as of May 2018 had 192 Parties (191 States and the European Union). A second commitment period was agreed in December 2012 at COP18, known as the Doha Amendment to the Kyoto Protocol, in which a new set of Parties committed to reduce GHG emissions by at least 18% below 1990 levels in the period from 2013 to 2020. However, as of May 2018, the Doha Amendment had not received sufficient ratifications to enter into force.(IPCC, SR 1.5)


The IPCC defines Impacts as “Technological change and changes in activities that reduce resource inputs and emissions per unit of output. Although several social, economic and technological policies would produce an emission reduction, with respect to climate change, mitigation means implementing policies to reduce greenhouse gas emissions and enhance sinks. Renewable energy deployment is a mitigation option when avoided greenhouse gas emissions exceed the sum of direct and indirect emissions”(IPCC,SRREN)

Net-zero emissions

The IPCC defines Net-zero emissions as  Net-zero emissions are achieved when emissions of greenhouse gases to the atmosphere are balanced by anthropogenic removals. Where multiple greenhouse gases are involved, the quantification of net-zero emissions depends on the climate metric chosen to compare emissions of different gases (such as Global warming potential, global temperature change potential, and others, as well as the chosen time horizon).(IPCC,Sr1.5,2018)

Ocean acidification

The IPCC defines Impacts as “Increased concentrations of CO2 in sea water causing a measurable increase in acidity (i.e., a reduction in ocean pH). This maylead to reduced calcification rates of calcifying organisms such as corals, molluscs, algae and crustacean”. Ocean acidification is the ongoing decrease in the pH of the Earth's oceans, caused by the uptake of carbon dioxide (CO2) from the atmosphere.[2] Seawater is slightly basic (meaning pH > 7), and ocean acidification involves a shift towards pH-neutral conditions rather than a transition to acidic conditions (pH < 7).[3] An estimated 30–40% of the carbon dioxide from human activity released into the atmosphere dissolves into oceans, rivers and lakes.[4][5] To achieve chemical equilibrium, some of it reacts with the water to form carbonic acid. Some of the resulting carbonic acid molecules dissociate into a bicarbonate ion and a hydrogen ion, thus increasing ocean acidity (H ion concentration). Between 1751 and 1996, surface ocean pH is estimated to have decreased from approximately 8.25 to 8.14,[6] representing an increase of almost 30% in H ion concentration in the world's oceans.[7][8] Earth System Models project that, within the last decade, ocean acidity exceeded historical analogues[9] and, in combination with other ocean biogeochemical changes, could undermine the functioning of marine ecosystems and disrupt the provision of many goods and services associated with the ocean beginning as early as 2100
(IPCC, ar4, wg2)


The IPCC defines Ozone, the triatomic form of oxygen (O3), is a gaseous atmospheric constituent. In the troposphere, it is created both naturally and by photochemical reactions involving gases resulting from human activities (smog). Tropospheric ozone acts as a greenhouse gas. In the stratosphere, it is created by the interaction between solar ultraviolet radiation and molecular oxygen (O2). Stratospheric ozone plays a dominant role in the stratospheric radiative balance. Its concentration is highest in the ozonelayer.(IPCC,Sr,1.5,2018)

Paris Agreement

The IPCC defines The Paris Agreement under the United Nations Framework Convention on Climate Change (UNFCCC) was adopted on December 2015 in Paris, France, at the 21st session of the Conference of the Parties (COP) to the UNFCCC. The agreement, adopted by 196 Parties to the UNFCCC, entered into force on 4 November 2016 and as of May 2018 had 195 Signatories and was ratified by 177 Parties. One of the goals of the Paris Agreement is “Holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels”, recognising that this would significantly reduce the risks and impacts of climate change. Additionally, the Agreement aims to strengthen the ability of countries to deal with the impacts of climate change. The Paris Agreement is intended to become fully effective in 2020.(IPCC, Sr 1.5,2018)


The conversion of light into electricity through the displacement of electrons and the current created as a result.  Photovoltaics are the basis for the operation of solar panels. (dasolar.com)

Renewable Energy Certificate (REC)

A REC is the property right to the environmental benefits associated with generating renewable electricity. For instance, homeowners who generate solar electricity are credited with 1 solar REC for every MWh of electricity they produce. Utilities that have to fulfill an RPS requirement can purchase these RECs on the open market. ( cleanenergyresourceteams)

Renewable Resources

Renewable energy resources are naturally replenishable, but flow-limited. They are virtually inexhaustible in duration but limited in the amount of energy that is available per unit of time. Some (such as geothermal and biomass) may be stock-limited in that stocks are depleted by use, but on a time scale of decades, or perhaps centuries, they can probably be replenished. Renewable energy resources include: biomass, hydro, geothermal, solar and wind. In the future they could also include the use of ocean thermal, wave, and tidal action technologies. Utility renewable resource applications include bulk electricity generation, on-site electricity generation, distributed electricity generation, non-grid-connected generation, and demand reduction (energy efficiency) technologies. ( cleanenergyresourceteams)

Research and Development (R&D)

Research is the discovery of fundamental new knowledge. Development is the application of new knowledge to develop a potential new service or product. Basic power sector R&D is most commonly funded and conducted through the Department of Energy (DOE), its associated government laboratories, university laboratories, the Electric Power Research Institute (EPRI), and private sector companies. ( cleanenergyresourceteams)


The IPCC defines Impacts as The capacity of social, economic, and environmental systems to cope with a hazardous event or trend or disturbance, responding or reorganizing in ways that maintain their essential function, identity, and structure, while also maintaining the capacity for adaptation, learning, and transformation. (IPCC Ar5, Wg 2)

Sustainable Development Goals (SDGs)

The IPCC defines 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 wellbeing, 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 climate change.(IPCC, Sr 1.5,2018)


The IPCC defines Vulnerability as 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 Contextual vulnerability and Outcome  vulnerability.(IPCC,Ar5,wg2)


Zero-carbon electricity is created from renewable energy sources.  Solar Energy is an example of electricity that can be generated from the sun's energy without any carbon emissions into the environment.  It is therefore cleaner and more desirable. (dasolar.com)