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Accuracy

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Accuracy is a relative measure of the exactness of an emission or removal estimate. Estimates should be accurate
in the sense that they are systematically neither over nor under true emissions or removals, so far as can be judged,
and that uncertainties are reduced so far as is practicable. Appropriate methodologies conforming to guidance on
good practices should be used to promote accuracy in inventories. Accuracy should be distinguished fromprecision as illustrated below.

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Illustration of Accuracy and Precision: (a) inaccurate but precise; (b) inaccurate and imprecise; (c) accurate
but imprecise; and (d) precise and accurate.

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(a)

(b)

(c)

(d)

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Activity

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A practice or ensemble of practices that take place on a delineated area over a given period of time.

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Data on the magnitude of a human activity resulting in emissions or removals taking place during a given periodof time. Data on energy use, metal production, land areas, management systems, lime and fertilizer use and waste
arisings are examples of activity data.

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An artificial storage containing water for agricultural (irrigation) or pastoral (stock watering) uses. They are
typically unlined and constructed using a combination of earthen embankments and the natural topography on thelandscape. They can range in size from very small farm dams (< 50 m2) to very large (> 10 km2). <<https://eros.usgs.gov/cubbie-station-queensland-australia-1987–2013 >>.

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Material or formation originating outside the water body.

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relationship.

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Activity data

Agricultural Pond

Allochthonous

Allometric Model: An allometric model is a formula that quantitatively describes an allometric
Allometry: The term allometry refers to the proportional relationship between the relative dimensional
relationships or growth rates.

Anaerobic

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Conditions in which oxygen is not readily available. These conditions are important for the production of methane
emissions. Whenever organic material decomposes in anaerobic conditions (in landfills, flooded rice fields, etc.)
methane is likely to be formed.

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A soil developed in volcanic ash. Generally andosols have good drainage and are prone to fertility problems.

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An artifical storage containing water for the production of aquatic animals or plants. They are typically unlined
and constructed using a combination of earthen embankments and the natural topography on the landscape. They
can range in size from (< 50 m2) to (> 10 km2).

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The sum of the values divided by the number of values.

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Auto producer

Andosol

Aquaculture Pond

Arithmetic mean

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An enterprise which generates electricity or heat for its own use and/or sells it as a secondary activity i.e., not as
its main business.

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Material or formation originating from inside the water body.

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The opposite of forecasting. Predicting conditions in the past from current conditions.

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By-product oils from petrochemical processing of refinery products which are generally returned to the refinery
for further processing into petroleum products.

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The starting year for the inventory. Currently this is typically 1990.

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A systematic error of the observation method, whose magnitude in most cases is unknown. It can be introduced
by using measuring equipment that is improperly calibrated, by selecting items from a wrong population or byfavouring certain elements of a population, etc. For example: Estimating the total fugitive emission from gas
transport and distribution using only measurements of leakage from high/medium pressure pipelines can lead tobias if the leakage in the lower pressure distribution network (which is significantly more difficult to measure) isneglected.

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For the purpose of this report, biochar is defined as a solid material generated by heating biomass to a temperaturein excess of 300 °C under conditions of controlled and limited oxidant concentrations to prevent combustion.
These processes can be classified as either pyrolysis (in which oxidants are excluded), or gasification (in which
oxidant concentrations are low enough to generate syngas).

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Any fuels derived from biomass, either deliberately grown or from waste products. Peat is not considered a biofuelin these guidelines due to the length of time required for peat to re-accumulate after harvest.

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Carbon derived from biogenic (plant or animal) sources excluding fossil carbon. Note that peat is treated as a fossil
carbon in these guidelines as it takes so long to replace harvested peat.

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Composting and anaerobic digestion of organic wastes, such as food waste, garden/park waste and sludge, toreduce volume in the waste material, stabilisation of waste, and destruction of pathogens in the waste material.
This includes mechanical-biological treatment.

3435(1) The total mass of living organisms in a given area or of a given species usually expressed as dry weight.

3637(2) Organic matter consisting of or recently derived from living organisms (espically regarded as fuel) excluding
peat. Includes products, by-products and waste derived from such material.

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A gas, volatile liquid, or chemical that generates gas during the foaming process. The gas creates bubbles or cells
in the plastic structure of a foam.

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Bootstrap technique is a type of computationally intensive statistical methods which typically uses repeatedresampling from a set of data to assess variability of parameter estimates.

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See polar/boreal.

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Calcium carbide

Autochthonous
Back-casting
Backflows
Base year
Bias

Biochar

Biofuels

Biogenic carbon

Biological treatment of waste

Biomass

Blowing agent (for foam production)
Bootstrap technique
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Calcium carbide is used in the production of acetylene, in the manufacture of cyanamide (a minor historical use),
and as a reductant in electric arc steel furnaces. It is made from calcium carbonate (limestone) and carboncontaining reductant (e.g., petroleum coke).

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An artificial waterway typically constructed with a uniform cross-section to provide navigation or to transportwater for irrigation, hydropower, town water supplies, etc. They may be earthen structures or they may haveconcrete linings. “Canals are generally long and narrow, with a uniform width and depth, and have a single outlet.”<https://www.ramsar.org/news/ramsar-topics-report-on-canal-estates>> accessed 10 Apr 18

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The balance of the exchanges of carbon between carbon pools or within one specific loop (e.g., atmosphere –biosphere) of the carbon cycle.

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A measure used to compare different greenhouse gases based on their contribution to radiative forcing. The
UNFCCC currently (2005) uses global warming potentials (GWPs) as factors to calculate carbon dioxide
equivalent (see below).

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Categories are subdivisions of the four main sectors Energy; Industrial Processes and Product Use (IPPU);
Agriculture, Forestry and Other Land Use (AFOLU); and waste. Categories may be further divided into subcategories.

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Data collected by interrogation or count of an entire population.

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A generic term for a waterway that encompasses creeks, streams, rivers, canals, ditches etc.

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Halocarbons containing only chlorine, fluorine, and carbon atoms. CFCs are both ozone-depleting substances(ODSs) and greenhouse gases.

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Chronosequences consist of measurements taken from similar but separate locations that represent a temporalsequence in land use or management, for example, years since deforestation. Efforts are made to control all otherbetween-site differences (e.g., by selecting areas with similar soil type, topography, previous vegetation).
Chronosequences are often used as a surrogate for experimental studies or measurements repeated over time at thesame location.

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The climatic sub-domain into which lands are grouped for the purposes of inventory calculations.

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Statistical definition: The coefficient of variation, vx is the ratio of the population standard deviation, σx, and mean,
μx, where vx = σx /µx. It also frequently refers to the sample coefficient of variation, which is the ratio of the sample
standard deviation and sample mean. 1

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See: Combined Heat and Power (CHP) generation.

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Combined heat and power (CHP), also known as cogeneration, is the simultaneous production of both electricity
and useful heat for application by the producer or to be sold to other users with the aim of better utilisation of theenergy used. Public utilities may utilise part of the heat produced in power plants and sell it for public heating
purposes. Industries as auto-producers may sell part of the excess electricity produced to other industries or toelectric utilities.

Canal

Carbon budget

Carbon dioxide equivalentCategory

CensusChannelChlorofluorocarbons (CFCs)
Chronosequence

Climate sub-domain

Coefficient of variation

Cogeneration

Combined heat and power (CHP)

1 ‘Coefficient of variation’ is the term, which is frequently replaced by ‘error’ in a statement like ‘the error is 5%’.

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Comparability

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Comparability means that estimates of emissions and removals reported by countries in inventories should becomparable among countries. For this purpose, countries should use agreed methodologies and formats for
estimating and reporting inventories.

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Completeness means that an inventory covers all sources and sinks and gases included in the IPCC Guidelines forthe full geographic coverage in addition to other existing relevant source/sink categories which are specific toindividual countries (and therefore may not be included in the IPCC Guidelines).

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The term ‘confidence’ is used to represent trust in a measurement or estimate. Having confidence in inventory
estimates does not make those estimates more accurate or precise; however, it will eventually help to establish aconsensus regarding whether the data can be applied to solve a problem. This usage of confidence differs
substantially from the statistical usage in the term confidence interval.

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The value of the quantity for which the interval is to be estimated is a fixed but unknown constant, such as theannual total emissions in a given year for a given country. The confidence interval is a range that encloses the true
value of a unknown fixed quantity with a specified confidence (probability). Typically, a 95 percent confidence
interval is assumed. From a traditional statistical perspective, the 95 percent confidence interval has a 95 percent
probability of enclosing the true but unknown value of the quantity. An alternative interpretation is that theconfidence interval is a range that may safely be declared to be consistent with observed data or information. The
95 percent confidence interval is enclosed by the 2.5th and 97.5th percentiles of the PDF.

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Consistency means that an inventory should be internally consistent in all its elements over a period of years. An
inventory is consistent if the same methodologies are used for the base year and all subsequent years and if
consistent data sets are used to estimate emissions or removals from sources or sinks. An inventory using different
methodologies for different years can be considered to be consistent if it has been estimated in a transparent manner
taking into account the guidance in Volume 1 on good practice in time series consistency.

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Mutual dependence between two quantities. See correlation coefficient.

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A number lying between –1 and +1, which measures the mutual dependence between two variables that are
observed together. A value of +1 means that the variables have a perfect linear relationship; a value of –1 meansthat there is a perfect inverse linear relation; and a value of 0 means that there is no straight line relation. It isdefined as the covariance of the two variables divided by the product of their standard deviations.

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Data for either activities or emissions that are based on research carried out on sites either in that country orotherwise representative of that country.

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(When applied to aircraft) All aircraft activities that take place at altitudes above 914 metres (3000 feet) including
any additional climb or descent operations above this altitude. There is no upper limit.

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A structure used to contain water. Typically constructed with mineral sediment or concrete. Large dams are definedby the International Commission on Large Dams (ICOLD) to be structures greater than 15 m in height.

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These are the elevated gas emissions that occur as water is released from a dam and experiences sudden changes
in pressure, temperature and turbulence. These changes cause air-water exchange processes to occur at muchgreater rates than in surface waters as the released water approaches a new equilibrium with the environment
downstream following Le Chatelier's principle. In the case of dams the change in the hydrostatic pressure before
and after water passing throught turbines affects this balance.

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Also, water released from dams is typically released into a stilling basin designed to dissipate much of the turbulent
energy of the flow in order to prevent excessive bank erosion in the natural river channel downstream. The

CompletenessConfidence

Confidence interval

Consistency

Correlation

Correlation coefficientCountry-specific data
CruiseDam

Degassing emissions

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increased water column turbulence greatly increases the air-water gas transfer rate for a given dissolved gas
concentration. In some cases, water may be discharged through needle valves into the air, which provides very
high air-water contact area leading to rapid gas release.

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A decision tree is a flow chart describing the specific ordered steps which need to be followed to develop an
inventory or an inventory component in accordance with the principles of good practice.

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9The gas flux across the air-water interface governed by diffusion. For measuring diffusive fluxes, the most popularmethod employs floating chambers. Frequently estimated using the Thin Boundary Layer model of gas transfer.

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An emission of greenhouse gases that has been relocated in space (and possibly in time) but unchanged in quantity.
For example, remineralisation and emission of CO2 of 1 kg of soil C assumed to occur in an agricultural field may
actually occur downstream in a river, reservoir or ocean if that 1 kg of soil C is carried into the stream network as
a consequence of rainfall. The carbon is still converted to CO2 but enters the atmosphere at a location downstreamof the carbon source.

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Sum of all inorganic carbon species in solution (e.g. carbonate, bicarbonate, carbonic acid, carbon dioxide).

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Organic carbon remaining in solution after filtering the sample, typically using a 0.45 micrometer filter.

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A distribution function or cumulative distribution function F(x) for a random variable X specifies the probabilityP(X ≤ x) that X is less than or equal to x.

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A long, narrow excavation dug in the earth, typically unlined, often with a uniform cross-section. They are mostoften used to provide drainage alongside roadways and from agricultural fields and to convey water for irrigation.

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The total greenhouse gas emissions that occur downstream of a dam including both degassing emissions and the
diffusive emission from the river downstream of the dam.

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A ditch used for drainage.

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The area around the perimeter of a reservoir or pond that is intermittently exposed to the air as a result of waterlevel changes.

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The flux of gas carried by bubbles from sediments through to the water column to the atmosphere.

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The measurement of material fluxes by correlating high-frequency turbulent velocity fluctuations with turbulent
concentration fluctuations. Also referred to as eddy correlation i.e. micrometeorological method that uses
differences in concentration associated with turbulence in the air to quantify net vertical gas exchange.

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A coefficient that quantifies the emissions or removals of a gas per unit activity. Emission factors are often basedon a sample of measurement data, averaged to develop a representative rate of emission for a given activity level
under a given set of operating conditions.

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The release of greenhouse gases and/or their precursors into the atmosphere over a specified area and period oftime. (UNFCCC Article 1.4)

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Energy recovery

Decision tree

Diffusive emission

Displaced emission

Dissolved Inorganic Carbon (DIC)
Dissolved Organic Carbon (DOC)
Distribution function

Ditch

Downstream emissions
Drainage channel
Drawdown zone

Ebullitive emission

Eddy flux measurement

Emission factor

Emissions

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A form of resource recovery in which the organic fraction of waste is converted to some form of usable energy.
Recovery may be achieved through the combustion of processed or raw refuse to produce steam through thepyrolysis of refuse to produce oil or gas; and through the anaerobic digestion of organic wastes to produce methane
gas.

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Increased CH4 recovery produced by the injection of CO2 into coal seams.

78Pertaining to the epilimnion of a stratified water body.

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The uppermost region of a density-stratified reservoir. Frequently defined as the region above the strongest
temperature gradient in the water column. It always includes, but is not limited to, the surface mixing layer – theisothermal region of actively turbulent water just below the air-water interface.

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The process of calculating emissions and/or removals.

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Natural or anthropogenic process of nutrient enrichment of a water body which leads to increases in algal biomass.

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Evaporative emissions fall within the class of fugitive emissions and are released from area (rather than point)sources. These are often emissions of Non-Methane Volatile Organic Compounds (NMVOCs), and are produced
when the product is exposed to the air – for example in the use of paints or solvents.

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Carbon in non-energy uses of fossil fuels (feed stocks, reductant and non-energy products) excluded from fuelcombustion.

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A carefully considered, well-documented qualitative or quantitative judgement made in the absence of unequivocal
observational evidence by a person or persons who have a demonstrable expertise in the given field.

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Fossil fuels used as raw materials in chemical conversion processes to produce primarily organic chemicals and,to a lesser extent, inorganic chemicals.

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Distinguishes first uses (and related emissions) from later non-energy uses of fossil fuels. For example, first-use
emissions from lubricants are those which take place as a result of oxidation during use as a lubricant. Usedlubricants may be used subsequently for heat raising as waste oils.

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Deliberate burning of natural gas and waste gas/vapour streams, without energy recovery.

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Closed container that floats on the surface of the water used to quantifying greenhouse gas emissions from thewater surface. The time-dependent change in gas concentration within the floating chamber is a direct
measurement of the gas flux.

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The operation of a reservoir to reduce peaks in river discharge.

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A proxy for the estimation of anthropogenic emissions and removals from flooded land designated as “managed”
land prior to flooding.

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The volume of water or gas passing through an imaginary plane at an instant of time [units are length3 time-1:eg,
m3 s-1, cfs, ML d-1, Ln min-1].

Enhanced coal bed methane (recovery)
Epilimnetic
Epilimnion

Estimation

Eutrophication

Evaporative emissions

Excluded carbon

Expert judgement
Feedstock
First use

Flaring

Floating chamber

Flood Control

Flooded land proxy
Flow rate

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Fluorocarbons

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Halocarbons containing fluorine atoms, including chlorofluorocarbons (CFCs), hydrochlorofluorocarbons(HCFCs), hydrofluorocarbons (HFCs), and perfluorocarbons (PFCs).

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(1) Raw materials, such as limestone, dolomite, lime, and silica sand, which are used to reduce the heat or otherenergy requirements of thermal processing of minerals (such as the smelting of metals). Fluxes also may servea dual function as a slagging agent.

89(2) The rate of flow of any liquid or gas, across a given area; the amount of this crossing a given area in a given
time. E.g., "Flux of CO2 absorbed by forests".

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Carbon derived from fossil fuel or other fossil source.

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Any substance burned as a source of energy such as heat or electricity. See also Primary Fuels and Secondary
Fuels.

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Within the Guidelines fuel combustion is the intentional oxidation of materials within an apparatus that is designed
to provide heat or mechanical work to a process, or for use away from the apparatus.

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Wood used directly as fuel.

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Emissions that are not emitted through an intentional release through stack or vent. This can include leaks fromindustrial plant and pipelines.

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A device deployed underwater to capture bubbles.

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Global Warming Potentials (GWP) are calculated as the ratio of the radiative forcing of one kilogramme
greenhouse gas emitted to the atmosphere to that from one kilogramme CO2 over a period of time (e.g., 100 years).

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Good Practice is a set of procedures intended to ensure that greenhouse gas inventories are accurate in the sensethat they are systematically neither over- nor underestimates so far as can be judged, and that uncertainties are
reduced so far as possible.

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Good Practice covers choice of estimation methods appropriate to national circumstances, quality assurance andquality control at the national level, quantification of uncertainties and data archiving and reporting to promotetransparency.

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A term used for data obtained by measurements on the ground, usually as validation for remote sensing, e.g.,satellite data.

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A computer modelling tool developed by the International Hydropower Association (IHA) in collaboration with
the UNESCO Chair for Global Environmental Change for the assessment of GHG emissions from reservoirs allaround the world. Using readily available input data, the tool provides a cost effective way to more accurately
assess net GHG emissions.

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The G-res tool uses a modelling methodology based on current scientific knowledge and over 500 empiricalmeasurements from more than 200 reservoirs worldwide.

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It builds on a conceptual framework developed in cooperation with researchers from the University of Québec at
Montreal (UQAM), the Norwegian Foundation for Scientific and Industrial Research (SINTEF) and the Natural
Resources Institute of Finland (LUKE). <https://www.hydropower.org/gres>

Flux

Fossil carbon
Fuel

Fuel combustion
Fuel wood

Fugitive Emissions
Funnel trap

Global warming potential
Good Practice

Ground truth
G-res

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Harvested wood products

Harvested wood products (HWP) according to the IPCC good practice guidance (2003) include wood and paper
products. It is related to harvest and manufacture of wood products and the use and disposal of wood.

Hydrocarbon

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Strictly defined as molecules containing only hydrogen and carbon. The term is often used more broadly to include
any molecules in petroleum which also contains molecules with S, N, or O An unsaturated hydrocarbon is anyhydrocarbon containing olefinic or aromatic structures.

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Halocarbons containing only hydrogen, chlorine, fluorine and carbon atoms. Because HCFCs contain chlorine,
they contribute to ozone depletion. They are also greenhouse gases.

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Halocarbons containing only hydrogen, fluorine and carbon atoms. Because HFCs contain no chlorine, bromine,or iodine, they do not deplete the ozone layer. Like other halocarbons, they are potent greenhouse gases.

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Hydrochlorofluorocarbons (HCFCs)
Hydrofluorocarbons (HFCs)
Hydrofluoroethers (HFEs)

Chemicals composed of hydrogen, fluorine and carbon atoms, with ether structure. Because HFES contain nochlorine, bromine, or iodine, they do not deplete the ozone layer. Like other halocarbons, they are potent
greenhouse gases.Hypolimnetic Pertaining to the hypolimnion.

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Hympolimnion

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Hypoxic

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The hypolimnion is the region of colder water at the bottom of a thermally stratified water body. It lies below themeatalimnion (or thermocline) – the region with the strongest temperature gradient – and it may contain a weaktemperature gradient. In many reservoirs, the hypolimnion can be anoxic (no oxygen) for many months each year
because vertical transport of dissolved gases from above occurs mainly by slow diffusive processes across themetalimnion. This can lead to the accumulation of large concentrations of dissolved CH4 released from the bottom
sediments.
Depletion of dissolved oxygen in aquatic environments to levels that are detrimental or fatal to aerobicorganisms
often caused by eutrophication.

Independence

Two random variables are independent if there is a complete absence of association between how their sample
values vary. The most commonly used measure of the lack of independence between two random variables is thecorrelation coefficient.

Inflow

The water that enters a water body (e.g. pond, lake, reservoir). In addition to surface flows (streams, rivers), inflow
may also include precipitation and groundwater inputs.

Irrigation channel

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An open channel that transports water in order to irrigate agricultural land.

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A key category is one that is prioritised within the national inventory system because its estimate has a significant
influence on a country's total inventory of greenhouse gases in terms of the absolute level of emissions andremovals, the trend in emissions and removals, or uncertainty in emissions or removals. Whenever the term key
category is used, it includes both source and sink categories.

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See key category.

Key category

Key source

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Kilns

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A tubular heating apparatus used in the manufacture of cement, lime and other materials. The calcination reaction
may take place in the kiln itself, or, where so-equipped, it may partly or completely take place in a preheater and/or
precalciner apparatus ahead of the kiln.

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The type of vegetation , rock, water etc. covering the earth’s surface.

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The type of activity being carried out on a unit of land.

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Note: in Volume 4 (AFOLU), broad land-use categories are defined in Chapter 2. It is recognized that thesecategories are a mixture of land cover (e.g., Forest, Grassland, Wetlands) and land use (e.g., Cropland, Settlements)
classes.

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Municipal solid waste contains significant portions of organic materials that produce a variety of gaseous products
when deposited, compacted, and covered in landfills. Anaerobic bacteria thrive in the oxygen-free environment,
resulting in the decomposition of the organic materials and the production of primarily carbon dioxide and methane.
Carbon dioxide is likely to leach out of the landfill because it is soluble in water. Methane, on the other hand,which is less soluble in water and lighter than air, is likely to migrate directly to the atmosphere.

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Land coverLand use

Landfill gas

Large dams

A dam with a height of 15 metres or greater from lowest foundation to crest or a dam between 5 metresand 15 metres impounding more than 3 million cubic metres. (See ICOLD Constitution, Page 3)

LTO (landing and take-off) cycle

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All aircraft activities that occur under 914 metres (3 000 feet) including idling aircraft engines, taxi-out, take-off,climb up to 914 metres, descend, approach and taxi-in. Note: some gatherers of statistics count either single takeoff or landing as one cycle; however, it is both one take-off and one landing that together define the LTO cycle.

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Lubricants are hydrocarbons produced from distillate or residue, and they are mainly used to reduce friction
between bearing surfaces. This category includes all finished grades of lubricating oil, from spindle oil to cylinderoil, and those used in greases, including motor oils and all grades of lubricating oil base stocks.

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Waste materials produced by domestic livestock which can be managed for agricultural purposes. When manure
is managed in a way that involves anaerobic decomposition, significant emissions of methane can result.

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The mean is a value around which values sampled from a probability distribution tend to lie. The sample mean orarithmetic average is an estimator for the mean. It is an unbiased and consistent estimator of the population mean
(expected value) and is itself a random variable with its own variance value. The sample mean is the sum of values
divided by the number of values:

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x =

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The use of direct measurements to compute GHG fluxes from a system.

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The median or population median is a value which divides the integral of a probability density function (PDF) into
two halves. For symmetric PDFs, it equals the mean. The median is the 50th population percentile.

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The sample median is an estimator of the population median. It is the value that divides an ordered sample into
two equal halves. If there are 2n + 1 observations, the median is taken as the (n + 1)th member of the orderedsample. If there are 2n, it is taken as being halfway between the nth and (n + 1)th .

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Production of methane by microorganisms (methanogenic bacteria) during the decomposition of organic matter.

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Mode

Lubricants

Manure
Mean

1 n
∑ xi
n i

( xi , where i = 1,…., n are items of a sample).Measurement-based

approachMedianMethanogenic production

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The mode of a distribution is the value which has the highest probability of occurrence. Distributions can have one ormore modes. In practice, we usually encounter distributions with only one mode. In this case, the mode or population
mode of a PDF is the measure of a value around which values sampled from a probability distribution tend to lie.

4
5
6The sample mode is an estimator for the population mode calculated by subdividing the sample range into equal
subclasses, counting how many observations fall into each class and selecting the centre point of the class (orclasses) with the greatest number of observations.

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9

A model is a quantitatively-based abstraction of a real-world situation which may simplify or neglect certain
features to better focus on its more important elements.

10
11

Example: the relationship that emissions equal an emission factor times an activity level is a simple model. The
term ‘model’ is also often used in the sense of a computer software realisation of a model abstraction.

12
13
14
15
16

Model-based approach

The application of (typically) statistical or process-based models that employ indirect measurements to infer GHG
fluxes from a system of interest. For example, a model-based estimate of a pollutant flux could be computed as
the product of an assumed concentration and a measured flow rate, whereas the corresponding measurement-based
estimate would use a measured concentration and a measured flow rate.

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18
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21
22
23
24
25

In these guidelines a Monte Carlo method is recommended to analyse the uncertainty of the inventory. The
principle of Monte Carlo analysis is to perform the inventory calculation many times by computer, each time withthe uncertain emission factors or model parameters and activity data chosen randomly (by the computer) within
the distribution on uncertainties specified initially by the user. Uncertainties in emission factors and/or activity
data are often large and may not have normal distributions. In this case the conventional statistical rules for
combining uncertainties become very approximate. Monte Carlo analysis can deal with this situation by generating
an uncertainty distribution for the inventory estimate that is consistent with the input uncertainty distributions on
the emission factors, model parameters and activity data.

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Primary or secondary fossil fuels which are used directly for their physical or diluent properties. Examples are:lubricants, paraffin waxes, bitumen, and white spirits and mineral turpentine (as solvent).

29
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32
33

Within the Guidelines this term refers to the use of fossil fuels as Feedstock, Reductant or Non-energy products.
However, the use of this term differs between countries and sources of energy statistics. In most energy statistics,
e.g., of the International Energy Agency (IEA), fuel inputs of reductants to blast furnaces are not included but
accounted for as inputs to a fuel conversion activity transforming coke and other inputs to blast furnace gas.

34
35
36
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Lime production occurring at facilities where the primary purpose is the production of lime as an intermediate
input: such as plants that produce steel, synthetic soda ash, calcium carbide, magnesia and magnesium metal, as
well as copper smelter and sugar mills. The lime produced by these facilities is often used on site and thus is often
not reported in national statistics. Also referred to as in-house lime production.

39
40
41
42
43
44

A class of emissions which includes a wide range of specific organic chemical substances. Non-Methane Volatile
Organic Compounds (NMVOCs) play a major role in the formation of ozone in the troposphere (lower atmosphere).
Ozone in the troposphere is a greenhouse gas. It is also a major local and regional air pollutant, causing significant
health and environmental damage. Because they contribute to ozone formation, NMVOCs are considered"precursor" greenhouse gases. NMVOCs, once oxidized in the atmosphere, produce carbon dioxide.

45
46
47

The normal (or Gaussian) distribution has the PDF given in the following equation and is defined by two
parameters (the mean µ and the standard σ deviation).

Model

Monte Carlo method

Non-energy products
Non-energy use

Non-marketed lime production

Non-Methane Volatile Organic Compounds (NMVOCs)

Normal distribution

1−( x − µ )2
2σ 2

, for - ∞ ≤ x ≤ ∞ .

48

f ( x) =49

Nutrient loading

σ 2π

e

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An increase in levels of nitrogen, phosphorus, and sulfur entering aquatic systems as a result of human activity
occurring in the catchment.

3

Observational data

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Observational data is empirical data from instrumental (usually monitoring equipment) or manual methods(through counts in a survey or census).

7
8
9
10

The exhaust gas from a chemical process (combustion or non-combustion). The off gas may be vented to theatmosphere, burned for energy recovery or flared (without energy recovery), or used as a feedstock for anotherchemical process. Secondary products may also be recovered from the off gas.

11
12
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16

The combustion of unwanted combustible materials such as paper, wood, plastics, textiles, rubber, and other debris
in the open or at an open dump site, where smoke and other emissions are released directly into the air without
passing through a chimney or stack. Open burning can also include incineration devices that do not control the
combustion air to maintain an adequate temperature and do not provide sufficient residence time for complete
combustion.

17
18

Water discharged from a dam.

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21

The area where water is discharged immediate downstream of a dam. It is characterised by exceptionally highlevels of turbulence in the water (see degassing emissions) that directly result from the operation of the dam.

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Containing dissolved oxygen.

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Chemically transform of a substance by combining it with oxygen.

26
27
28

The region of high dissolved oxygen concentration change within the water column that separates oxic and anoxic
regions.

29
30
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32
33

A compound that contributes to stratospheric ozone depletion. Ozone-depleting substances (ODS) include CFCs,
HCFCs, halons, methyl bromide, carbon tetrachloride, and methyl chloroform. ODS are generally very stable in
the troposphere and only degrade under intense ultraviolet light in the stratosphere. When they break down, they
release chlorine or bromine atoms, which then deplete ozone.

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35

Area covered with grass or other plants used or suitable for the grazing of livestock; grassland.

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See Probability density function.

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Soft, porous or compressed, sedimentary deposit of plant origin with high water content in the natural state (up to
about 90 percent). Countries may define peat according to their national circumstances.

41
42
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44

Peatlands are wetland ecosystems where net primary production exceeds organic matter decomposition as a resultof waterlogged, cold and acidic conditions, leading into accumulation of peat. They cover ~3% of the Earth’s
surface and contain about one-third of the global organic soil C.

45

Percentile

Off-gasOpen burning of waste

Outflow

Outflow area
Oxic

Oxidation
Oxycline

Ozone-depleting substances (ODS)

PasturePDF

PeatPeatland

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The kth percentile or population percentile is a value which separates the lowest kth part of the integral of theprobability density function (PDF) – i.e., an integral of a PDF tail from the kth percentile towards lower probability
densities.

4
5

The kth population percentile (0 ≤ k ≤ 100) of a population with a distribution function F(x) equals to z where z
satisfies F(z) = k/100

6
7

Sample kth percentile is an approximation for the population percentile which is derived from a sample. It is thevalue below which k percent of the observations lie.

8910Synthetically produced halocarbons containing only carbon and fluorine atoms. They are characterized by extreme
stability, non-flammability, low toxicity, zero ozone depleting potential, and high global warming potential.

1112

Perfluorocarbons (PFCs)
Plant-mediated emission

Vascular plants known to influence the production, transport and oxidation of methane in wetland soils

13

Polar/boreal

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15

Regions where mean annual temperature (MAT) is less than 0 oC.

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17

The water impounded behind a small dam (< 15 m high) or embankment.

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21

A reservoir. A component or components of the climate system where a greenhouse gas or a precursor of agreenhouse gas is stored. Examples of carbon pools are forest biomass, wood products, soils and the atmosphere.
The units are mass.

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23
24

The population is the totality of items under consideration. In the case of a random variable, the probability
distribution is considered to define the population of that variable.

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26

Precision is the inverse of uncertainty in the sense that the more precise something is, the less uncertain it is.

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Closeness of agreement between independent results of measurements obtained under stipulated conditions (seealso accuracy).

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Fuels which are extracted directly from natural resources. Examples are: crude oil, natural gas, coals, etc.

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33
34

Process-based models are based on a theoretical understanding of fundamental ecological, biological, chemical,
and physical processes. They provide a useful framework to project specific responses to altered environmental
conditions.

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37
38
39

A probability is a real number in the scale 0 to 1 attached to a random event. There are different ways in which
probability can be interpreted. One interpretation considers a probability as having the nature of a relative
frequency (i.e., the proportion of all outcomes corresponding to an event), whilst another interpretation regards a
probability as being a measure of degree of belief.

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41
42
43
44
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46

The Probability Density Function (PDF) describes the range and relative likelihood of possible values. The PDF
can be used to describe uncertainty in the estimate of a quantity that is a fixed constant whose value is not exactly
known, or it can be used to describe inherent variability. The purpose of the uncertainty analysis for the emission
inventory is to quantify uncertainty in the unknown fixed value of total emissions as well as emissions and activity
pertaining to specific categories. Thus, throughout these guidelines it is presumed that the PDF is used to estimate
uncertainty, and not variability, unless otherwise stated.

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Ponds

Pool/carbon pool

Population
PrecisionPrimary fuels

Process-based modelling

Probability

Probability density function

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Probability distribution

1
2
3

Statistical definition: A function giving the probability that a random variable takes any given value or belongs toa given set of values. The probability on the whole set of values of the random variable equals 1.

4
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Emissions from industrial processes involving chemical transformations other than combustion.

6
7
8

Process emissions

Pumped storage reservoirs

Pumped-storage reservoir are a way of storing energy store and generate energy by moving water
between two reservoirs at different elevations.

Quality Assurance

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Quality Assurance (QA) activities include a planned system of review procedures conducted by personnel not
directly involved in the inventory compilation/development process to verify that data quality objectives were met,
ensure that the inventory represents the best possible estimate of emissions and sinks given the current state ofscientific knowledge and data available, and support the effectiveness of the quality control (QC) programme.

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16

Quality Control (QC) is a system of routine technical activities, to measure and control the quality of the inventory
as it is being developed. The QC system is designed to:

Quality Control

17

(i)

Provide routine and consistent checks to ensure data integrity, correctness, and completeness;

18

(ii)

Identify and address errors and omissions;

19

(iii)

Document and archive inventory material and record all QC activities.

20
21
22
23

QC activities include general methods such as accuracy checks on data acquisition and calculations and the use of
approved standardised procedures for emission calculations, measurements, estimating uncertainties, archiving
information and reporting. More detailed QC activities include technical reviews of source categories, activity andemission factor data, and methods.

24
25
26
27

RAMSARThe Convention on Wetlands, called the Ramsar Convention, is an intergovernmental treaty that provides theframework for national action and international cooperation for the conservation and wise use of wetlands andtheir resources.

Removals

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Removal of greenhouse gases and/or their precursors from the atmosphere by a sink.

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The process of providing results of the inventory as described in volume 1 chapter 8.

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34

(1) A component or components of the climate system where a greenhouse gas or a precursor of a greenhouse gas
is stored. (UNFCCC Article 1.7)

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36
37

(2) Water bodies regulated for human activities (energy production, irrigation, navigation, recreation etc.) where
substantial changes in water area due to water level regulation may occur. The water impounded behind a
dam.

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Residence time

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44

Rice paddies

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River emissions

ReportingReservoir

The average amount of time that water spends in a particular system (lake, reservoir, etc). Defined as
the volume of the reservoir divided by the inflow.
A paddy field is a flooded parcel of arable land used for growing semiaquatic rice. Paddy cultivation
should not be confused with cultivation of deep water rice, which is grown in flooded conditions withwater more than 50 cm (20 in) deep for at least a month
These are GHG emissions from the surface of a normally (in a hydraulic sense) flowing river
downstream of the exceptionally turbulent region (see outflow area) immediately downstream of the

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dam. ‘Normal flow’ refers to the velocity of the flow being solely determined by channel shape andbed slope so that water column turbulence is produced predominantly by natural shear forces at thewater-river bed interface.

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6
7

Run-of-the-river reservoirs

Run-of-the-river hydroelectric systems are hydroelectric reservoir systems that harvest the energy
from flowing water to generate electricity. A run-of-the-river reservoir cannot store more water than
one day's annual mean inflow.

Secondary fuels

89

Fuels manufactured from primary fuels. Examples are: cokes, motor gasoline and coke oven gas, blast furnace gas.

1011

The process of storing carbon in a carbon pool.

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13
14

Any process, activity or mechanism which removes a greenhouse gas, an aerosol, or a precursor of a greenhousegas from the atmosphere. (UNFCCC Article 1.8) Notation in the final stages of reporting is the negative (-) sign.

15
16
17
18

Each of the different carbon pools decomposes, or turns over, at a different rate and is involved in different soil
processes, These are expressed as : fast (Active Pool or 0,5 yr turnover time), intermediate (Slow Pool or 20 to 40
yrs of turnover) and long turnover times (Passive Pool or 200 to 1500 yrs)

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21

Any process or activity which releases a greenhouse gas, an aerosol or a precursor of a greenhouse gas into theatmosphere. (UNFCCC Article 1.9) Notation in the final stages of reporting is the positive (+) sign.

22
23
24

Unregulated discharge from a reservoir that occurs when a reservoir is full and inflow to the reservoir exceeds theregulated outflow causing the water to pass over/through the dam's spillway.

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28

An engineered channel used to pass high flows safely past a dam when the reservoir water level is high than the
crest of the dam. Note that the maximum water level of a reservoir is frequently higher than the crest because of
the use of gates that are on top of the crest.

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The population standard deviation is the positive square root of the variance. It is estimated by the sample standard
deviation that is the positive square root of the sample variance.

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34
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38

Storage volume refers to the volume of water stored in a water body. The ‘active’ storage of a reservoir is thevolume of water contained between the spillway crest and the lowest outlet level. The ‘dead’ storage is the volume
of water that is below the lowest outlet and therefore cannot be routinely accessed for beneficial use. The ‘flood
control’ storage is the volume of water contained between the spillway crest and the top of gates (or otheradjustable structures) located on top of the spillway and used to regulate the discharge of floodwaters. The totalreservoir storage volume is the sum of dead storage, active storage, and flood control storage capacities.

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41
42

Surrogate data is data that is used in place of the actual data, where the specific data needed is unobtainable. Often
surrogate data is needed to describe changes in an emission source over time, for example population change may
be used to approximate change in waste arisings.

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46

Survey data is derived from random sampling of a population and does not include real data for the whole
population, e.g., the number of animals in a country or region by surveying a discrete selection of farms and groupsof farms in a country or region, or using more general surrogate data and assumptions.

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Systematic and random errors

Sequestration
Sink

Soil carbon pool

SourceSpill

SpillwayStandard deviation
Storage volume

Surrogate data

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Systematic error (i.e., bias) is the difference between the true, but usually unknown, value of a quantity being
estimated, and the mean observed value as would be estimated by the sample mean of an infinite set of observations.
The random error of an individual measurement is the difference between an individual measurement and theabove limiting value of the sample mean.

5
6

See systematic and random errors.

7
8

Areas where mean annual temperature (MAT) is between 0 – 10 oC.

910Areas where mean annual temperature (MAT) is between 10 – 20 oC.

11
12
13
14

The thin boundary layer model expresses the flux of gas across an air-water interface as the product of a gas
transfer velocity and the concentration change across the interface. It was originally developed by Liss and Slater(1974).

15
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17

A time series is series of values which are affected by random processes and which are observed at successive(usually equidistant) points in time.

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19
20
21

Transparency means that the assumptions and methodologies used for an inventory should be clearly explained tofacilitate replication and assessment of the inventory by users of the reported information. The transparency of
inventories is fundamental to the success of the process for the communication and consideration of information.

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23
24
25
26

The trend of a quantity measures its change over a time period, with a positive trend value indicating growth in
the quantity, and a negative value indicating a decrease. It is defined as the ratio of the change in the quantity over
the time period, divided by the initial value of the quantity, and is usually expressed either as a percentage or afraction.

Systematic error
Temperate, cold

Temperate, warm

Thin boundary layer modelTime series

Transparency

Trend

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29
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31

Trophic state32
33

Lakes or reservoirs are usually classified as being in one of fouroligotrophic, mesotrophic, eutrophic, or hypereutrophic. (see e.g., Carlson, 1977)

34
35

Oligotrophic: an oligotrophic lake or reservoir is characterised by low primary productivity, as a result of
low nutrient content. (Chl-a ≤ 2.6 µg L-1.)

36
37

Mesotrophic : mesotrophic lakes or reservoirs are characterised with an intermediate level of productivity (2.6 µg
L-1 < Chl-a ≤ 20 µg L-1.)

38
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Eutrophic : a eutrophic lake, pond or reservoir with high biological productivity. Due to excessive nutrients,
especially nitrogen and phosphorus, these water bodies are able to support an abundance of aquatic plants. (20 µg
L-1 < Chl-a ≤ 56 µg L-1.)

41
42

Hypereutrophic: a hypereutrophic body of water experiences the highest levels of biological productivity. (56 µg
L-1 < Chl-a)

43
44

Areas where mean annual temperature (MAT) is more than 20 oC.

45
46
47
48
49

An unbiased estimator is a statistic whose expected value equals the value of the parameter being estimated. Notethat this term has a specific statistical meaning and that an estimate of a quantity calculated from an unbiased
estimator may lack bias in the statistical sense, but may be biased in the more general sense of the word if thesample has been affected by unknown systematic error. Thus, in statistical usage, a biased estimator can be

The trophic state is a measure of the biological productivity of a water body. It is usually characterized by somecombination of nutrients, photosynthetic pigments (Chl-a) and/or water column optical properties. As the ambientnutrient levels increase, primary production (the algal population) increases and the water clarity decreases. As
primary production increases, higher levels of biological production are supported and the trophic state increases.
possible

trophic

states:Tropical

Unbiased estimator

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understood as a deficiency in the statistical evaluation of the collected data, and not in the data themselves or in
the method of their measurement or collection. For example, the arithmetic mean (average) x is an unbiased
estimator of the expected value (mean).

4
5
6
7
8

Lack of knowledge of the true value of a variable that can be described as a probability density function
characterizing the range and likelihood of possible values. Uncertainty depends on the analyst’s state of knowledge,
which in turn depends on the quality and quantity of applicable data as well as knowledge of underlying processes
and inference methods. (See Volume 1 Chapter 3.)

9
10
11

An uncertainty analysis of a model aims to provide quantitative measures of the uncertainty of output values caused
by uncertainties in the model itself and in its input values, and to examine the relative importance of these factors.

12
13
14
15
16

Validation is the establishment of sound approach and foundation. In the context of emission inventories,
validation involves checking to ensure that the inventory has been compiled correctly in line with reporting
instructions and guidelines. It checks the internal consistency of the inventory. The legal use of validation is to
give an official confirmation or approval of an act or product.

17
18
19
20
21

This refers to observed differences attributable to true heterogeneity or diversity in a population. Variability derives
from processes which are either inherently random or whose nature and effects are influential but unknown.
Variability is not usually reducible by further measurement or study, but can be characterised by quantities suchas the sample variance.

22
23
24
25

Verification refers to the collection of activities and procedures that can be followed during the planning anddevelopment, or after completion of an inventory that can help to establish its reliability for the intended
applications of that inventory.

26
27
28

Typically, methods external to the inventory are used to check the truth of the inventory, including comparisonswith estimates made by other bodies or with emission and uptake measurements determined from atmosphericconcentrations or concentration gradients of these gases.

29
30

A watercourse is the channel that a flowing body of water follows.

31
32
33
34

A wetland is a land area that is saturated with water, either permanently or seasonally, such that it takes on thecharacteristics of a distinct ecosystem. The primary factor that distinguishes wetlands from other land forms or
water bodies is the characteristic vegetation of aquatic plants, adapted to the hydric soils.

35
36
37
38
39

The controlled release of water from a dam. Depending on the dam’s design, i.e. the number and level of discrete
outlets, the withdrawn water may originate solely from specific regions of the water column, i.e. epilimnion,
metalimnion and hypolimnion. The withdrawal region for a specific discharge depends strongly on the density
stratification of the water body, the outlet dimensions, and the reservoir morphology.

Uncertainty

Uncertainty analysis
Validation

Variability

Verification

Watercourse
WetlandWithdrawal