Editing IPCC:AR6/Data/Glossary (section)

== L ==

<div class="glossary-entry">
<div id="Land"></div>
=== <span class="glossary-term">Land</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI; WGII; WGIII</div>

<div class="glossary-definition">'''Definition:''' The terrestrial portion of the biosphere that comprises the natural resources (soil, near-surface air, vegetation and other biota, and water), the ecological processes, topography, and human settlements and infrastructure that operate within that system (FAO, 2007; UNCCD, 1994).</div>
</div>

<div class="glossary-entry">
<div id="Land_cover"></div>
=== <span class="glossary-term">Land cover</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI; WGII; WGIII</div>

<div class="glossary-definition">'''Definition:''' The biophysical coverage of land (e.g., bare soil, rocks, forests, buildings and roads or lakes). Land cover is often categorised in broad land-cover classes (e.g., deciduous forest, coniferous forest, mixed forest, grassland bare ground). [Note: In some literature, land cover and land use are used interchangeably, but the two represent distinct classification systems. For example, the land cover class woodland can be under various land uses such as livestock grazing, recreation, conservation, or wood harvest.]</div>
</div>

<div class="glossary-entry">
<div id="Land-cover_change"></div>
=== <span class="glossary-term">Land-cover change</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI; WGII; WGIII</div>

<div class="glossary-definition">'''Definition:''' Change from one land cover class to another, due to change in land use or change in natural conditions (Pongratz et al., 2018).</div>
</div>

<div class="glossary-entry">
<div id="Land_degradation"></div>
=== <span class="glossary-term">Land degradation</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGII; WGIII</div>

<div class="glossary-definition">'''Definition:''' A negative trend in land condition, caused by direct or indirect human-induced processes including anthropogenic climate change, expressed as a long-term reduction or loss of at least one of the following: biological productivity, ecological integrity or value to humans. [Note: This definition applies to forest and non-forest land. Changes in land condition resulting solely from natural processes (such as volcanic eruptions) are not considered to be land degradation. Reduction of biological productivity or ecological integrity or value to humans can constitute degradation, but any one of these changes need not necessarily be considered degradation.]</div>
</div>

<div class="glossary-entry">
<div id="Land_degradation_neutrality"></div>
=== <span class="glossary-term">Land degradation neutrality</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGIII</div>

<div class="glossary-definition">'''Definition:''' A state whereby the amount and quality of land resources necessary to support ecosystem functions and services and enhance food security remain stable or increase within specified temporal and spatial scales and ecosystems (UNCCD, 2020).</div>
</div>

<div class="glossary-entry">
<div id="Land_management"></div>
=== <span class="glossary-term">Land management</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGII; WGIII</div>

<div class="glossary-definition">'''Definition:''' The sum of land-use practices (e.g., sowing, fertilising, weeding, harvesting, thinning and clear-cutting) that take place within broader land-use categories (Pongratz et al., 2018).</div>
</div>

<div class="glossary-entry">
<div id="Land_management_change"></div>
=== <span class="glossary-term">Land management change</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGIII</div>

<div class="glossary-definition">'''Definition:''' A change in land management that occurs within a land-use category.</div>
</div>

<div class="glossary-entry">
<div id="Land_potential"></div>
=== <span class="glossary-term">Land potential</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGIII</div>

<div class="glossary-definition">'''Definition:''' The inherent, long-term potential of the land to sustainably generate ecosystem services, which reflects the capacity and resilience of the land-based natural capital, in the face of ongoing environmental change (UNEP, 2016).</div>
</div>

<div class="glossary-entry">
<div id="Land_rehabilitation"></div>
=== <span class="glossary-term">Land rehabilitation</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGIII</div>

<div class="glossary-definition">'''Definition:''' Direct or indirect actions undertaken with the aim of reinstating a level of ecosystem functionality, where the goal is provision of goods and services rather than ecological restoration (McDonald et al., 2016).</div>
</div>

<div class="glossary-entry">
<div id="Land_restoration"></div>
=== <span class="glossary-term">Land restoration</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGIII</div>

<div class="glossary-definition">'''Definition:''' The process of assisting the recovery of land from a degraded state (IPBES, 2018; McDonald et al. 2016).</div>
</div>

<div class="glossary-entry">
<div id="Land_surface_air_temperature"></div>
=== <span class="glossary-term">Land surface air temperature</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI</div>

<div class="glossary-longer-term">'''Full term:''' Land surface air temperature (LSAT)</div>

<div class="glossary-definition">'''Definition:''' The near-surface air temperature over land, typically measured at 1.25–2 m above the ground using standard meteorological equipment.</div>
</div>

<div class="glossary-entry">
<div id="Land_use"></div>
=== <span class="glossary-term">Land use</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI; WGII; WGIII</div>

<div class="glossary-definition">'''Definition:''' The total of arrangements, activities and inputs applied to a parcel of land. The term land use is also used in the sense of the social and economic purposes for which land is managed (e.g., grazing, timber extraction, conservation and city dwelling). In national greenhouse gas (GHG) inventories, land use is classified according to the IPCC land-use categories of forest land, cropland, grassland, wetlands, settlements and other lands (see the 2006 IPCC Guidelines for National GHG Inventories and their 2019 Refinement for details (IPCC, 2006, 2019)).</div>
</div>

<div class="glossary-entry">
<div id="Land_use,_land-use_change_and_forestry"></div>
=== <span class="glossary-term">Land use, land-use change and forestry</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGIII</div>

<div class="glossary-longer-term">'''Full term:''' Land use, land-use change and forestry (LULUCF)</div>

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

<div class="glossary-entry">
<div id="Land-use_change"></div>
=== <span class="glossary-term">Land-use change</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI; WGII; WGIII</div>

<div class="glossary-longer-term">'''Full term:''' Land-use change (LUC)</div>

<div class="glossary-definition">'''Definition:''' The change from one land use category to another. Note that in some scientific literature, land-use change encompasses changes in land-use categories as well as changes in land management.</div>
</div>

<div class="glossary-entry">
<div id="Land_water_storage"></div>
=== <span class="glossary-term">Land water storage</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI</div>

<div class="glossary-longer-term">'''Full term:''' Land water storage (LWS)</div>

<div class="glossary-definition">'''Definition:''' Land water storage (LWS) includes all surface water, soil moisture, groundwater storage and snow, but excludes water stored in glaciers and ice sheets. Changes in LWS can be caused either by direct human intervention in the water cycle (e.g., storage of water in reservoirs by building dams in rivers, groundwater extraction from groundwater reservoirs for consumption and irrigation, or deforestation) or by climate variations (e.g., changes in the amount of water in endorheic lakes and wetlands, the canopy, the soil, the permafrost and the snowpack). Land water storage changes caused by climate variations may also be indirectly affected by anthropogenic influences.</div>
</div>

<div class="glossary-entry">
<div id="Lapse_rate"></div>
=== <span class="glossary-term">Lapse rate</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI</div>

<div class="glossary-definition">'''Definition:''' The rate of change of an atmospheric variable, usually temperature, with height. The lapse rate is considered positive when the variable decreases with height.</div>
</div>

<div class="glossary-entry">
<div id="Large-scale"></div>
=== <span class="glossary-term">Large-scale</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI</div>

<div class="glossary-definition">'''Definition:''' The climate system involves process interactions from the micro- to the global-scale. Any threshold for defining ‘large-scale’ is arbitrary. Understanding of large-scale climate variability and change requires knowledge of both the response to external forcings and the role of internal variability. Many external forcings have substantial hemispheric or continental scale variations. Modes of climate variability are driven by ocean- basin-scale processes. Thus we define large-scale to include ocean-basin and continental scales as well as hemispheric and global scales.</div>
</div>

<div class="glossary-entry">
<div id="Last_millennium"></div>
=== <span class="glossary-term">Last millennium</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI</div>

<div class="glossary-definition">'''Definition:''' The interval of the Common Era (CE) between 1001 and 2000 CE. Encompasses the Little Ice Age, a roughly defined period characterized by multiple expansions of mountain glaciers worldwide, the timing of which differs among regions but generally occurred between 1400 CE and 1900 CE. The last millennium also mostly encompasses the Medieval Warm Period (also called the Medieval Climate Anomaly), a roughly defined period of relatively warm conditions or other climate excursions such as extensive drought, the timing and magnitude of which differ among regions, but generally occurred between 900 and 1400 CE. Transient climate model experiments by the Paleoclimate Modelling Intercomparison Project (PMIP) for the last millennium extend from 850–1849 CE.</div>
</div>

<div class="glossary-entry">
<div id="Latent_heat_flux"></div>
=== <span class="glossary-term">Latent heat flux</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI; WGIII</div>

<div class="glossary-definition">'''Definition:''' The turbulent flux of heat from the Earth’s surface to the atmosphere that is associated with evaporation or condensation of water vapour at the surface; a component of the surface energy budget.</div>
</div>

<div class="glossary-entry">
<div id="Leakage"></div>
=== <span class="glossary-term">Leakage</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGIII</div>

<div class="glossary-definition">'''Definition:''' The effects of policies that result in a displacement of the environmental impact, thereby counteracting the intended effects of the initial policies.</div>
</div>

<div class="glossary-entry">
<div id="Leapfrogging"></div>
=== <span class="glossary-term">Leapfrogging</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGIII</div>

<div class="glossary-definition">'''Definition:''' The ability of developing countries to bypass intermediate technologies and jump straight to advanced clean technologies.</div>
</div>

<div class="glossary-entry">
<div id="Least_Developed_Countries"></div>
=== <span class="glossary-term">Least Developed Countries</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGII</div>

<div class="glossary-longer-term">'''Full term:''' Least Developed Countries (LDCs)</div>

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

<div class="glossary-entry">
<div id="Lifecycle_assessment"></div>
=== <span class="glossary-term">Lifecycle assessment</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGIII</div>

<div class="glossary-longer-term">'''Full term:''' Lifecycle assessment (LCA)</div>

<div class="glossary-definition">'''Definition:''' Compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product or service throughout its lifecycle (ISO, 2018).</div>
</div>

<div class="glossary-entry">
<div id="Lifetime"></div>
=== <span class="glossary-term">Lifetime</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI</div>

<div class="glossary-definition">'''Definition:''' Lifetime is a general term used for various time scales characterizing the rate of processes affecting the concentration of trace gases. The following lifetimes may be distinguished:</div>
</div>

<div class="glossary-entry">
<div id="Light-absorbing_particles"></div>
=== <span class="glossary-term">Light-absorbing particles</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI</div>

<div class="glossary-definition">'''Definition:''' Light-absorbing particles (LAP), for example, black carbon (BC), brown carbon and dust, are particles that absorb solar radiation and convert it into internal energy, thus raising the particle’s temperature and emitting thermal-infrared radiation that is selectively absorbed by the surrounding medium. LAP affect the energy balance of the atmosphere and clouds, and when deposited on snow and ice, they reduce snow/ice albedo, increasing heating and accelerating melting. These particles have a warming effect on climate.</div>
</div>

<div class="glossary-entry">
<div id="Likelihood"></div>
=== <span class="glossary-term">Likelihood</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI; WGII; WGIII</div>

<div class="glossary-definition">'''Definition:''' The chance of a specific outcome occurring, where this might be estimated probabilistically. Likelihood is expressed in this report using a standard terminology (Mastrandrea et al., 2010).</div>
</div>

<div class="glossary-entry">
<div id="Lithosphere"></div>
=== <span class="glossary-term">Lithosphere</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI</div>

<div class="glossary-definition">'''Definition:''' The upper layer of the solid Earth, both continental and oceanic, which comprises all crustal rocks and the cold, mainly elastic part of the uppermost mantle. Volcanic activity, although part of the lithosphere, is not considered as part of the climate system, but acts as an external forcing factor.</div>
</div>

<div class="glossary-entry">
<div id="Livelihood"></div>
=== <span class="glossary-term">Livelihood</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI; WGII; WGIII</div>

<div class="glossary-definition">'''Definition:''' The resources used and the activities undertaken in order for people to live. Livelihoods are usually determined by the entitlements and assets to which people have access. Such assets can be categorised as human, social, natural, physical or financial.</div>
</div>

<div class="glossary-entry">
<div id="Local_extinction"></div>
=== <span class="glossary-term">Local extinction</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGII</div>

<div class="glossary-definition">'''Definition:''' See extirpation</div>
</div>

<div class="glossary-entry">
<div id="Local_knowledge"></div>
=== <span class="glossary-term">Local knowledge</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGII; WGIII</div>

<div class="glossary-longer-term">'''Full term:''' Local knowledge (LK)</div>

<div class="glossary-definition">'''Definition:''' The understandings and skills developed by individuals and populations, specific to the places where they live. Local knowledge informs decision-making about fundamental aspects of life, from day-to-day activities to longer-term actions. This knowledge is a key element of the social and cultural systems which influence observations of and responses to climate change; it also informs governance decisions (UNESCO, 2018).</div>
</div>

<div class="glossary-entry">
<div id="Local_sea_level_change"></div>
=== <span class="glossary-term">Local sea level change</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI</div>

<div class="glossary-definition">'''Definition:''' Change in sea level relative to a datum (such as present-day mean sea level) at spatial scales smaller than 10 km.</div>
</div>

<div class="glossary-entry">
<div id="Lock-in"></div>
=== <span class="glossary-term">Lock-in</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGII; WGIII</div>

<div class="glossary-definition">'''Definition:''' A situation in which the future development of a system, including infrastructure, technologies, investments, institutions and behavioural norms, is determined or constrained (‘locked in’) by historical developments.</div>
</div>

<div class="glossary-entry">
<div id="Long-lived_climate_forcers"></div>
=== <span class="glossary-term">Long-lived climate forcers</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGIII</div>

<div class="glossary-longer-term">'''Full term:''' Long-lived climate forcers (LLCFs)</div>

<div class="glossary-definition">'''Definition:''' [TERM NOT USED - Term name change to ''Long-lived greenhouse gases (LLGHGs) in WGI report] A set of well-mixed greenhouse gases with long atmospheric lifetimes. This set of compounds includes carbon dioxide (CO2) and nitrous oxide (N2O), together with some fluorinated gases. They have a warming effect on climate. These compounds accumulate in the atmosphere at decadal to centennial timescales, and their effect on climate hence persists for decades to centuries after their emission. On timescales of decades to a century already emitted emissions of long-lived climate forcers can only be abated by greenhouse gas removal (GGR).</div>
</div>

<div class="glossary-entry">
<div id="Long-lived_greenhouse_gases"></div>
=== <span class="glossary-term">Long-lived greenhouse gases</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI</div>

<div class="glossary-longer-term">'''Full term:''' Long-lived greenhouse gases (LLGHGs)</div>

<div class="glossary-definition">'''Definition:''' A set of well-mixed greenhouse gases with long atmospheric lifetimes. This set of compounds includes 2) carbon dioxide (CO and 2 O) nitrous oxide (N, together with some halogenated compounds. They have a warming effect on climate. These compounds accumulate in the atmosphere at decadal to centennial time scales, and their effect on climate hence persists for decades to centuries after their emission. On time scales of decades to a century, already emitted emissions of long-lived climate forcers can only be abated by greenhouse gas removal.</div>
</div>

<div class="glossary-entry">
<div id="Loss_and_Damage,_and_losses_and_damages"></div>
=== <span class="glossary-term">Loss and Damage, and losses and damages</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGII; WGIII</div>

<div class="glossary-definition">'''Definition:''' Research has taken Loss and Damage (capitalised letters) to refer to political debate under the United Nations Framework Convention on Climate Change (UNFCCC) following the establishment of the Warsaw International Mechanism for Loss and Damage in 2013, which is to ‘address loss and damage associated with impacts of climate change, including extreme events and slow onset events, in developing countries that are particularly vulnerable to the adverse effects of climate change.’ Lowercase letters (losses and damages) have been taken to refer broadly to harm from (observed) impacts and (projected) risks and can be economic or non-economic (Mechler et al., 2018).</div>
</div>

<div class="glossary-entry">
<div id="Low_Elevation_Coastal_Zones"></div>
=== <span class="glossary-term">Low Elevation Coastal Zones</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGII</div>

<div class="glossary-longer-term">'''Full term:''' Low Elevation Coastal Zones (LECZ)</div>

<div class="glossary-definition">'''Definition:''' Coastal areas below 10 m of elevation above sea level that are hydrologically connected to the sea.</div>
</div>

<div class="glossary-entry">
<div id="Low-likelihood,_high_impact_outcomes"></div>
=== <span class="glossary-term">Low-likelihood, high impact outcomes</span> ===

<div class="glossary-working-groups">'''Working Groups:''' WGI; WGII</div>

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

</div>
<div class="glossary-letter-section">