Glossary of Environmental Science - L

L

• land use, Land-use change and forestry (LULUCF) - land uses and land-use changes can act either as sinks or as emission sources. It is estimated that approximately one-fifth of global emissions result from LULUCF activities. The Kyoto Protocol allows parties to receive emissions credit for certain LULUCF activities that reduce net emissions.
• landfill- solid waste disposal in which refuse is buried between layers of soil, a method often used to reclaim low-lying ground; the word is sometimes used as a noun to refer to the waste itself.
• landfill gas – the gas emissions from biodegrading waste in landfill, including CO₂, CH4, and small amounts of nitrogen, oxygen with traces of toluene, benzene and vinyl chloride.
• landfill levy - levy applied at differential rates to municipal, commercial and industrial and prescribed wastes disposed to licensed landfills the levies used to foster the environmentally sustainable use of resources and best practice in waste management.
• landfill prohibition - The banning of a certain material or product type from disposal to landfills. Occurs occasionally, for example, where a preferable waste management option is available.
• landfill (dump or tip and historically as a midden) - a site for the disposal of waste materials by burial and is the oldest form of waste treatment.
• land use planning - a branch of public policy which encompasses various disciplines which seek to order and regulate the use of land in an efficient and ethical way.
• leaching – the movement of chemical in the upper layers of soil into lower layers or into groundwater by being dissolved in water.
• lithosphere - the solid outermost shell of a rocky planet.

considered ideal for gardening and agricultural uses.

• leachate (waste) - the mixture of water and dissolved solids (possibly toxic) that accumulates as water passes through waste and collects at the bottom of a landfill site.
• leaf area index (LAI) – the ratio of photosynthetic leaf area to ground area covered (optimal for photosynthesis = 3-5) . LAI is often optimised by shifts in leaf angle, a form of solar tracking.
• 'level (scale, context or framework) – a context, frame of reference or degree of organisation within an integrated system. A level may or may not be spatially delimited.
• life cycle (of a product) - All stages of a product's development, from raw materials, manufacturing through to consumption and ultimate disposal.
• Life Cycle Analysis (LCA) - an objective process to evaluate the environmental impacts associated with a product, process, or activity. A means of identifying resource use and waste released to the environment, and to assess management options.
• life support systems - according to the World Conservation Union (IUCN), the biophysical processes "that sustain the productivity, adaptability and capacity for renewal of lands, waters, and / or the biosphere as a whole."
• lilacwater – recycled water that is unsuitable for drinking.
• linear low density polyethylene - a member of the polyolefin family of plastics. It is a strong and flexible plastic and usually used in film for packaging, bags and for industrial products such as pressure pipe.
• linear metabolism - direct conversion of resources into wastes that are often sent directly to landfill
• loam - a soil composed of sand, silt, and clay in relatively even concentration (about 40-40-20% concentration respectively), *locally existing capacity - the total ecological production that is found within a country’s territories. It is usually expressed in hectares based on world average productivity.
• low density polyethylene - A member of the polyolefin family of plastics. It is a flexible material and usually used as film for packaging or as bags.
• low entropy energy - to high-quality energy, or energy that is concentrated and available. Electricity is considered the energy carrier with the lowest entropy (i.e. highest quality) as it can be transformed into mechanical energy at efficiency rates well above 90%. In contrast, fossil fuel chemical energy can only be converted into mechanical energy at a typical efficiency rate of 25% (cars) to 50 percent (modern power plants). The chemical energy of biomass is of lower quality.