Definitions - r

Rapid growth and occupation through early reproduction, short life spans, low biomass, and lots of offspring. See K-Selection.

The R value or R-value is a measure of thermal resistance used in the building and construction industry. The bigger the number, the better the building insulation's effectiveness. R value is the reciprocal of U-value. Often used as a measure of bulk insulation products, such as a roof insulation Batts.

Original Wikipedia entry

A device designed to reduce or stop the flow of radiant energy.

A heating system that warms the floor, which radiates heat to the whole house. Often either electrical or hot water based.

An increase in temperature with height due to radiational cooling of the earth's surface. Also called a nocturnal inversion.

Global warming is the name given to the theory that there is increase in the average temperature of the Earth surface air and oceans since the mid-20th century and its projected continuation.

The exact mechanism of warming is not precisely understood, although it is strongly suspected that Greenhouse gases are to blame, as increasing concentrations of such gases help trap heat in the atmosphere and so raise mean temperatures.

Wikipedia Entry

An area of diminished precipitation on the lee (downwind) side of a mountain or mountain range.

Rainwater harvesting refers to the act of 'keeping' rainwater that falls on your roof for use later. This implies that the a certain amount of plumbing is done to collect the water to a central tank, then plumbing is done to provide the water where needed. Also overflow plumbing needs to be done for when the tank is full.

This is often done to reduce a building's dependence on piped 'town water' or to provide fresh water where town water is not available. The water so collected is suitable for drinking as long the roof is clean and the water tank is rated for potable water storage.

See here for an online calculator to work out the amount of water you can harvest and the size of tank you need in relation to your water usage.

Rapidly renewable materials include those that replenish faster than hardwoods. Bamboo and cork fall into this category.

Reused heat or energy that otherwise would be lost. For example, a combined cycle power plant recaptures some of its own waste heat and reuses it to make extra electric power.

Fragments of products or finished products of a manufacturing process, which has converted a resource into a commodity of real economic value, and includes pre-consumer and post-consumer material but does not include excess resources of the manufacturing process.

Air pollution occurs when the air contains gases, dust, fumes or odour in harmful amounts. That is, amounts which could be harmful to the health or comfort of humans and animals or which could cause damage to plants and materials.

The substances that cause air pollution are called pollutants. Pollutants that are pumped into our atmosphere and directly pollute the air are called primary pollutants. Primary pollutant examples include carbon monoxide from car exhausts and sulfur dioxide from the combustion of coal.

Further pollution can arise if primary pollutants in the atmosphere undergo chemical reactions. The resulting compounds are called secondary pollutants. Photochemical smog is an example of this.

The redox (reduction–oxidation) cell is a reversible cell in which electrochemical components are dissolved in the electrolyte. Redox flow batteries are rechargeable.

Total dry weight of all living organisms that can be supported at each tropic level in a food chain.

A product that has been completely disassembled and restored to its original working order while maximizing the reuse of its original materials.

Ability of an ecosystem to maintain relative ecological integrity indefinitely.

The release of a substance (usually a gas when referring to the subject of climate change) into the atmosphere.

Any product diverted from the supply of discarded materials by refurbishing and marketing said product without substantial change to its original form.

Substance, especially man-made, that pollutes or contaminates an environment.

Fish species that complete their entire life cycle in freshwater. Non-anadromous fish. An example is rainbow trout.

Sustainable development is the act of development (as in industrial development, be it farming, manufacturing, commerce, etc) performed in such a way it is:

• Green,
• Clean,
• Sustainable, and,
• Balanced

A practice in which the primary consideration of material use begins with the concept of "Reduce - Reuse - Recycle - Repair" stated in descending order of priority.

This concept may be applied in everyday life to help promote a sustainable society. In design, begin by reducing the amount of material that is specified; find ways to reuse materials, recycle products or product waste; specify products made from recycled materials; and repair or restore products instead of replacing them.

The heating of oil shale to get the oil out from it.

A form of outdoor advertising with a clean is green message.Essentially it is created by power washing a message into a dirty surface such as a side-walk or an outdoor concrete wall. A specific form of green graffiti.

How legal such graffiti is depends on the laws in force for the area concerned. Some local governments require any form of advertising to require prior permission before placement. Also careful consideration needs to be given to the effect of power cleaning on the actual material being cleaned, it could well promote breaking down the exposed surface quicker than would have otherwise being the case.

Rewilding is the act of reintroducing species to areas where they previously went extinct. The assumption being that by them being reintroduced it makes the areas more 'wild' and therefore natural compared to what it was previously.

An area of land directly influenced by water. An ecosystem that is transitional between land and water ecosystems. Riparian areas usually have visible vegetative or physical characteristics reflecting the influence of water. River sides, lake borders, and marshes are typical riparian areas.

Riparian areas that are managed to protect the aquatic and riparian ecosystem. A riparian buffer protects water quality and temperature, habitat along the banks, upland habitat for aquatic and riparian species, and some or all of the floodplain.

The rights of water use possessed by a person owning land containing or bordering a water course or lake.

A rotating, cigar-shaped cloud that sometimes precedes a thunderstorm. Often seen in UFO photographs.

Fish not prized for sport or eating, such as gar and suckers. Most are more tolerant of changing environmental conditions than are game or food species.