The language of Green can be confusing at the best of times.  Between carbon offsetting, Kyoto Protocols and post-consumer waste, it can be easy to feel lost by the myriad of eco-terminology.

We hope that our A-Z of green will make things a little easier...

Alternative Energy
Any energy source that doesn’t come from the fossil fuel sources of oil, natural gas and coal. See also renewable energy.

Biodegradable
Any waste material that is made up of naturally occurring parts, can be decomposed by bacteria or fungi and will be absorbed back into the ecosystem. For example, food waste is biodegradable, while plastic is not.

Biofuel
This is a term used to describe a type of fuel made from biomass, (any living or recently dead biological material).  Most commonly, this means that plant matter (such as corn, soybeans, flaxseed, rapeseed, sugar cane or palm oil) is used to produce the fuel, but animal matter (such as cow dung) can also be used. Biofuels are used to ensure power supply and reduce the greenhouse effect, although they are usually thought of as being less carbon neutral than other forms of renewable energy.

Carbon Balancing
Often confused with carbon offsetting, but generally more concerned with reducing personal carbon levels, rather than compensating for them. Carbon balancing sometimes refers to a new technology that will reduce overall greenhouse emissions.

Carbon Calculator
A tool to help you to work out the size of your carbon footprint.

Carbon Dioxide
Also referred to as 'carbon' and 'CO2'.
A compound that we tend to think of as being the main greenhouse gas. Carbon dioxide exists naturally in the earth’s atmosphere but, due to its ability to absorb some infrared wavelengths of sunlight and the fact is stays in the atmosphere for a long time, is an important factor in global warming. It is thought that CO2 contributes up to 12% to the greenhouse effect.

Carbon Footprint
A measurement of how much CO2 is released into the atmosphere as a result of your everyday lifestyle. A carbon footprint is generally expressed in tons of CO2 and takes into account the way you travel, what you eat and how much energy you use in your home. Average national carbon footprints vary greatly, from 0.04 tonnes in Cambodia to a whopping 19.8 tonnes in America. The average British footprint is 9.4 tonnes.

Carbon Neutral
Carbon neutrality is a term generally used when a certain amount of carbon is offset by payment or by giving up other carbon-producing activities. For example, a flight from Edinburgh to Southampton produces 0.12 tonnes of CO2 per person, which can be offset by paying £5. Once this payment is made, the flight can then be referred to as carbon neutral for that individual.

Carbon Offsetting
This is a term that refers to reducing carbon levels somewhere else in the world to compensate for your own CO2 emissions. A common example of offsetting is paying a company to plant trees to counterbalance the emissions produced by your air travel. However, some critics believe that paying for individual ‘eco-sins’ is the wrong way to reduce overall CO2 emissions and may even help to legitimize the continued production of greenhouse gases.

Carbon Trading
This is an administrative approach to controlling carbon and one that provides financial incentives for lowering pollution levels. The system works by putting a cap on the total emissions levels for a particular country, and then giving various business tradable carbon credits that relate to the amount of CO2 they are allowed to emit. Businesses can then buy and sell these credits as they expect to fail or meet their emissions target. This system also allows corporations to retire their carbon credits in return for a tax deduction. Over time, the amount of carbon credits available will be lowered, therefore reducing the amount of emissions in the environment.

Climate
This refers to averages and variations in weather and temperature over a particular timeframe. Climate can refer to the whole planet, a continent or a particular country.

Climate Change
Terminology most commonly associated with global warming in modern times, but can also refer to global cooling as well. The term describes the overall changes in the Earth’s climate, whether looking at millions of years or just a few decades. These changes can be due to internal Earth processes, external forces (such as solar variation) or, in more recent times, human activity.

Composting
The process of breaking down biodegradable waste into mulch or compost to be used on a garden.

Fossil Fuels
Any type of fuel that is made from the fossilised remains of dead animals and plants. This includes oil, natural gas and coal, which are also commonly referred to non-renewable natural resources.

Global Cooling
Makes up part of climate change terminology and generally refers to an overall cooling of the Earth's surface and atmosphere. Is most often used in reference to ice age cycles and will not usually play a large part in the overall topic of going green.

Global Warming
This term applies to the warming of the Earth’s atmosphere and generally implies that human influence is to blame for the increase in temperature. Looking at global warming will often include a projection of future temperature increases.

Greenhouse Effect
This process was first discovered in 1829 by Joseph Fourier and the term is used to describe the warming of the Earth’s surface by infrared radiation. It is thought that the earth would be 20-30 C cooler without the greenhouse effect. However, in more recent years, the greenhouse effect has been associated with the over-warming of the Earth’s surface. This has been caused by the large amounts of greenhouse gas that we have pumped into the environment. In turn, the build-up of these gases has stopped heat from escaping our atmosphere, as well as reflecting infrared radiation back down to the Earth’s surface. This build-up of heat is what causes the affects we link to global warming.

Greenhouse Gas
This is a general term for any components in our atmosphere that lead to the greenhouse effect. Greenhouse gases include water vapour, CO2, methane, nitrous oxide, and ozone. Some of these gases occur naturally, while others are the result of human activity.

Hybrid Car
A hybrid vehicle combines a conventional engine with an on-board energy storage system. This secondary motor tends to be electric and gains its charge by capturing the kinetic energy produced during braking. This engine combination allows the vehicle to achieve a greater fuel economy without having the limited mileage range of a fully electric car.

Intergovernmental Panel on Climate Change (IPCC)
The IPCC was established in 1988 by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP). The job of the IPCC is to evaluate the risk of human-induced climate change by considering all the available scientific and technical literature. The IPCC does not carry out research or directly monitor climate change.

Kyoto Protocol
Although the Kyoto Protocol is often spoken of as a separate piece of legislation, it is actually an amendment to the international treaty on climate change. The Kyoto agreement states that the signatory nations will abide by limitations on the amount of greenhouse gases they can produce. The protocol currently covers over 160 countries, with America and Australia being notable exceptions. Other countries, such as India and China, have ratified the protocol but are not required to reduce their carbon emissions under the present agreement. The Kyoto Protocol will come to an end in 2012, at which point a new agreement will be made.

Landfill
This is a site where waste materials are buried in the ground as a form of disposal. Landfills are sometime referred to as the ‘dump’ or ‘tip’.

Natural Resources
This is a term given to any naturally occurring product that is useful and/or valuable in its unaltered state. Mining, oil extraction, fishing, hunting, and forestry are generally considered natural-resource industries. Natural resources are generally grouped into renewable, flow renewable and non-renewable.

Post-Consumer
A term most commonly applied to recycled paper products, such as toilet roll, packaging and newspapers. Products made of ‘post-consumer waste’ mean that the material has completed its life as a consumer item and has been discarded. This can then be reused and recycled back into functional, useful products.

Pre-Consumer
This is material that has been discarded by the manufacturing industry before even reaching a consumer. It includes trimmings from paper production and defective aluminium cans. Although this isn’t commonly thought of as recycling, both of these products can be reintroduced into the production process to decrease wasted output.

Recycled
Recycled products are made from manufactured materials that have been reclaimed and reprocessed to create new products. Paper, glass, aluminium and wood are among the most commonly recycled materials.

Renewable Energy
Energy generated by renewable sources means that the supply is regenerative or unlikely to be depleted. This covers energy production from wind, solar and tidal power. Renewable energy sources currently account for 14% of the world’s energy consumption and, due to the fact they produce little to no greenhouse gases, this figure is likely to rise in the future.

Sustainable Living
This is a lifestyle that can be sustained without exhausting any natural resources. It can be applied to individuals or whole societies. The philosophy behind sustainable living is a series of life choices favouring sustainability, such as decisions about transport, diet or accommodation.

Sustainably Harvested
Generally used in reference to wood, although can also apply to any plant material. Sustainably harvested products have been grown in a well-managed forest that is governed by the criteria of established wood certifiers, such as the Forest Stewardship Council.