The term garbage generally refers to all domestic (household) waste that cannot be recycled or composted in an organics waste bin. 

Genetic engineering refers to the process of modifying the genetic information (DNA) of an organism.  This may involve the insertion or removal of genetic material, in order to modify a specific organism with the intent of changing one of its characteristics.

Food Standards Australia require foods with more than 1% GM to be identified as “genetically modified” on the label.

Genetically modified (GM) food refers to genetically engineered food plants. This practice is intended to improve the performance or production qualities of a plant, or to reduce loss of food/crops to natural pests such as insects.  Critics are concerned that genetic engineering poses a potential risk of biological disaster from unexpected side-effects, and gives bio-engineering companies too much power over our food supply and the natural world.

A genetically modified organism (GMO) in an organism whose genetic material has been altered by the process of genetic engineering.  Critics are concerned that GMOs may contribute to increased health risks to human and the environment.

Geology is the science of the Earth as a whole and the rocks from which it is formed.

Geothermal energy refers to the generation of energy by drilling and harvesting heat trapped deep within the earth.

Glass recycling refers to containers such as bottles and jars that can be recycled endlessly. When being recycled, glass is generally separated into the colour categories of brown, green and clear, for conversion into new containers, construction materials or fiberglass insulation.

Global warming refers to an increase in the Earth's surface temperature due to the accumulation of specific gases in the atmosphere. The terms ‘climate change’ and ‘global warming’ are often used to refer to global warming.

Green building refers to the practice of developing and implementing healthier and more resource-efficient practices for construction, renovation, operation, maintenance and demolition. Green building design incorporates environmentally sound principles of building and sustainable product use such as solar panels, skylights, and recycled building materials.

Green collar jobs refer to employment in emerging green industries such as renewable energy and carbon trading. It may also include jobs that reduce energy consumption, carbon emissions, water use, waste and pollution as well as protection of ecosystems and biodiversity.

The term green consumers, refers to people who purchase environmentally friendly products and services.

Green investment or ethical investment is a growing global and Australian trend in investment management.  Green investment refers to the practice of investing in companies that benefit the environment or support environmentally friendly products and services.

Green pesticides refer to pesticides that are derived from organic sources, which are considered to cause less harm to humans and animals, and their natural environment.

Green power refers to electricity generated from renewable resources sources such as wind, hydro and solar power.  The use of green power reduces the consumption of fossil fuels and their associated emissions. In Australia, ‘GreenPower’ is a government accreditation which ensures that energy retailers are investing in green power of behalf of customers that purchase this electricity source.

Green procurement refers to an organisation’s purchase of products and services that have a reduced impact on the environment, or consider issues relating to ethics, treatment of workers and safe working conditions.

A green roof is a standard roof that has been covered with soil and vegetation, typically grass.  Green roofs provide a range of benefits such as absorbing rainwater, providing insulation, creating a wildlife habitat and lowering urban air temperatures to combat the heat island effect. 

The greenhouse effect refers to the warming of Earth, which is caused by a buildup of certain gases (called greenhouse gases) that form a blanket in the Earth’s atmosphere. Small amounts of these gases are beneficial in keeping the Earth, but larger amounts produced by vehicles and heavy industry may hold too much heat and cause global warming.

Greenhouse gas (GHG) refers to any atmospheric gas that contributes to the greenhouse effect, which leads to climate change by warming global temperatures. The major greenhouse gases are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulphur hexafluoride (SF6).

Greenwashing is a term used to describe green marketing, advertising and other promotional activities that use misleading, vague, irrelevant or unsubstantiated environmental claims to sell a product or service. Greenwashing is a serious issue as it confuses consumers and creates a serious disadvantage for companies and industries that are trying to do the right thing.

Grey water refers to any domestic water that has been used in the home except for water from the kitchen and from toilets.  A greywater system allows for greywater to be collected and used on gardens for irrigation purposes. 

Grid connected solar power is a solar power system that is connected to the mains power supply. Any excess electricity that is generated by the system feeds into the mains supply. The owner of the solar power system may be able to earn 'credits' for feeding power to the grid.

Ground cover refers to vegetation grown to prevent soil erosion.

Groundwater is a supply of freshwater that is located underground.  Groundwater is derived from rainfall, snow, sleet and hail that soak into the ground and accumulates in lower layers of soil. Because groundwater is a major source of drinking water, there is growing concern over agricultural or industrial pollutants leaching pollutants into this water source.

Guerrilla gardening refers to the unauthorised planting of vegetation or crops on vacant public or private land.  The aim of guerrilla gardening is to improve neglected, empty or untidy spaces.  Guerrilla gardening often takes place at night to avoid unwanted attention, or it is done in plain sight to encourage community interaction.