Carbon dioxide – CO2 is a naturally occurring greenhouse gas in the atmosphere. However the amount of it increases when we burn fossil fuels, leading to global warming.

Carbon footprint – a measure of the your impact on the environment in terms of the amount of greenhouse gases produced, measured in units of carbon dioxide.

Carbon monoxide – a colorless, odorless and highly toxic gas commonly created during combustion.

Carbon neutral – a company, person or action either not producing any carbon emissions or if it does have been offset elsewhere.

Carbon offsetting – see offsetting.

Carbon rationing – limiting the amount of carbon you use each year. Carbon rationing action groups (crags) help you reduce your carbon footprint.

Carbon sink – carbon dioxide is naturally absorbed by things such as oceans, forests and peat bogs. These are called carbon sinks.

Cap and Trade - An environmental policy tool that delivers results with a mandatory cap on emissions while providing sources flexibility in how they comply. Successful cap and trade programs reward innovation, efficiency, and early action and provide strict environmental accountability without inhibiting economic growth.

Carbon tax – a charge on fossil fuels based on their carbon content.

CFL - Fluorescent light bulbs that fit into a standard light bulb socket and use a fraction of the energy of their incandescent counterparts.

Chlorofluorocarbons – CFCs are man-made chemical compounds containing carbon, chlorine, fluorine and sometimes hydrogen. Often used in older fridges and air conditions, the chlorine in CFCs damage the ozone layer.

Climate change – a change in temperature and weather patterns due to human activity like burning fossil fuels.

Composting – a process whereby organic wastes, including food and paper, decompose naturally, resulting in a produce rich in minerals and ideal for gardening and farming as a soil conditioner, mulch, resurfacing material, or landfill cover.

Conservation – preserving and renewing, when possible, human and natural resources.

Cradle-to-Cradle - A term used to describe a material or product that is recycled into a new or similar product at the end of its intended life.

Cradle-to-Grave - A term used to describe a material or product that is disposed (landfill, incineration, etc) of at the end of its intended life.