gas

includes natural gas (both associated and non-associated with petroleum deposits, but excluding natural gas liquids) and gas-works gas.

gas-to-liquids

a process featuring reaction of methane with oxygen or steam to produce syngas (a mixture of hydrogen and carbon monoxide) followed by synthesis of liquid products (such as diesel and naphtha) from the syngas using Fischer-Tropsch catalytic synthesis. The process is similar to those used in coal-to-liquids or biomass-to-liquids.

geothermal

energy available as heat emitted from within the earth’s crust, usually in the form of hot water or steam.

global warming

the observed increased of the global average temperature as a result of human and other activities, including through the increased concentration of greenhouse gases such as CO2 from energy.

green certificates

amount of electricity produced by green methods;set by regulations but can be traded.

greenhouse effect

greenhouse gases (such as water vapour, CO2, methane, etc) in the atmosphere absorb and re-emit heat being radiated from the earth, trapping warmth. 

greenhouse gases

referring to gases that contribute to the greenhouse effect by absorbing infrared radiation (heat). Anthropogenic emissions of six greenhouse gases are covered by the Kyoto Protocol.

gross domestic product (GDP)

a country’s annual economic output.