Halos are CFC (other greenhouse gases halocarbon) used, for instance, in firefighting equipment.
Greenhouse Effect is heating of the planet due to the increased density of the trace greenhouse gases in the atmosphere. They have the effect of increasing absorption of sunlight by preventing the outward radiation of heat from the Earth.
Waste to Energy (WTE) is the term used to describe the conversion of waste by-products into useful electricity (steam-generated).
Global Warming Potential (GWP) is an index, based upon radiate attributes of greenhouse gases, compared to that of carbon dioxide. The global warming potential appears as the combined effect of the various lengths of time that these gases remain in the atmosphere and their relative effectiveness in absorbing outgoing infrared radiation.