GlossaryHeading	GlossaryDetails
Radiative forcing	Radiative Forcing (RF) is the measurement of the capacity of a gas or other forcing agents to affect that energy balance, thereby contributing to climate change. RF generally expresses the change in energy in the atmosphere due to GHG emissions.
Radon	A colourless, naturally occurring, radioactive, inert gaseous element formed by radioactive decay of radium atoms in soil or rocks. It is a major source of indoor air pollution
Relative humidity	Measure (as a percentage) of the amount of water vapour in a certain mass of air compared with the maximum amount it could hold at that temperature.
Remote Sensing	Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object. It is the scanning of the earth by satellite or high-flying aircraft in order to obtain information about it.
Ringelmann Chart	A series of charts, numbered 0 to 5, that simulate various smoke densities by presenting different percentages of black. A Ringelmann No. 1 is equivalent to 20 percent black; a Ringelmann No. 5 is 100 percent black. They are used for measuring the opacity or equivalent obscuration of smoke arising from stacks and other sources by matching the actual effluent with the various numbers, or densities, indicated by the charts.
Risk Assessment	An evaluation of risk which estimates the relationship between exposure to a harmful substance and the likelihood that harm will result from that exposure.
Risk Management	An evaluation of the need for and feasibility of reducing risk. It includes consideration of magnitude of risk, available control technologies and economic feasibility.