Energy obtained from the intensely hot molten magma deep in the earth, usually utilised by means of electricity generation by steam from underground sources.

Uncomfortable or disabling visual sensation caused by excessive and uncontrolled brightness.

The generic term for windows and the glass installed in them (see double glazing).

The theory - now generally accepted - that the average temperature of the earth is likely to rise due to a change in the heat balance of the earth and its atmosphere provided by the ‘greenhouse effect’ 1), as a result of human energy consumption and pollution, with unpredictable (so far) effects on the climatic and ecological balance of the earth.

Temperature measured by a thermometer with the bulb surrounded by a black globe of diameter  15.2cm (6 inch); the temperature thus measured combines air and radiant temperatures.

1)  the fact that glass and other transparent / translucent buildingmaterials, and the earth’s atmosphere, are relatively transparent to the high frequency radiation of the sun’s rays, while being relatively opaque to the low frequency radiation (heat) given off by building materials, contents and inhabitants, etc. and the earth’s surface in general; 

2)  the global warming effect that climate researchers warn of in relation to the pollution of the earth’s atmosphere by CO₂ and NOx gases etc., and thus its increased opacity to low frequency radiation.