Chemistry · Ch 15 — Environmental Chemistry
Greenhouse Effect and Global Warming
Greenhouse Effect and Global Warming
In 1987, Jean Baptiste Fourier, a French mathematician and scientist, coined the term "Greenhouse Effect" for the trapping of heat in the atmosphere by certain gases.
Earth's atmosphere lets most of the Sun's visible light pass through and reach earth's surface. As the surface is heated by this sunlight, it radiates part of the energy back toward space -- but as longer wavelengths, in the infrared (IR). Some of this outgoing heat is trapped by CH₄, CO₂, CFCs and water vapour present in the atmosphere: these gases absorb IR radiation and effectively block a large portion of earth's emitted radiation, partly re-emitting the absorbed radiation back down to earth's surface. The surface therefore gets heated up further by this phenomenon, called the greenhouse effect.
So the greenhouse effect may be defined as the heating up of earth's surface due to the trapping, by the CO₂ layer in the atmosphere, of infrared radiation reflected by earth's surface. The resulting heating up of earth through the greenhouse effect is called global warming. …
What this figure shows. A labelled schematic titled 'The Greenhouse Effect': the Sun (top left) sends sunlight toward the earth; one caption notes some sunlight that hits the earth is reflected back to space while some becomes heat; a second caption, pointing at the atmosphere just above earth's curved surface, states that CO₂ and other gases in the atmosphere trap this heat, keeping the earth warm -- shown as zig-zag arrows bouncing between the at …