1. Greenhouse is Good
In the absence of an atmosphere, Earth’s surface temperature would
be about –18°C, or 0°F, which is way too cold for life.
Earth is habitable because of the ‘greenhouse effect’ -a slightly
inaccurate term for the heating of Earth’s atmosphere due to the
presence of greenhouse gases such as water vapor, carbon dioxide
(CO2), methanes (CH4)
and nitrous oxide (N2)). Greenhouse gases
have just the right molecular structure to absorb infrared radiation
that the Earth emits. It re-emits most of that infrared energy in
all directions, warming the atmosphere to its comfortable average
temperature of 15°C (60°F). So the greenhouse effect is
a good thing.
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(In a real greenhouse, it’s warmer inside because the
structure prevents cooler outside air from mixing with the
warmer air inside the greenhouse.)
But an enhanced greenhouse effect can lead to global warming.
image courtesy EPA |
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