Global Warming in a Nutshell
Greenhouse gases like carbon dioxide are transparent to in-coming shortwave solar radiation. This radiation reaches
the earth's surface, heats it, and re-radiates it as long-wave radiation. Greenhouse gases are opaque to long-wave
radiation and therefore, heat is trapped in the atmosphere. As greenhouse gases buildup, this opacity is increased
and more heat is trapped in the atmosphere.
Interestingly, the temperature of the stratosphere (the upper part of the atmosphere that extends 10-50 km above
the surface of the earth) actually cools during warming events. Some global warming opponents have meretriciously
cited this phenomenon as evidence of current global cooling.
Global warming is believed to have a time lag of around 50 years due to the thermal inertia of oceans. Thus the
effects from the emissions of the postwar period are not yet apparent today.
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