clipped from: mysite.verizon.net Just how much of the "Greenhouse Effect" is caused by human activity?
Water vapor constitutes
Earth's most significant greenhouse
gas, accounting for about 95% of
Earth's greenhouse effect (4). Interestingly, many "facts and figures' regarding
global warming completely ignore the powerful effects of water vapor in
the greenhouse system, carelessly (perhaps, deliberately) overstating human
impacts as much as 20-fold.
Human activites contribute slightly to greenhouse
gas concentrations through farming, manufacturing, power generation,
and transportation. However, these emissions are so dwarfed in comparison
to emissions from natural sources we can do nothing about, that even the
most costly efforts to limit human emissions would have a very small--
perhaps undetectable-- effect on global climate.
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A closer look at the numbers |