VOLCANOES SAVE US FROM GLOBAL WARMING?
by Whit Gibbons
February 17, 2008
about global climate change are as polarized as those about whether people
should talk on cell phones while driving, be allowed to smoke in privately
owned restaurants, or let their pet cats outdoors.
base temperature has fluctuated over eons or even centuries. That is a
verified fact. The dispute arises over whether temperatures are significantly
warmer now than they were a couple of centuries agowarm enough to
cause noticeable environmental changes. I find the evidence for climate
change convincing. Some talk radio hosts and even some scientists do not.
The next arguable point, and there is argument aplenty, is whether the
fundamental cause of climate change is carbon emissions from the industrialized
countries and whether, if that is true, we should do anything about it.
at the international level abound. Should countries place controls on
fossil fuel use? Should we make a global effort to ameliorate what some
view as a serious environmental problem? If so, how should we set about
this task? Because of the strong political and personal opinions surrounding
this issue, including many self-serving ones on both sides, a satisfactory
resolution does not seem to be on the near horizon.
as I do that global warming is a reality, I think we will find out what
the consequences of melting polar ice caps and shorter winters really
are. But that outcome might be delayed by a natural event: a volcanic
eruption of a magnitude that actually affects the world's climate.
influences on global warming could be masked temporarily by the eruption
of a major volcano. Global cooling from a volcano can occur as a result
of sun-shielding by airborne products from the eruptions. The ash, most
of which settles to earth within a few weeks, is not the volcanic product
that blocks the sun's rays for a long period. Sun-shielding is caused
by tiny droplets of sulfuric acid that can remain in the stratosphere
for up to three years.
activity at the earth's surface has been around since the crust cooled,
and it will continue for several billion years. Many people remember the
eruption of Mount Saint Helens in 1980, the most destructive volcanic
eruption to date in the United States. Other volcanoes have also made
lasting impressions, such as Vesuvius, which resulted in lots of mummified
bodies in the town of Pompeii. Unzen in Japan and Mount Pinatubo in the
Philippines became revitalized in the early 1990s and garnered worldwide
is calculated to have spewed out more than 20 million tons of sulfur dioxide
that reached the stratosphere. Global cooling effects from major volcanic
eruptions of that magnitude have the potential to confound interpretations
of already controversial studies to determine if global warming from human
activities is a phenomenon to be apprehensive about.
(sometimes called Krakatoa) erupted in 1833 it had a major influence on
the environment. If something of that magnitude occurred today, most news
stories about human-caused atmospheric change would seem trivial. Because
the earth's temperature would change dramatically, the finger-pointing
about global warming would become completely irresolvable.
blew its lid, an eighteen-square-mile volcanic island located between
Australia and Borneo disappeared. The sound of the Krakatau eruption was
reportedly heard more than 3,000 miles away. Tidal waves were created
in southeast Asia, and at least 36,000 people perished in coastal cities.
Rocks and ash were reportedly thrown more than 15 miles high. The ash
cloud was so thick that villages 150 miles away were in total darkness
as famous as Krakatau's performance, Tamburo's eruption produced even
more dramatic environmental results. In 1815 that Indonesian volcano spewed
enough ash and aerosols into the atmosphere to create a cold snap. In
Europe, 1815 became known as "the year without summer."
eruption the magnitude of Krakatau's or Tamburo's would lay all arguments
about global climate change to rest for awhile. And we can certainly expect
more environmental drama from volcanoes in the future, although no one
knows when and where. The results of such an eruption would be spectacular
and far reaching. I kind of look forward to it.
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