Now, let’s put glaciers on the back burner for a minute
and heat up the
discussion
with
some talk about global warming.
One degree, it doesn’t sound
like that much huh? The Earth’s
temperature, at the surface, has increased around 1ºF since the
end of the 19th
century, with the last 20 years seeing some of the most accelerated
rates of
warming. This one-degree is having quite the impact (U.S. PIRG website, 2004). There
is still some debate regarding exactly
why and how the Earth is heating up; however, it is commonly known that
human
activity is a big contributor (EPA website, 2004).
Check out the graph below to see how global temperatures are increasing.
Do they mean that there
are too many people out exercising and heating
up the Earth? Not exactly!
The industrial revolution brought with it
chemical changes in the Earth’s atmosphere (EPA
website, 2004).
Most of the chemicals released already naturally occurred; it is
the
high levels that are causing concern.
Carbon dioxide has increased almost 30 percent,
methane-containing gases
have more than doubled, and nitrous oxide concentrations have seen an
increase
of 15 percent (EPA website, 2004). So, what’s the big
deal? Naturally occurring greenhouse
gases do not necessarily have a negative effect, in fact, they are
necessary. They help trap some heat in and
warm the
Earth making it hospitable for life.
It’s the over abundance of these gases that causes problems. The following image depicts the Greenhouse
effect.
(Image
Courtesy of the EPA webiste, 2004.)
The increase
in greenhouse gases released into
the atmosphere only amplifies this effect and is heating things up. Amazingly, around 6.6 tons of greenhouses
gases are emitted per person every year in the United States (EPA website, 2004). WOW!
In addition to this increase in gases released, deforestation is
not
helping matters. It is decreasing the
ability of the forest to remove CO2 from the atmosphere and, when
burned,
vegetation releases CO2 (U.S. PIRG website, 2004). It does not
appear that this global problem is going to be lessening anytime soon.
How is global warming affecting
glaciers?
