Earth getting warmer?
Normally the local and
regional temperatures fluctuate naturally. But over
past 100 years average global temperature has
risen at an alarmingly rate in the history. Scientists
believe that this trend is dangerous. Experts say that
unless we do something about reducing the greenhouse
emissions, average temperatures of earth could be 3 to 9
degrees higher by the turn of century.
Global Warming Bad?
The earth is
naturally warmed by rays (or radiation)
from the sun which pass through the
earth's atmosphere and are reflected
back out to space again.
The atmosphere's made up of layers of
gases, some of which are called
'greenhouse gases'. They're mostly
natural and make up a kind of thermal
blanket over the earth.
This lets some of the rays back out of
the atmosphere, keeping the earth at the
right temperature for animals, plants
and humans to survive (60°F/16°C). But
Pumping much more Co2 than it naturally
occurs can cause temperatures to rise
much more and much faster, which then
can lead to disastrous repercussions.
is Causing Global Warming?
concluded that human activities are contributing to
global warming by adding large amounts of heat-trapping
gases to the atmosphere. Our fossil fuel use is the main
source of these gases. Every time we drive a car, use
electricity from coal-fired power plants, or heat our
homes with oil or natural gas, we release carbon dioxide
and other heat-trapping gases into the air. The second
most important source of greenhouse gases is
deforestation, mainly in the tropics, and other land-use
Since pre-industrial times, the atmospheric
concentration of carbon dioxide has increased by 31
percent. Over the same period, atmospheric methane has
risen by 151 percent, mostly from agricultural
activities like growing rice and raising cattle.
it happens ?
The atmosphere surrounding the earth is
mainly composed of Nitrogen (about
seventy eight percent, and Oxygen
(twenty one percent) with water vapor
and various trace gases making up the
rest. There are quite a few trace gases,
such as; Argon, Carbon Dioxide, Neon,
Helium, Methane, Hydrogen, Nitrous Oxide
and Ozone. These gases, are often called
green house gases. Because during the
day the earth soaks up heat, and these
gases act like a greenhouse trapping in
the heat. Some of the heat is radiated
back out into space, and if weren’t for
these gases things would freeze over
during the night. The issue of course is
the increase in greenhouse gases, which
is trapping in more heat, and causing a
rise in global temperature.