Definition of the Global warming is
the rise in the average temperature of the Earth's near-surface air and
oceans. OR It observed and projected increases in the average
temperature of Earth's atmosphere and oceans. OR Global warming refers
to an average increase in the Earth's temperature, which in turn causes
changes in climate.
A warmer Earth may lead to changes in
rainfall patterns, a rise in sea level, and a wide range of impacts on
plants, wildlife, and humans. When scientists talk about the issue of
climate change, their concern is about global warming caused by human
activities.
Earth was formed about 4.5 billion years ago and its
temperature has changed through history.it has been warmer in the
past,and sometimes much colder. But it is the speed at which earth is
heating up that is alarming. For the first btime in history, humans,not
nature are the main cause of earth’s changing climate or as it is
commonly known as Global warming.
Ice Ages –
for long periods of times- called ice ages-earth’s surface was almost
completely covered with ice. Much of the ice was stored in
glaciers.
Fossile fuels - All living things use
and store carbon. Millions years ago ,when plants and animals died,some
were buried, crushed, and fossilized under ground.oil,coal,natural gas
formed from this fossilized remains-this is why this is called fossile
fuels.
When we burn the fossile fuels we are releasing the large
amounts of carbon into the atmosphere as part of the gas carbon
dioxide. It is released naturally such as volcanoes, but humans and
machines we use are produce more carbon dioxide than ever before.70% of
the world’s energy is generated by burning the fossile
fuels.
What causes Global warming? Is it part of a
natural cycle?
Global warming is due to the build up of
greenhouse gases in the atmosphere, which form one sort of blanket over
the Earth,which traps the heat which is normally escape the atmosphere.
The main greenhouse gas is carbon dioxide, this is emitted from the
burning of fossil fuels.When we burn the fuel,gases are released, or
emitted, into the atmosphere. Our gas emission have been on the rise
since last century. When people started burning coal in factories to
produce power. As emissions have increased, sohas earth’s
temperature
What is Greenhouse gases –
Greenhouse gases are those which absorb the heat from the sun and help
warm the planet, which makes it possible for the the plants and animals
to live. Most greenhouse gases are the natural part of the life. For
example, human breaths out small amount of the carbon dioxide into the
air. But some human activities have caused some gases to buld up too
much. Many scientist belives this increase in greenhouse gases causing
global warming.
Which are Greenhouse gases?-
Carbon dioxide makes up more than 99percent of the greenhouse gases in
earth’s atmosphere.The remaining 0.6 percent contains methane,nitrous
oxide,ozone and halocarbons.
The Greenhouse
effects –The Greenhouse effect is a natural process discovered
in 18th century.it has kept our planet warm enough to support life for
billions of years.but as the amount of greenhouse gases increases, more
heat is trapped in the atmosphere. The natural process has sped up and
earth is getting hotter.
Greenhouse effect is the result of
absorption of heat by some greenhouse gases in the atmosphere and re-
radiate downward some of that heat. Most common example of the
greenhouse gas is the water vapour which is abundantly available in the
atmosphere, carbon dioxide and other trace gases. Without this natural
greenhouse effect.
The temperature of the Earth would be about -18°C
instead of 14°C.The greenhouse effect is the process in which the
emission of infrared radiation by the atmosphere warms a planet's
surface. Solar energy,only about half of the sun’s energy makes it to
earth’s surface. The rest is bounced back or trapped by clouds and the
atmosphere itself.
