BIOLOGY FORM 4 CHAPTER 9

1
GLOBAL WARMING
2

• Green house effect is an important natural
  process.
• Without it, the Earth would be too cool for the
  survival of living organisms.
• Carbon dioxide is the main green house gas.
• Buthuman activities had released more green
  house gases to the atmosphere. CFC, methane,
  nitrous oxide and ozone.
• The green house effect. Will increase the Earth
  temperature
• This phenomenon known as GLOBAL WARMING.

3

• Other things we do send greenhouse gases into the
  air too
• The trash that we send to landfills produces a
  greenhouse gas called methane.
• Whenever we drive or ride in a car, we are
  adding greenhouse gases to the
• atmosphere.
• When factories produce things that we buy and
  use everyday, they too are
• sending greenhouse gases into the air.

4
Earth has been warmed by about 1ºF (0.6 C) over
the past 100 years. And way this happened?
Global Warming Global warming refers to an
average increase in the Earth's temperature,
which in turn causes changes in climate. The
Greenhouse Effect Greenhouse gases make the
Earth warmer by trapping energy in the
atmosphere. Have you ever seen a greenhouse?

5

• The sun heats up the Earth. Some
• of the suns solar rays bounce off
• of the Earths atmosphere and
• return to outer space. Some make
• it all the way to the surface of the
• Earth.
• 2. The rays that reaches the Earth warm
• the Earth. When the Earth is warm,
• it radiates its own rays of heat, called
• infrared rays. Some of these rays
• escape to outer space.
• 3. Others are absorb by gases called
• greenhouse gases which radiate
• heat. Greenhouse gases allow the
• earth to be in just the right temperature
• for life.

6

• Sometimes little things can turn into big things.
• Human Health
• Climate changes may affect people's health both
  directly and indirectly.
• Ecological Systems
• Alter the world's habitats and ecosystems all
  living things.
• Sea Level Rise
• Global warming may make the sea level become
  higher. Crops and Food Supply
• cold places - chance to grow crops in new areas.
  
• warm places - bring drought.

7
When the Earth temperature is increase, It will
cause the melting of the ice sea. This
phenomenon, will increase the sea level. Can
you imagine what will happen if the ice still
melt year by year??
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The Majuro Atoll If sea level rises 20 inches then 80 of the Majuro Atol will be under water. Many other islands may also be submerged if sea level rises. (Photo courtesy of the National Oceanic and Atmospheric Administration/Department of Commerce)
Coral Bleaching The algae in this coral died giving it a bleached appearance. (Photo courtesy of the National Oceanic and Atmospheric Administration/Department of Commerce)
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Disappearing Ice Packs Warmer temperatures could affect the wildlife the artic regions because of the melting of the sea ice. Native peoples in these areas depend on the ice berg to hunt seals and walruses.
Increased Air Pollution Air pollution in high-density cities can be a health hazard to individuals with asthma. Photochemical pollutants tend to increase with warmer temperatures.
10

• Global warming may be a big problem, but there
  are many little things we
• can do to make a difference.
• 1.Governments can adopt a range of options for
  reducing greenhouse gas emissions, including
• encouraging the use of renewable energy sources
  (such as wind and solar power)
• eliminating subsidies that encourage the use of
  coal and oil by making them
• artificially cheap
• protecting and restoring forests, which serve as
  important storehouses of carbon
• 2.Individuals can reduce the need for fossil
  fuels and often save money by
• driving less and driving more fuel-efficient and
  less-polluting cars
• using energy-efficient appliances
• using less electricity in general