2. The Greenhouse Effect

3. The Greenhouse Effect
• The term Greenhouse effect has been derived from a phenomenon
that occurs in a greenhouse.
• Greenhouse effect is a naturally occurring phenomenon that is
responsible for heating earth’s surface and atmosphere
• One-fourth of the incoming solar radiation is absorbed by the
atmospheric gases.
• One-fourth of it is reflected by the clouds and gases
• Only half of the incoming solar radiations falls on the earth and
heats it and a small portion is reflected back.
• Earth’s surface emits heat in the form of infrared radiations to the
space, but most of it is absorbed by gases like carbon dioxide,
nitrous oxide, chlorofluoro carbons and methane (greenhouse
gases).
• The molecules of these gases radiate heat energy that comes back
to earth’s surface and heats it up.
• The cycle is repeated till the long-wave radiations become
unavailable for absorption.

4. How Greenhouse
Effect works?

5. Greenhouse Gases
• A greenhouse gas is a gas in an atmosphere that absorbs and emits
radiation within the thermal infrared range.
• Atmospheric concentrations of greenhouse gases are determined by the
balance between sources (emissions of the gas from human activities and
natural systems) and sinks (the removal of the gas from the atmosphere by
conversion to a different chemical compound)
• In order, the most abundant greenhouse gases in Earth's atmosphere are:
– Water vapor (H2O)
– Carbon dioxide (CO2)
– Methane (CH4)
– Nitrous oxide (N2O)
– Ozone (O3)

6. Causes of Greenhouse Effect

7. Deforestation
• One of the man-made causes of the greenhouse
effect is deforestation. Deforestation increases
the amount of carbon dioxide in the atmosphere.
Also, due to the disappearance of trees,
photosynthesis cannot take place. Deforestation
is rampant today due to the burden of our needs
on land. The levels of deforestation have
increased by about 9% in recent times. Also, the
burning of wood causes it to decay, therefore
releasing more carbon-dioxide into the
atmosphere.

8. Burning of fossil fuels
• Greenhouse gases can also be released into the
atmosphere due to the burning of fossil fuels, oil,
coal and gas. These materials are used
increasingly and rampantly in industries. Most
factories also produce many gases which last for
a longer time in the atmosphere. These gases
contribute to the greenhouse effect and also
increase the global warming on the planet.
These gases are not naturally available in the
atmosphere. Therefore industries are also a
major cause of the greenhouse effect.

9. Electrical Appliances
• Other man-made causes of the increase in the
greenhouse effect is the emission of greenhouse gases
by electrical appliances. Even the humble refrigerator in
the house emits gases which contribute to the
greenhouse effect. These gases are known as
Chlorofluorocarbons (CFCs) and are used in
refrigerators, aerosol cans, some foaming agents in the
packaging industry, fire extinguisher chemicals, and
cleaners used in the electronic industry. Some
processes of the cement manufacturing industries also
act as a cause towards the greenhouse effect.

10. Population Growth
• Population growth is an indirect contributor
and one of the major causes of the
greenhouse effect. With the increase in
population, the needs and wants of people
increase. This increases the
manufacturing and the industry process.
This results in the increase of the release
of industrial gases which catalyze the
greenhouse effect.

11. Relative Contribution of various greenhouse gases to global warming

12. Facts on Greenhouse Effect!!
• Greenhouse effect is caused by greenhouse gases that trap the
reflected heat from getting out of the atmosphere.
• Some greenhouse effect is natural, and we need it for our survival.
• The problem is that the greenhouse effect has increased way too
much in the past 200 (particularly 40) years.
• It has increased in tact with increasing greenhouse gases.
• It is obvious that it is caused by humans because:
• the unnaturally quick increase started when the western
world started to be industrialized
• we know that an industrialized world causes an increase in
greenhouse gases - the main causes of the greenhouse
effect
• If the greenhouse effect did not exist, the Earth would be cooler by
about 33˚C on average

13. Global WarminG

14. What is Global Warming?
Global warming is a gradual increase in
the overall temperature of the earth's
atmosphere generally attributed to the
greenhouse effect caused by increased
levels of carbon dioxide, CFCs, and
other pollutants.

15. Graphs showing global average
temperature

16. What is the Difference between global
warming and climate change?
• GLOBAL WARMING • CLIMATE CHANGE is
is the increase of the a broader term that
Earth’s average refers to long-term
surface temperature changes in climate,
due to a build-up of including average
greenhouse gases in temperature and
the atmosphere precipitation.

17. Portage Glacier Alaska
1914 2004
Evidence Of Global
warming

18. Colorado River-Arizona
2002 2003

19. Causes of Global Warming
• Increase in the level of greenhouse gases is mainly responsible for
global warming
• Release of methane gas from arctic tundra and wetlands is one of
the natural cause of global warming.
• Another natural cause is that the earth goes through a cycle of
climate change
• Overuse of the fossil fuels (Coal, Petroleum, Natural Gas) releases
a large amount of CO2 in the atmosphere.
• Deforestation is also one of the major causes of global warming as
trees play a important role in curbing the CO2 level in the
environment.

20. How is Global Warming Measured?
Changes in the mean global temperature
can be measured by:
• Ground based weather records kept over
a long time to track trends.
• Sea water temperature records
• Satellite imagery
• Wildlife and plant life distribution
• Sea ice records

21. Effects of Global Warming
• An increase in global temperature will cause sea levels to rise and will change
the amount and pattern of precipitation, and a probable expansion
of subtropical deserts.
• Warming is expected to be strongest in the Arctic and would be associated with
continuing retreat of glaciers, permafrost and sea ice
• Other likely effects of the warming include more frequent occurrence of
extreme-weather events including heat waves, droughts and heavy
rainfall, species extinctions due to shifting temperature regimes, and changes
in crop yields
• Over the 21st century, climate change is likely to adversely affect hundreds of
millions of people through increased coastal flooding, reductions in water
supplies, increased malnutrition and increased health impacts
• Warming above 3 °C could result in crop yields falling in temperate regions,
leading to a reduction in global food production.
• In small islands and mega deltas, inundation as a result of sea level
rise is expected to threaten vital infrastructure and human settlements.
This could lead to issues of statelessness for population from
countries including the Maldives and Tuvalu.

22. The Future
Other effects could happen later this century, if warming continues.
• Sea levels are expected to rise between 7 and 23 inches (18 and 59 centimeters)
by the end of the century, and continued melting at the poles could add
between 4 and 8inches (10 to 20 centimeters).
• Hurricanes and other storms are likely to become stronger.
• Species that depend on one another may become out of sync. For example,
plants could bloom earlier than their pollinating insects become active.
• Floods and droughts will become more common. Rainfall in Ethiopia, where
droughts are already common, could decline by 10 percent over the next 50
years.
• Less fresh water will be available. If the Quelccaya ice cap in Peru continues to
melt at its current rate, it will be gone by 2100, leaving thousands of people
who rely on it for drinking water and electricity without a source of either.
• Some diseases will spread, such as malaria carried by mosquitoes.
• Ecosystems will change—some species will move farther north or become
more successful; others won’t be able to move and could become extinct.
Wildlife research scientist Martyn Obbard has found that since the mid-1980s,
with less ice on which to live and fish for food, polar bears have gotten
considerably skinnier. Polar bear biologist Ian Stirling has found a similar
pattern in Hudson Bay. He fears that if sea ice disappears, the polar bears will
as well.

23. • Reduce the use of fossil fuels therefore reduce emission of
greenhouse gases.
• Improve energy efficiency
• Reduce deforestation and plant more trees
• Reduce the use of nitrogen fertilizers
• Use Public Transport
• Use Renewable Energy Like Wind Power
• Burn methane
• Use smart cooler, Heater & Air conditioners
• Tune up and maintain vehicles properly
• Clean the air in your house
• Reduce electricity usage to the maximum
• Prefer recycling.