Green house effect and ozone depletion

1. GREEN HOUSE EFFECT AND
OZONE DEPLETION
Presented by
M.Shravan Kumar Reddy.
M.Sc. Agronomy 1st year
RAM /2016-03.

2. • When we discuss about the Green house
effect we need to know the following things .
• What is Green House Effect ?& process.
• What are the causes of green house effect ?
• What are the consequences of green house
effect?
• Can we control the green house effect?

3. GREEN HOUSE EFFECT
• The greenhouse effect is a natural process
that warms the Earth’s surface. When the
Sun’s energy reaches the Earth’s atmosphere,
some of it is reflected back to space and the
rest is absorbed and re-radiated by
greenhouse gases.
• The greenhouse effect is the process by which
radiation from a planet's atmosphere warms
the planet's surface to a temperature above
what it would be without its atmosphere

4. HOW GHE IS USEFUL???
• Without green house effect we can not
survive in the planet earth bacause ,,
• The absorbed energy warms the atmosphere
and the surface of the Earth. This process
maintains the Earth’s temperature at around
33 degrees Celsius warmer than it would
otherwise be, allowing life on Earth to exist.

5. • Without greenhouse gases, the average
temperature of Earth's surface would be about
−18 °C (0 °F), rather than the present average of
15 °C
• Green house gases
• Greenhouse gases include carbon dioxide,
methane, nitrous oxide, ozone and some
artificial chemicals such as chlorofluorocarbons
(CFCs).
.

7. Greenhouse effect
• Step 1: Solar radiation reaches the Earth's atmosphere -
some of this is reflected back into space.
• Step 2: The rest of the sun's energy is absorbed by the
land and the oceans, heating the Earth.
• Step 3: Heat radiates from Earth towards space.
• Step 4: Some of this heat is trapped by greenhouse
gases in the atmosphere, keeping the Earth warm
enough to sustain life.
• Step 5: Human activities such as burning fossil fuels,
agriculture and land clearing are increasing the amount
of greenhouse gases released into the atmosphere.
• Step 6: This is trapping extra heat, and causing the
Earth's temperature to rise.

8. Causes of green house effect
Green House gases : Includes CO2 ,CH4,O3, NO ,NO2
and CFC etc…. Though green house gases are helpful to
maintain atmosphere temparature but increased
amounts over optimum is not at al usefull…
 Contribution of clouds to Earth's greenhouse effect
The major non-gas contributor to Earth's greenhouse
effect, clouds, also absorb and emit infrared radiation
and thus have an effect on radiative properties of the
greenhouse gases.

9. Compound Formula
Concentration in
atmosphere[ (ppm
)
Contribution
(%)
Water vapor and
clouds
H2O 10–50,000 36–72%
Carbon dioxide CO2 ~400 9–26%
Methane CH4 ~1.8 4–9%
Ozone O3 2–8 3–7%

12. • Anthropogenic factors:
• This includes the man made processes like Burning
of fossil fuels and deforestation , paddy cultivation ,
use of GH gases like CFC and halons in refrigiration
and fire suppression systems , and indiscriminate
use of fertilizers mostly N fertilizers ,etc…leads to
increased GHE.

15. Enhanced green house effect
• The problem we now face is that human activities
– particularly burning fossil fuels (coal, oil and
natural gas), agriculture and land clearing – are
increasing the concentrations of greenhouse
gases. This is the enhanced greenhouse effect,
which is contributing to warming of the Earth.
• Enhanced green house effect lead to
GLOBAL WARMING.

16. Consequences of greenhouse-effect
• The effects due to GHE include:
• More drought and more flooding
• Less ice and snow
• More extreme weather incidents
• Rising sea level.

17. More drought and more flooding
• When the weather gets warmer, evaporation from both
land and sea increases. This can cause drought in areas of
the world where the increased evaporation is not
compensated for by more precipitation.
• In some regions of the world this will result in crop failure
and famine especially in areas where temperatures are
already high. The extra water vapour in the atmosphere
will fall again as extra rain, which can cause flooding in
other places in the world.

18. Less ice and snow
• Worldwide, glaciers are shrinking rapidly at
present. Ice appears to be melting faster than
previously estimated. In areas that are dependent
on melt water from mountain areas, this can
cause drought and lead to lack of water supply.
• According to the IPCC, up to a sixth of the world's
population lives in areas that will be affected by
melt water reduction.

19. snow melting due to GHG

20. More extreme weather incidents
• The warmer climate will probably cause
more heatwaves, more violent rainfall and
also an increase in the number and/or
severity of storms.

22. Rising sea level
• Sea level rises because of melting ice and snow and
because of the thermal expansion of the sea (water
expands when warmed). Areas that are just above sea
level now, may become submerged.
• In countries with large areas of coastal lowland there will
be a dual risk of river floods and coastal flooding, which
will reduce the area for living and working.
• The increase in standing water may allow more insects
like mosquitoes and diseases spread by insects, such as
Lyme’s disease.

23. What evidence is there that the Earth’s
climate is changing?
According to IPCC
• Widespread decreases in glaciers and ice
caps have contributed to sea level rise.
• Increased sea levels :. Since 1961 the average
rate has been 1.8 mm per year but since 1993 this
has increased to 3.1 mm per year
• Increasing the temparatures over the years
passes
• It has been estimated that now at present around 2
degrees more temparature due to GHE.

25. • Increased amount of water vapour in the
atmosphere :
• This is because of the fact that warmer air can hold
more water than colder air. This is in turn increase in
air temparature is due to GHE.

28. CAN WE CONTROL GREEN
HOUSE EFFECT

30. Ways to Reduce Greenhouse Gases
• Reduce, Reuse, Recycle
Buying products with minimal packaging will help
to reduce waste. By recycling half of your
household waste, you can save 2,400 pounds of
carbon dioxide annually.
• Use Less Heat and Air Conditioning
Adding insulation to your walls and installing
weather stripping or caulking around doors and
windows can lower your heating costs more than
25 percent, by reducing the amount of energy
you need to heat and cool your home.

31. • Replace Your Light Bulbs
Wherever practical, replace regular light bulbs with
compact florescent light (CFL) bulbs.
• Drive Less and Drive Smart
Less driving means fewer emissions. Besides saving
gasoline, walking and biking are great forms of exercise.
.
• Buy Energy-Efficient Products
Home appliances now come in a range of energy-
efficient models, and compact florescent bulbs are
designed to provide more natural-looking light while
using far less energy than standard light bulbs.

32. • Use Less Hot Water
Set your water heater at 120 degrees to save energy, and wrap
it in an insulating blanket if it is more than 15 years old. Buy
low-flow showerheads to save hot water and about 350 pounds
of carbon dioxide yearly.
• Use the "Off" Switch
Save electricity and reduce global warming by turning off lights
when you leave a room, And remember to turn off your
television, stereo and computer when you're not using them.
turn off the water when you’re not using it. While brushing
your teeth, shampooing the dog or washing your car, turn off
the water until you actually need it for rinsing.
• Plant a Tree
Trees absorb carbon dioxide and give off oxygen. A single tree
will absorb approximately one ton of carbon dioxide during its
life

33. • Encourage Others to Conserve
• This is last but not least ….this is most important .because we can
control the green house effect all in the society put their efforts ..its
not possible to control by an individual
• So share information about recycling and energy conservation with
your friends, neighbors and co-workers, and take opportunities to
encourage public officials to establish programs and policies that are
good for the environment.

34. OZONE DEPLETION

36. What is Ozone Depletion?
• ozone layer depletion, is simply the wearing
out (reduction) of the amount of ozone in the
stratosphere

39. Why Ozone Layer is Necessary?
• It is necessary because An essential property of ozone
molecule is its ability to block solar radiations of wavelengths
less than 290 nanometers from reaching Earth’s surface. In
this process, it also absorbs ultraviolet radiations that are
dangerous for most living beings. UV radiation could injure
or kill life on Earth.
• For humans, excessive exposure to ultraviolet radiation leads
to higher risks of cancer (especially skin cancer) and cataracts.
It is calculated that every 1 percent decrease in ozone layer
results in a 2-5 percent increase in the occurrence of skin
cancer. Other ill-effects of the reduction of protective ozone
layer include – increase in the incidence of cataracts,
sunburns and suppression of the immune system.

41. The Impacts of Ozone Depletion
• Harm to human health:
• More skin cancers, sunburns and premature aging of
the skin.
• More cataracts, blindness and other eye diseases: UV
radiation can damage several parts of the eye,
including the lens, cornea, retina and conjunctiva.
• Weakening of the human immune system
(immunosuppression). Early findings suggest that too
much UV radiation can suppress the human immune
system, which may play a role in the development of
skin cancer.

44. • Adverse impacts on agriculture, forestry and natural
ecosystems:
• Most of the crops are senisitive to increased UV, resulting
in reduced growth, photosynthesis and flowering. These
species include wheat, rice, barley, oats, corn, soybeans,
peas, tomatoes, cucumbers, cauliflower, broccoli and
carrots.
• Only a few commercially important trees have been
tested for UV (UV-B) sensitivity, but early results suggest
that plant growth, especially in seedlings, is harmed by
more intense UV radiation.

45. • Damage to marine life:
• In particular, plankton (tiny organisms in
the surface layer of oceans) are threatened
by increased UV radiation. Plankton are the
first vital step in aquatic food chains.
• Loss of biodiversity in our oceans, rivers
and lakes could reduce fish yields for
commercial and sport fisheries.

46. • Animals:
• In domestic animals, UV overexposure may cause
eye and skin cancers.
• Materials:
• Wood, plastic, rubber, fabrics and many construction
materials are degraded by UV radiation.
• The economic impact of replacing and/or protecting
materials could be significant.

47. Causes of depletion of ozone layer
• Natural causes of depletion of ozone layer: Ozone layer has
been found to be affected by certain natural
phenomena such as Sun-spots and stratospheric winds.
This is not more than 1-2%
• Man-made causes of depletion of ozone layer: The
main cause for the depletion is excessive release of
chlorine and bromine from man-made compounds such
as chlorofluorocarbons (CFCs), halons, CH3CCl3 (Methyl
chloroform), CCl4 (Carbon tetrachloride), HCFCs ,HBFCs
and methyl bromide are found to have direct impact on
the depletion of the ozone layer. These are categorized
as ozone-depleting substances (ODS).

49. Main Ozone Depleting Substances (OCD)
• Chlorofluorocarbons: Account for more than
80% of ozone depletion. Used in freezers, air
cooling component, dry-cleaning agents,
hospital sterilants.
• Methyl Chloroform: Used for vapour
degreasing, some aerosols, cold cleaning,
adhesives and chemical processing.
• Hydrochlorofluorocarbons: Substitutes for
CFC’s but still play a vital role in ozone
depletion.
• Carbon Tetrachloride: Mainly used in fire
extinguisher

50. • Chlorofluorocarbons are released into the atmosphere
due to:
• Cleaning Agents
• Coolants in refrigerators
• Packing material
• Air conditioning
• Aerosol spray cans etc

53. • Measures to Protect Ozone Layer
Depletion:
 The use of plastic should be banned in the country.
 The production and use of CFCs should be banned.
 The use of CFCs in aerosol, spray cans, egg crates etc.
should be banned and their substitutes should be
used.
 New technologies should be adopted to recapture
the CFCs released from the air-conditioners and
refrigerators.
 Limit private vehicle driving

54. • Use eco-friendly household cleaning products
• Reduce the use of pesticides
• Developing stringent regulations for rocket
launches
• Banning the use of dangerous nitrous oxide.