this slide contains the information about ozone layer depletion , its casue, effects and solution.

1. -MAMATA DHAKAL
Bsc nursing

2. OZONE LAYER DEPLETION

5. The Ozone Layer
• Sunscreen of earth
• Most atmospheric ozone is concentrated in a layer in the stratosphere,
about 9 to 18 miles (15 to 30 km) above the Earth's surface .
• Ozone is a molecule that contains three oxygen atoms. At any given
time, ozone molecules are constantly formed and destroyed in the
stratosphere.

6. • The ozone layer or ozone shield is a region of Earth's stratosphere that
absorbs most of the Sun's ultraviolet radiation.
• It contains a high concentration of ozone (O3) in relation to other parts of
the atmosphere, although still small in relation to other gases in the
stratosphere.
• Ozone (O3) is a gas which is present naturally within Earth’s atmosphere.
It is formed of three oxygen atoms (giving it the chemical formula, O3). Its
structure means that it’s much less stable than oxygen (O2), and is
therefore much more reactive; this means it can be more easily formed
and broken down through interaction with other compounds.

7. • The ozone layer in the stratosphere absorbs a portion of the
radiation from the sun, preventing it from reaching the planet's
surface. Most importantly, it absorbs the portion of UV light
called UVB.
• UVB has been linked to many harmful effects, including skin cancers,
cataracts, and harm to some crops and marine life.

8. What are ozone-depleting substances?
• Ozone-depleting substances (ODS) are halogen gases
containing chlorine and/or bromine which have the potential to
break down ozone in the stratosphere.
• There are a significant number of ODS, including
chlorofluorocarbons (CFCs), hydrochlorofluorocarbons
(HCFCs), methyl chloride and bromide, and halons.

9. Ozone depleting substances include:
• chlorofluorocarbons (CFCs)
• hydrochlorofluorocarbons (HCFCs)
• hydrobromoflurocarbons (HBFCs)
• halons
• methyl bromide
• carbon tetrachloride
• methyl chloroform.

10. They have been used as:
• refrigerants in commercial, home and vehicle air conditioners
and refrigerators
• components in electrical equipment
• industrial solvents
• solvents for cleaning (including dry cleaning)
• aerosol spray
• fumigants.

11. • When chlorine and bromine atoms come into contact with
ozone in the stratosphere, they destroy ozone molecules.
One chlorine atom can destroy over 100,000 ozone
molecules before it is removed from the stratosphere.
Ozone can be destroyed more quickly than it is naturally
created.

12. • Not all chlorine and bromine sources contribute to ozone layer
depletion. For example, researchers have found that chlorine from
swimming pools, industrial plants, sea salt, and volcanoes does not
reach the stratosphere. In contrast, ODS are very stable and do not
dissolve in rain.Thus, there are no natural processes that remove the
ODS from the lower atmosphere.

13. • One example of ozone depletion is the annual ozone "hole" over
Antarctica that has occurred during the Antarctic spring since the early
1980s. This is not really a hole through the ozone layer, but rather a
large area of the stratosphere with extremely low amounts of ozone.

14. Effects of ozone depletion for humans and
the environment
• Ozone layer depletion causes increased UV radiation levels at the
Earth's surface, which is damaging to human health.
• Negative effects include
- Increases in certain types of skin cancers,
-eye cataracts
- immune deficiency disorders
-UV radiation also affects terrestrial and aquatic ecosystems,
- altering growth,
- food chains and
-UV rays also affect plant growth, reducing agricultural
productivity

15. What can we do ?

16. Healing the planet starts in your garage,
in your kitchen, and at your dining-room
table.

17. Plant trees

18. What to do:
• Plant trees in tropical rainforests in Brazil, Indonesia, India,
Colombia, and Madagascar
• Protect what remains of our existing tropical forests through
nonprofits such as Cool Earth

19. • But not all forests are created equal – some remove carbon
from our atmosphere more effectively than others. According to
a paper published in Science Advances, tropical forests in
countries like Brazil, Indonesia, and India will most efficiently
pull carbon out of the atmosphere, since they’re home to a huge
amount of biodiversity and play a major role in the planet’s air
and water cycle.

20. Create more sustainable transportation
habits

21. What to do:
• Do at least one of these things:
• Instead of ordering a private ride, do a rideshare
• Avoid rapid acceleration and braking, and turn on cruise control
on longer trips
• Walk and bike to your destination whenever possible
• When buying a new car, choose a climate-friendly option

22. • Why it’s impactful:
• As aforementioned, cars are one of the biggest contributors to
climate change: 82% of emissions from transportation come
from cars. And while cutting automotive transportation out of
your life would make the most impact, this isn’t possible for
most people. So instead, tweak a few habits that will have a
bigger collective impact.

23. Lower your heating bill

24. What to do:
• In the winter, take steps to lower your heating bill:
• Set your thermostat at 68 degrees F, and lower your home’s
temperature 7-10 degrees for 8 hours a day. (But don’t turn
down the heat more than 10 degrees if it’s only for a few hours-
it’ll take too much energy to heat back up.)
• Shore up your windows, seal up the doors, and plug up dafty
holes

25. Why it’s impactful:
• Electricity is one of the biggest causes of greenhouse gas
emissions, and heating systems are the single biggest energy
expense in the home. So lowering your heating bills is the most
impactful way reduce your electricity consumption (and isn’t so
bad for your wallet, either).
• In addition to monitoring your thermostat, improving insulation
and airtightness through your walls, roof, and windows is a
great way to avoid heat from escaping your home, since the
biggest sources of heat loss are your walls (35%), roof (20%),
and windows (15%).

26. Divest from coal, and encourage others to
do the same

27. • What to do:
• Use alternative source

28. • Why it’s impactful:
• Coal-burning power plants are by far the biggest emitters of
carbon dioxide in our atmosphere, according to the Natural
Resources Defense Council.

29. Advocate for a healthy planet

30. What to do:
• Support climate legislation by doing one or more of these
things:
• Send a letter to party leaders and candidates telling them your
vote depends on their stance on global warming
• Volunteer for a candidate that supports efforts to stop global
warming
• Talk to friends and family about the importance of voting for
climate action
• Write a letter to your elected leaders to support and implement
a set of climate solutions

31. Why it’s impactful:
• Reminder: 100 companies produce 71% of emissions worldwide.
What will compel big companies to act sustainably consistently, on a
large scale? Lawmakers.
• They can:
• Place limits on the amount of carbon companies are allowed to emit
• Provide resources to prevent emissions leaks from equipment
• Subsidize efficient industrial technology to make it more affordable
• They can also help individuals act more sustainably. Copenhagen’s
government is working to make it the world’s first carbon-neutral city
by 2025, by installing bike lanes across the city, restricting polluting
cars, and building new wind turbines.
• And how can we enact political change? It all starts with you.

32. Invest in energy-efficient appliances.

33. • Energy efficiency is the lowest-cost way to reduce emissions,”.
• When shopping for refrigerators, washing machines, and other
appliances, look for the Energy Star label. It will tell you which
are the most efficient.

34. Reduce water waste.

35. • Saving water reduces carbon pollution, too. That's because it
takes a lot of energy to pump, heat, and treat your water. So
take shorter showers, turn off the tap while brushing your teeth,
and switch to WaterSense -labeled fixtures and appliances

36. Actually eat the food you buy

37. • Approximately 10 percent energy use goes into growing,
processing, packaging, and shipping food, about 40 percent of
which just winds up in the landfill.

38. Buy better bulbs.

39. • LED lightbulbs use up to 80 percent less energy than
conventional incandescents. They’re also cheaper in the long
run

40. Rethink planes, trains, and automobiles.

41. • Choosing to live in walkable smart-growth cities and towns with
quality public transportation leads to less driving, less money
spent on fuel, and less pollution in the air. Less frequent flying
can make a big difference, too. “Air transport is a major source
of climate pollution,” “If you can take a train instead, do that.”

42. Shrink your carbon profile

43. • You can offset the carbon you produce by purchasing carbon
offsets, which represent clean power that you can add to the
nation’s energy grid in place of power from fossil fuels.

44. Reduce, Reuse and Recycle

45. • Landfills are the major contributor of methane and
other greenhouse gases. When the waste is burnt, it releases
toxic gases in the atmosphere, which results in global warming.
Reusing and recycling old items can significantly reduce your
carbon footprint as it takes far less energy to recycle old
items than to produce items from scratch

47. Go Solar

48. • Many people have caught the energy-efficient bandwagon of
solar energy. Having solar panels installed is something readily
possible and available

49. Look for Renewable Fuel Options

50. • If you can’t afford an electric car, buy the cleanest gasoline as
possible. When car shopping, look at the benefits of options that
provide renewable fuel. Although it may be a pretty penny now,
you’re on the ground level of forwarding thinking.