2. Earth’s Atmosphere
The Earth's atmosphere is more
than just the air we breathe. It's
also a buffer that keeps us from
being peppered by meteorites, a
screen against deadly radiation,
and the reason radio waves can
be bounced for long distances
around the planet.
3. Earth’s Atmosphere
Troposphere
The lowest is the troposphere, which is the
layer that provides most of our weather. It
contains about four-fifths of the Earth's air,
but extends only to a height of about 11
miles (17 kilometers) at the Equator and
somewhat less at the Poles.
4. Earth’s Atmosphere
Stratosphere
Above the troposphere is the stratosphere.
It extends to a height of about 30 miles (50
kilometers) and includes the ozone layer,
which blocks much of the sun's harmful
ultraviolet rays. It is warmer than the
troposphere because of the energy from
the ultraviolet light absorbed by the ozone.
5. Earth’s Atmosphere
Stratosphere
Greenhouse Effect, the capacity of certain
gases in the atmosphere to trap heat
emitted from Earth’s surface, thereby
insulating and warming the planet. Without
the thermal blanketing of the natural
greenhouse effect, Earth’s climate would be
about 33°C (about 59°F) cooler—too cold
for most living organisms to survive.
6. Earth’s Atmosphere
Mesosphere
In this layer, the air temperature drops
again, down to nearly -180 degrees
Fahrenheit (-120 degrees Celsius) at the
top. Meteors generally burn up in the
mesosphere, which extends to a height of
about 52 miles (85 kilometers). This is why
the Earth's surface isn't pocked with meteor
craters, like the moon's.
7. Earth’s Atmosphere
Ionosphere
It extends to about 430 miles (690
kilometers) and is so thin it's generally
considered part of outer space. The
International Space Station and many
satellites orbit within the ionosphere.
It is named for the ions created within this
layer by energetic particles from sunlight
and outer space. These ions create an
electrical layer that reflects radio waves,
allowing radio messages to be sent across
oceans in the days before communication
satellites.
8. Earth’s Atmosphere
Exosphere
This tenuous portion of the Earth's
atmosphere extends outward until it
interacts with the solar wind. Solar storms
compress the exosphere. When the sun is
tranquil, this layer extends further outward.
Its top ranges from 620 miles (1,000
kilometers) to 6,214 miles (10,000
kilometers) above the surface, where it
merges with interplanetary space.
9. Weather
Weather is the state of the
atmosphere at a specific time and
place, with respect to temperature,
precipitation, and other factors
such as cloudiness.
10. Weather
Weather is generated by
many forces, some
obvious, some not. Warm,
humid air masses blowing
in from oceans, for
example, fuel rains.
Sunlight heats the land,
generating thermals that
help produce summer
thunderstorms.
11. Weather
Mountains and cities also
affect the weather. In
mountains this occurs
because the wind must
rise as it crosses over the
ridge. This lifts the air,
causing it to cool. That
produces clouds, rain, or
snow.
12. Weather
Cities, on the other hand,
produce urban "heat
islands" where roads,
parking lots, and rooftops
warm in the sun. This not
only raises the city's
temperature, but it can
affect the weather,
producing thunderstorms
in some cities or altering
storm tracks in others.
13. Climate
Climate isn't the same
thing as weather.
Weather is the condition
of the atmosphere over a
short period of time;
climate is the average
course of weather
conditions for a particular
location over a period of
many years.
14. Climate
One of the factors that influences climate is
the angle of the sun's rays. In the tropics, between
23.5° N and 23.5° S, there is at least one time of
year when the noontime sun is directly overhead and
its rays hit at a direct angle. This produces a hot
climate with relatively small temperature differences
between summer and winter.
17. Global Climate Change
Global Warming or
Climate Change is a
measurable increase
in the average
temperature of
Earth’s atmosphere,
oceans, and
landmasses.
18. Global Climate Change
Scientists believe that the Earth is
currently facing a period of rapid warming
brought on by rising levels of heat-trapping
gases, known as greenhouse
gases, in the atmosphere.
19. Global Climate Change
Since the beginning of the Industrial
Revolution in the mid-1700s, however,
human activities have added more and
more of these gases into the atmosphere.
21. Response to Climate Change
The first time climate change was recognized as a
serious problem by an international gathering was in
1979. The First World Climate Conference, held in
February of that year, was a major scientific meeting.
It issued a declaration calling on the world's
governments "to foresee and prevent potential man-made
changes in climate that might be adverse to
the well-being of humanity."
22. Response to Climate Change
A large number of international conferences on
climate change have been convened since
then. Attended by policy-makers, government
leaders, and scientists, they have addressed
both scientific and policy issues.
23. Response to Climate Change
In 1985 the Vienna Convention for the
Protection of the Ozone Layer was adopted. In
1987 a protocol under the Vienna Convention,
known as the Montréal Protocol, was signed
and later ratified by 36 nations, including the
United States.
24. Response to Climate Change
The Second World Climate Conference, held in
1990 in Geneva, was a particularly crucial step
towards a binding global convention on climate
change. Some of these meetings have taken place
under the auspices of the United Nations and its
specialized agencies. Others have been held within
regional for a such as the European Community, the
Commonwealth, and the South Pacific Forum.
25. Response to Climate Change
The December 1997 summit on global warming in
Kyōto, Japan, which included representatives from
the United States, the European Union (EU), and
many developing nations, reached an agreement
for reducing emissions of gases that many
scientists believe may lead to global warming and
depletes ozone layer.
27. Ozone Layer Depletion
The term "Ozone Layer" is used to
describe the ozone molecules present
in the stratosphere. The ozone layer
stretches around the entire globe of the
Earth like a bubble, filtering out harmful
ultraviolet radiation from the sun.
Destruction of the ozone layer
increases the amount of ultraviolet
radiation reaching the earth which can
cause severe effects on human health
and the environment.
29. Ozone Layer Depletion
What is Ozone Layer Depletion?
Ozone layer depletion is destruction of the upper
atmospheric layer of ozone gas, caused by
substances formed from breakdown of ozone
depleting substances. The main cause of this is
the release of chlorofluorocarbon (CFC).
30. Ozone Layer Depletion
Chlorofluorocarbons or CFC’s
are created and used in
refrigerators and air
conditioners. These are not
harmful to humans and have
been a benefit to us. Once
released into the atmosphere,
CFC’s are bombarded and
destroyed by ultraviolet rays. In
the process chlorine is
released to destroy the ozone
molecules.
33. Ozone Layer Depletion
NASA (2006) says ozone layer hole
5th biggest on record…
at a size of about
27.4 million square
kilometres (size of
North America).
http://www.cbc.ca/news/world/story/2008/11/05/ozone-hole.html
35. Air Pollution Essentials
Atmospheric pollution (also commonly
called air pollution) is derived chiefly
from the spewing of gasses and solid
particulates into the atmosphere. Many
pollutants occur naturally, but most air
pollution is caused by human activity.
36. Air Pollutants – General Overview
A substance in the air that can cause
harm to humans and the environment is
known as an air pollutant. Pollutants
can be in the form of solid particles,
liquid droplets, or gases.
37. Air Pollutants – General Overview
Pollutants can be classified as primary or
secondary. Usually, primary pollutants are
directly emitted from a process, such as
ash from a volcanic eruption, the carbon
monoxide gas from a motor vehicle
exhaust or sulfur dioxide released from
factories. Secondary pollutants are not
emitted directly. Rather, they form in the air
when primary pollutants react or interact.
38. Air Pollutants – General Overview
An important example of a secondary
pollutant is ground level ozone — one of
the many secondary pollutants that make
up photochemical smog. Some pollutants
may be both primary and secondary: that
is, they are both emitted directly and
formed from other primary pollutants.
39. Atmospheric Pollution
Major Air Pollutants & Their Sources
In the last 200 years or so there appeared several
fundamental trends which became the major
forces behind the surge in levels of air pollution
throughout the globe. These are:
• Industrialization
• Population Growth
• Globalization
40. Major Air Pollutants
Industrialization
Among other things,
industrialization set in
motion the widespread use
of fossil fuels (oil, gas &
coal) which are now
the main pollution sources.
41. Major Air Pollutants
Population Growth
With population numbers literally
exploding around the world, the
demand for food and other goods
goes up. This demand is met by
expanded production and use of
natural resources, which in its
turn leads to higher levels
of environmental pollution in
general, and air pollution in
particular.
42. Major Air Pollutants
Globalization
Globalization has become an
effective facilitator of air pollution.
Developing countries usually have
much looser laws on environmental
protection. With this “benefit” as
well as the population growth and
easy availability of cheap labor, big
industry prefers to move its
facilities to such “pollution havens”
rather than work in more regulated
markets.
43. Atmospheric Pollution
More on Sources of Pollutants
Ozone (03)
Formed when reactive organic
gases (ROG) and nitrogen oxides
react in the presence of sunlight.
ROG sources include any source
that burns fuels, (e.g., gasoline,
natural gas, wood, oil) solvents,
petroleum processing and storage
and pesticides.
44. More on Sources of Pollutants
Respirable Particulate Matter (PM10)
Road Dust, Windblown Dust (Agriculture) and
Construction (Fireplaces). Also formed from
other pollutants (acid rain, NOx, SOx, organics).
Incomplete combustion of any fuel.
45. More on Sources of Pollutants
Carbon Monoxide (CO)
Any source that burns fuel such
as automobiles, trucks, heavy
construction equipment, farming
equipment and residential
heating.
46. More on Sources of Pollutants
Sulfur Dioxide (SO2)
Coal or Oil Burning
Power Plants and
Industries, Refineries,
Diesel Engines
47. More on Sources of Pollutants
Fine Particulate Matter (PM2.5)
Fuel Combustion in Motor Vehicles,
Equipment and Industrial Sources,
Residential and Agricultural Burning.
Also formed from reaction of other
pollutants (acid rain, NOx, SOx,
organics).
49. Acid Deposition
Acid deposition is a general name
for a number of phenomena, namely
acid rain, acid fog and acid mist.
This means it can imply both wet
and dry (gaseous) precipitation. Acid
deposition is a rather well
known environmental problem, for
example acid fog killed several
thousand people in London in 1952.
50. Acid Deposition
Acid deposition is concerned with long-range
rather than local effects. Pollutants are mixed in
the atmosphere and therefore usually cannot
be attributed to any local source. Pollutants are
generally more dispersed and of lower
concentrations than local ground level
pollutants.
51. Acid Deposition
Acid deposition
typically has a pH
below 4, but this may
be as low as 1.5
under seriously acidic
conditions. It primarily
consists of two types
of compounds,
namely sulphuric acid
(H2SO4) and nitric
acid (HNO3).
52. Acid Deposition
Sulphuric acid is
formed by conversion
of sulphur dioxide
emitted from power
stations, melting
processes, home
fires, car exhausts
and other sources. It
contributes about
70% to the overall
acidity of deposition.
Reaction mechanism:
SO3 + H2O -> H2SO4
53. Acid Deposition
Nitric acid is formed
from nitrogen oxide
(NOx) emissions
from fossil
fuel combustion. It
contributes about
30% to the overall
acidity of deposition.
Reaction mechanism:
NO2 + OH- -> HNO3
55. Impacts of Air Pollutants
The World Health
Organization states that 2.4
million people die each year
from causes directly
attributable to air pollution,
with 1.5 million of these
deaths attributable to indoor
air pollution.
56. Impacts of Air Pollutants
Because people are
exposed to so many
potentially dangerous
pollutants, it is often hard to
know exactly which
pollutants are responsible
for causing sickness. Also,
because a mixture of
different pollutants can
intensify sickness, it is often
difficult to isolate those
pollutants that are at fault.
57. Impacts of Air Pollutants
Many diseases could be
caused by air pollution
without their becoming
apparent for a long
time. Diseases such as
bronchitis, lung cancer, and
heart disease may all
eventually appear in people
exposed to air pollution.
58. Impacts of Air Pollutants
Older people are highly vulnerable to
diseases induced by air pollution. Those
with heart or lung disorders are under
additional risk. Children and infants are also
at serious risk.
59. Impacts of Air Pollutants
Air pollutants such as ozone, nitrogen
oxides, and sulfur dioxide also have harmful
effects on natural ecosystems. They can kill
plants and trees by destroying their leaves,
and can kill animals, especially fish in highly
polluted rivers.
61. Bringing Air Pollution Under Control
Two main types of pollution control
Input control involves preventing a
problem before it occurs, or at least
limiting the effects the process will
produce.
1
62. Bringing Air Pollution Under Control
Two main types of pollution control
Five major input control methods exist. People
may try to restrict population growth, use less
energy, improve energy efficiency, reduce
waste, and move to non-polluting renewable
forms of energy production. Also, automobile-produced
pollution can be decreased with highly
beneficial results.
Clean Air Act
63. Bringing Air Pollution Under Control
Two main types of pollution control
Output control, the opposite method,
seeks to fix the problems caused by air
pollution. This usually means cleaning
up an area that has been damaged by
pollution.
2
64. Bringing Air Pollution Under Control
Two main types of pollution control
Input controls are
usually more effective
than output
controls. Output
controls are also more
expensive, making them
less desirable to tax
payers and polluting
industries.
66. Coping with Acid Deposition
Short Term Method
Liming (calcium hydroxide) is one of the very
few ways to reduce the effects of acid rain.
This can only be a short-term method as
liming requires to be done regularly and that
will prove to be very costly. The only way to
stop acid rain is to reduce the amount of
acidic oxides released into the air.
67. Coping with Acid Deposition
Long Term Method
1. Reducing the use of fossil
fuels by using more public
transport and practicing
carpooling and using less of
cars but more of walking
and bicycles.
2. Using fossil fuels of low
sulphur contents
68. Coping with Acid Deposition
3. Extracting sulphur from the
existing fossil fuels before
using them. However, this
method might not be very
feasible, as it is very costly
to do so, especially at a
large scale.
Long Term Method
69. Coping with Acid Deposition
4. Using pollution control
equipment such as catalytic
converters in vehicles and
scrubbers in factories and
power stations and also
using the method of
desulphurisation.
Long Term Method
72. Unresolved Issues
• Expanded use of emissions trading for
pollutants other than SO2 ;
• The use and control of fuel additives,
including methyl tertiary butyl ether (MTBE);
• Sulfur removal from gasoline and diesel fuel;
• The interstate transport of NOx emissions;
• Regional haze; and
• Automobile emissions, especially issues concerning
the “right-to-know” and hazardous emissions from
coal-fired electric power plants.
73. Total World Electricity Generation
Source: IEA 2008
*Other includes solar, wind, combustible renewables, geothermal & waste
74. Unresolved Issues
Two broader policy issues that the nation must
deal with are:
1. The role of the developed and
developing nations in the control of
emissions of global warming
gases; and
2. The extent to which the
environment will be protected from
the effects of the deregulation of
the electric power generating
industry.
75. When I was a kid, we never heard of
smog, ozone depletion, acid rain,
green house gasses.
- Dennis Weaver
76. It's absolutely stupid that we live
without an ozone layer. We have
men, we've got rockets, we've got
saran wrap – FIX IT!
- Lewis Black
77. From a scientific perspective there is
some indication that a nuclear war could
deplete the earth's ozone layer or, less
likely, could bring on a new Ice Age - but
there is no suggestion that either the
created order or mankind would be
destroyed in the process.
- Herman Khan
78. So I'm going to go on and work on
preserving the ozone layer, encouraging
everyone to recycle.
- Dean Stockwell
79. Thank You
for
Listening!
Jovannie Espinosa
&
Markleen Guimbao
Hinweis der Redaktion
Nox – nirogen oxides; Sox – sulphur oxides
The pH scale measures how acidic or basic a substance is. It ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic, and a pH greater than 7 is basic.
Catalytic converter is a device in the exhaust system of a motor vehicle, containing a catalyst for converting pollutant gases into less harmful ones.
Emissions trading is a market-based approach used to control pollution by providing economic incentives for achieving reductions in the emissions of pollutants.
Regional haze has reduced scenic views in national parks and wilderness areas.