Measures of Central Tendency: Mean, Median and Mode
Global warming
1.
2. Acknowledgement:
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author gratefully acknowledges the same. Any
objections to the use of internet resources may
please be indicated to suddurocks@yahoo.in so that
the same can be removed from the illustrations
used in this file.
This presentation is created with the sole intention
of benefitting a large number of student
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commercial purpose.
3. Contents :
About Global Warming
Causes of Global Warming
Effects of Global Warming
Facts of Global warming
Prevention of Global Warming
Some Interesting Pictures
4. About Global Warming
Global Warming is the increase in the
average temperature of the earth’s
atmosphere due to greenhouse
gases such as carbon dioxide.
5. According to the 2007 Fourth Assessment
Report by the Intergovernmental Panel on
Climate Change (IPCC), global surface
temperature increased 0.74 ± 0.18 °C
(1.33 ± 0.32 °F) during the 20th century.
6. Most of the observed temperature
increase since the middle of the 20th
century has been caused by increasing
concentrations of greenhouse gases,
which result from human activity such as
the burning of fossil fuel and deforestation.
7. Global dimming, a result of increasing
concentrations of atmospheric aerosols
that block sunlight from reaching the
surface, has partially countered the effects
of warming induced by greenhouse gases.
8. Climate model projections summarized in
the latest IPCC report indicate that the
global surface temperature is likely to rise
a further 1.1 to 6.4 °C (2.0 to 11.5 °F)
during the 21st century.
9. • The uncertainty in this estimate arises
from the use of models with differing
sensitivity to greenhouse gas
concentrations and the use of differing
estimates of future greenhouse gas
emissions.
10. ► Anincrease in global temperature will
cause sea levels to rise and will change
the amount and pattern of precipitation,
probably including expansion of
subtropical deserts.
11. ► Warming is expected to be strongest in
the Arctic and would be associated with
continuing retreat of glaciers, permafrost
and sea ice.
12. Other likely effects include changes in the
frequency and intensity of extreme
weather events, species extinctions, and
changes in agricultural yields.
13. Warming and related changes will vary
from region to region around the globe,
though the nature of these regional
variations is uncertain.
14. As a result of contemporary increases in
atmospheric carbon dioxide, the oceans
have become more acidic, a result that is
predicted to continue.
15. The scientific consensus is that
anthropogenic global warming is
occurring.
16. Nevertheless, political and public debate
continues.
17. The Kyoto Protocol is aimed at stabilizing
greenhouse gas concentration to prevent a
"dangerous anthropogenic interference".
18. As of November 2009, 187 states had signed
and ratified the protocol.
19. Causes of Global Warming
Scientists have spent decades
figuring out what is causing global
warming.
20. They've looked at the natural cycles and
events that are known to influence climate.
21. But the amount and pattern of warming
that's been measured can't be explained
by these factors alone.
22. The only way to explain the pattern is to
include the effect of greenhouse gases
(GHGs) emitted by humans.
23. To bring all this information together, the
United Nations formed a group of
scientists called the International Panel on
Climate Change, or IPCC.
24. • The IPCC meets every few years to review
the latest scientific findings and write a
report summarizing all that is known about
global warming.
25. ► Each report represents a consensus, or
agreement, among hundreds of leading
scientists.
26. ► One of the first things scientists learned is
that there are several greenhouse gases
responsible for warming, and humans emit
them in a variety of ways.
27. Most come from the combustion of fossil
fuels in cars, factories and electricity
production. The gas responsible for the
most warming is carbon dioxide.
28. Other contributors include methane
released from landfills and agriculture,
nitrous oxide from fertilizers, gases used
for refrigeration and industrial processes,
and the loss of forests that would
otherwise store CO2.
29. Different greenhouse gases have very
different heat-trapping abilities.
30. Some of them can even trap more heat
than CO2.
31. A molecule of methane produces more
than 20 times the warming of a molecule
of CO2.
32. Nitrous oxide is 300 times more powerful than
CO2.
33. Other gases, such as chlorofluorocarbons
(CFC’s) have heat-trapping potential thousands
of times greater than CO2.
34. But because their concentrations are
much lower than CO2, none of these
gases adds as much warmth to the
atmosphere as CO2 does.
35. In order to understand the effects of all the
gases together, scientists tend to talk
about all greenhouse gases in terms of the
equivalent amount of CO2.
36. Since 1990, yearly emissions have gone
up by about 6 billion metric tons of "carbon
dioxide equivalent" worldwide, more than a
20% increase.
37. Effects of Global Warming
The planet is warming, from North Pole to
South Pole, and everywhere in between.
38. Globally, the mercury is already up more
than 1 degree Fahrenheit (0.8 degree
Celsius), and even more in sensitive polar
regions.
39. • And the effects of rising temperatures
aren’t waiting for some far-flung future.
40. ► They’re happening right now. Signs are
appearing all over, and some of them are
surprising.
41. ► The heat is not only melting glaciers and
sea ice, it’s also shifting precipitation
patterns and setting animals on the move.
42. Some impacts from increasing
temperatures are already happening.
43. Ice is melting worldwide, especially at the
Earth’s poles.
44. This includes mountain glaciers, ice sheets
covering West Antarctica and Greenland,
and Arctic sea ice.
45. Researcher Bill Fraser has tracked the
decline of the Adeline penguins on
Antarctica, where their numbers have
fallen from 32,000 breeding pairs to
11,000 in 30 years.
46. Sea level rise became faster over the last
century. Some butterflies, foxes, and
alpine plants have moved farther north or
to higher, cooler areas.
47. Precipitation (rain and snowfall) has increased
across the globe, on average.
48. Spruce bark beetles have boomed in Alaska
thanks to 20 years of warm summers.
49. The insects have chewed up 4 million
acres of spruce trees. Other effects
could happen later this century, if
warming continues.
50. 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 8 inches (10 to 20 centimeters).
52. Species that depend on one another may
become out of sync. For example, plants
could bloom earlier than their pollinating
insects become active.
53. 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.
55. • 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.
56. ► Some diseases will spread, such as
malaria carried by mosquitoes.
57. ► Ecosystems will change—some species will
move farther north or become more
successful; others won’t be able to move
and could become extinct.
58. Wildlife research scientist Martin 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.
59. 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.
60. Facts of Global Warming
Climate change is observed worldwide.
Average temperature of earth has
increased by 0.8 degrees since last 100
years.
61. Higher levels of CO2 have caused ocean
acidification.
62. Most of the densely populated Low lying
coastal regions are more vulnerable to
climate shifts.
63. Winter of 2003-2004 was the 33rd coldest in the
North Eastern America since the records began
in 1896.
64. Prevention of Global Warming
Drive less. Take bikes, walk or carpool
whenever possible.
65. Consider investing in a hybrid or
electric vehicle to help prevent
against further global warming.
66. Replace all the light bulbs in and around
your home with energy-efficient
fluorescents that use fewer watts for the
same amount of light.
81. Shop locally for food. A farmer’s market is
an excellent place to visit. And choose
fresh food over frozen foods. Fresh takes
less energy to produce.
82. Keep your car tuned up, and check tire
pressure often to save gas.
83. Eat less meat and more organic foods in
your diet to do your part in preventing
global warming.
