Global warming is caused by increasing greenhouse gas concentrations, especially CO2, trapping heat in the lower atmosphere. The main greenhouse gases are CO2, methane, nitrous oxide, CFCs, HFCs, PFCs and sulfur hexafluoride. GHG concentrations have increased substantially since the industrial revolution due to human activities like fossil fuel burning. If emissions continue rising, global temperatures are projected to increase 1-2°C by 2050, causing sea level rise, more extreme weather, and effects on ecosystems, agriculture, societies and economies around the world. India is particularly vulnerable due to increased flooding, droughts, cyclones and impacts on coastal areas.

1. Global warming and Climate change
Prepared by:
Veereshgouda. M. Police Patil

2. Contents
• What is global warming?
• Science behind Global Climate Change
• Green house effect
• GHG’s concentration
• Present and future trends in Global Climate Change
• Sources of Green House Gases
• Trends in Co2 emission
• Consequences of global climate change: World and India

3. What is global warming?
Global warming: Regular increase in
mean annual temperature of the
earth.
This is mainly because of increase in
concentration of GHGs in the
atmosphere (especially CO2)

4. 78% nitrogen
20.6% oxygen
< 1% argon
0.4% water vapor
0.036% carbon dioxide
traces gases:
Ne, He, Kr, H, O3
Methane, Nitrous Oxide

6. Science behind global warming
Green house effect
The green house gases - CO2 , methane, N2O, CFC, SF6, O3 (3-7%)
etc., absorb less of the insolation in atmosphere and much of the
outgoing long wave radiations. Thus, they retain the heat in the
atmosphere.
Results in
Uncomfortness
Diseases and deaths (Cancer, skin diseases etc)

7. The Green house gases
(GHGs) provide a
blanketing effect in the
lower strata of the earth’s
atmosphere, and this
blanketing effect is being
enhanced because of the
human activities like
burning of fossil fuels etc.

8. Greenhouse Effect & Global Warming
• The “greenhouse effect” & global warming are not the same
thing.
– Global warming refers to a rise in the temperature of the
surface of the earth.
i
• An increase in the concentration of greenhouse gases leads to
an increase in the the magnitude of the greenhouse effect.
(Called enhanced greenhouse effect)
– This results in global warming.

9. Green House Gas Inventory
Carbon di-oxide
CO2
Methane – CF4 Nitrous Oxide – N20
Perfluoromethane –
CF4
Sulphur
Hexafluoride – SF6
HCFC
CFC - 12

10. Emission trend of global green house gases
(www.unfccc.int)

11. Global warming potentials (GWP ) of Green House Gases
The main greenhouse gases
Green house
gases
Chemical
formula
Pre-
industrical
concentration
Conc. in
1994
Atm. life
time (years)
GWP
Carbon-
dioxide
CO2 278000 ppb 358000 ppb Variable
(Apprx.500)
1
Methane CH4 700 ppb 1721 ppb 12,2 +/- 3 21
Nitrous oxide N2O 275 ppb 311 ppb 120 310
CFC-12 CCL2F2 0 0503 ppb 102 6200-
7100
HCFC-22 CHCLF2 0 0105 ppb 121 1300 –
1400
Tetrachloroflu
oromethane
CF4 0 0070 ppb 50000 6500
Hexafluoride SF6 0 0032 ppb 32000 23900
UNITED NATIONS ENVIRONMENT PROGRAMME

12. 320
ppb380
ppm
1775
ppb
520
ppb
250
ppb
GHG’s concentration in atmosphere

13. Global Carbon Dioxide (CO2) emissions from fossil-fuels 1900-2008
Global carbon emissions from fossil fuels have significantly increased since
1900. Emissions increased by over 16 times between 1900 and 2008 and
by about 1.5 times between 1990 and 2008.

14. Sl.
No.
GHG Concentration Remark
1 Atm. CO2 390.5 ppm 40% greater than in
1750.
2 Atm. nitrous oxide (N2O) 324.2 ppb increased by 20% since
1750.
3 Atm. methane (CH4) 1803.2 ppb 150% greater than
before 1750.
4 Hydrofluorocarbons (HFCs),
Perfluorocarbons (PFCs)
and
Sulphur hexafluoride (SF6)
------ increased relatively
rapidly but their
contributions to
radiative forcing are less
than 1% of the total by
well-mixed GHGs
Present status of Direct GHG’s concentration (2011)
IPCC Assessment report 2013

15. Anthropogenic sources for GHG’s emission
Greenhouse gases Anthropogenic sources
Carbon-dioxide Fossil fuel combustion
Land use conversion
Cement production
Methane Fossil fuels
Rice paddies
Waste dumps
Livestock
Nitrous oxide Fertiliser industrial processes
combustion
CFC-12 Liquid coolants, Foams
HCFC-22 Liquid coolants
Tetrachlorofluoromethane Production of aluminium
Hexafluoride Dielectric fluid

16. Fossil fuel combustion Cement production
Land use conversion

17. Paddy field
Waste dumps
Livestock

18. Vehicular carbon emission

19. Global Greenhouse Gas Emissions by Source
1st
2nd
Land use change &

21. (www.unfccc.int)

22. Emission trend of global green house gases along regions
Highest carbon
emitter
(@ 1600 m MT
of C/yr)
5th place,
emits (@
700 m MT of
‘C’/yr)
(www.unfccc.int)

23. 2008 Global CO2 Emissions from Fossil Fuel Combustion and some Industrial
Processes of top countries

24. Consequences of global warming
• Melting of polar region
• Rise of sea level
• Effect on agriculture
• Human and animal Health
Impact of Global Warming on India
• Unseasonal rains
• Increasing Water Scarcity
• Lower Wheat Yields
• Increased incidence of heat waves
• Shrinking of Himalayan Glaciers

25. Consequences…
Effect on nature
Effect on society
Effect on glaciers
Effect on agriculture and fauna
Effect on forests

26. Consequences …
Effect on nature
In India 5 to 25% decline in winter rain fall, leading to
droughts during dry summer months
Increase in average summer monsoon rainfall over the
Indian subcontinent is only 10 to 15 per cent.
(Singh and Sonatakke, 2002)

27. Death of animals due to scarcity of water

28. Consequences contd…
Effect on society
Collapse of Maya civilization, (around 3000 years ago) on
Meso-America due to climate deterioration.
(Webster, 2002)
Collapse of Subir, (Around 300 AD agriculture civilization) of
Northern Mesopotamia in Syria.
(Weiss, 1993)

29. Consequences contd…
Indian Scenario
Almost all 335 glaciers in the
Sutlej, Beas and Spiti river
basins of Himachal pradesh
are receding because of global
warming.
(Sharma, 2001)
Overall prediction
By 2050, sea level
throughout the world will rise
by 21 cm.
(Anon, 1999)
Sea will rise by 18 cm in the
year 2020 and 58 cm by the
year 2090.
( Kumar, 2002)
Effect on glaciers

30. •Scary pictures of the northern polar regions in 1979 & 2005
•Polar ice has been decreasing by 1% per year since 1979.
1979 2005

31. Polar bear in struggle

32. Effect on Agriculture
Indian Scenario
At 0.5 o C increase in mean
temperature in Punjab,
Haryana and Uttar Pradesh
there would be a reduction in
productivity of wheat crop
by 10%.
(Samara and Sharma, 2002)
Overall prediction
Decline in yield of crop in
Latin America, from
Mexico to Argentina.

33. Predicted effects of climate change on agriculture by 2050
Climatic element Expected changes by
2050’s
Effects on agriculture
CO2 Increase from 360 ppm to
450 - 600 ppm
Good for crops: increased
photosynthesis; reduced water use
Sea level rise Increased in south and offset
in north by natural
subsistence/rebound
Loss of land, coastal erosion, flooding,
salinisation of groundwater
Temperature Rise by 1-2oC. Winters
warming more than
summers. Increased
frequency of heat waves
Faster, shorter, earlier growing seasons,
range moving north and to higher
altitudes, heat stress risk, increased
evapotranspiration
Precipitation Seasonal changes by ± 10% Impacts on drought risk' soil
workability, water logging irrigation
supply, transpiration
Storminess Increased wind speeds,
especially in north. More
intense rainfall events.
Lodging, soil erosion, reduced
infiltration of rainfall
Source: Climate change and Agriculture, MAFF (2000)

34. Possible benefits and drawbacks of global warming on agriculture, based on an illustration in
Scientific American, March, 1994

35. Consequences contd…
Indian Scenario
The Bengal tiger could
vanish
Effect on Fauna
Overall prediction
Central American Quetzal
bird could disappear.
Other animals that could
vanish around the world are
Polar Bear, Penguins and the
central African Mountain
Gorilla.
(Anon, 2001)

36. Effect on fauna contd…
Polar bear
Penguin
Bengal tiger

37. American Quetzal bird
African Mountain Gorilla

38. Consequences contd…
Effect on forests
Shift of species: 1oC rise in temperature will displace the limits
of tolerance of land species some 125 km towards the pole
or 150 m vertically on mountains.
(Anon, 1999)

39. Consequences contd…
Effect on insect-pest incidence:
Increase in temperature leads to:
• Accelerate to breeding population of insects resulting in more
generation per year
(Hedden, 1987)

40. Impacts of global warming on climate of India
• India is already a disaster prone area, with the statistics of 27
out of 35 states and Union territories being disaster prone,
with most disasters being water related.
• According to surveys, in the year 2007-2008, India ranked the
third highest in the world regarding the number of significant
disasters, with 18 such events in one year, resulting in the
death of 1103 people due to these catastrophes.

41. Catastrophes of climate change in India
• Floods
• Droughts
• Cyclones
• Effects on the sea and coastal areas

42. Floods in India
• Approximately 40 million hectares of the land is vulnerable to
floods, with 8 million hectares affected by it.
• A temperature increase of 2 °C in India is projected to displace
seven million people, with a submersion of the major cities of
India like Mumbai and Chennai.

43. Droughts
• Of the total agricultural land in India, about 68% is prone to
drought of which 33% is chronically drought prone, receiving
rainfall of less than 750mm per year.
• The World Record Of Drought Was In 2000 in Rajasthan, India.

44. Cyclones
• As a result of global warming, the average number of
hurricanes per year has increased over the past 30 years.
• The notable cyclones in Indian history include the 1737
Calcutta cyclone and 1970 Bhola cyclone, which affected more
than a million people.

45. Effects on the sea and coastal areas
• A one meter sea level rise is projected to displace
approximately 7.1 million people in India and about 5,764 Km2
of land area will be lost, along with 4200 Km of road.
• The effects of global warming have also caused damage to
coastal infrastructure, aquaculture and coastal tourism. The
aquatic ecosystems such as mangroves, coral reefs and grass
lands have also been affected by the climatic change.