This document discusses global warming and the greenhouse effect. It explains that human activity is increasing greenhouse gases which thickens the layer trapping heat in the atmosphere and gradually increases earth's temperature. The greenhouse effect was discovered in 1824 and the main greenhouse gases are carbon dioxide, methane, CFCs and nitrous oxide. These gases are essential for maintaining a habitable temperature on Earth but human activities like burning fossil fuels have increased their levels since the pre-industrial era. This warming effects ecosystems and humans in various ways like rising sea levels and more extreme weather. Solutions proposed to reduce global warming include using renewable energy, afforestation, energy efficiency and international agreements like the Kyoto Protocol.

1. GLOBEL WARMING AND
GREEN HOUSE EFFECT
VIPIN MOHAN
2011-09-112
College of Agriculture
Vellayani, TVM

2. GLOBAL WARMING!
• Human activity is adding more
gases to the naturally occurring
layer of greenhouse gases. This
thickens it so it cannot let as much
heat return to space and so the
temperature of the earth gradually
increases……

3. GLOBEL WARMING IS CAUSED BY GREEN HOUSE EFFECT

4. Who found the greenhouse effect?
The greenhouse effect was discovered by
Joseph Fourier in 1824.

5. Our earth is surrounded by a layer of
gases called greenhouse gases.
There job is to keep the planet at a nice
warm temperature.
The main gases that make us this layer
are carbon dioxide, methane, CFC and
nitrous oxide.
This layer of gas acts like the roof of a
greenhouse and that is why it is called the
“Greenhouse effect”.

6. Mars
Atmosphere: mass <1% earth’s
GH Gases: >80% CO2
Sfc. Temp.: -47C
GH Effect: 10C
FAR TOO COLD!
Other planets also have Greenhouse Effects,
but these are unsuitable for life
Earth
GH Gases: ~0.04% CO2
~ 1% H2O
Sfc. Temp.: 15C
GH Effect: 33C
NOT BAD!
Venus
Atmosphere: mass 90x
earth’s
GH Gases: >90% CO2
Sfc. Temp.: 477C
GH Effect: 523C
FAR TOO HOT!
Sun

8. Greenhouse gases
 Greenhouse gases are the gases present in the
atmosphere which reduce the loss of heat into space
and therefore contribute to global temperatures.
Greenhouse gases are essential to maintaining the
temperature of the earth.
The term greenhouse gas is applied to, in order of
relative abundance: water vapour, carbon dioxide,
methane, nitrous oxide, ozone and CFCs.
•

9. Name of gas Contribution Source(s)
Carbon dioxide
(CO2)
50% From burning coal and oil, and the removal of
vegetation
Chlorofluorocarbons
(CFCs)
20% From air conditioners, refrigerators and aerosols
Methane
(CH4)
16% From rice growing, animal waste, swamps and
landfills
Ozone
(O3)
8% From air pollution
Nitrous oxide
(N2O)
6% From fertilizers and burning of coal and oil

11. Human activities have changed the
composition of the atmosphere since the
pre- industrial era

12. Characteristics of GHG
• Atmospheric life time.
• Global warming potential.
• Atmospheric concentration.

13. So where are these gases coming from?
Power stations release huge
amounts of carbon dioxide as
they burn coal (a fossil fuel) in
order to produce electricity.

14. Greenhouse Gas Emissions
Power Plants
40% of carbon dioxide emissions stem from the burning of fossil fuels for the purpose of
electricity generation
Cars
20% of carbon dioxide emissions comes from the burning of gasoline in internal-
combustion engines of cars and light trucks with poor gas mileage contribute the most to
global warming
Trucks
Another 13% of carbon dioxide emissions come from
trucks used mostly for commercial purposes
Airplanes
Aviation causes 3.5 percent of global warming,
and the figure could rise to 15 percent by 2050
Carbon Dioxide from Buildings
Buildings structure account for about 12% of
carbon dioxide emissions

15. CAUSES OF GREEN HOUSEEFFECT
• Deforestation.
• Emissionsofgases like nitrous oxide, carbon-dioxide,
methane, ozone and water vapor.
• Burningof fossilfuels, gasoline,oil
• Burning of woodandcoal
• CFC’s
• PopulationGrowth

16. • Global Warming
• Endangered Species
• Climate Change

17. Impacts of Global Warming
- physical
• Later freezing and
earlier break up of
river and lake ice
• Sea level rise
• Higher incidence of
floods and droughts
in some regions

18. Impacts of Global Warming
- biological
• Longer growing seasons
• Poleward and altitude shifts of
plants and animal ranges
• Decline of some plant and animal
population ( Drive 15 - 37% of
living species toward extinction
by the middle of the century)
• Early tree flowering, emergence
of insects and birds eggs laying
• Damage to natural systems
Many of these impacts are
irreversible

19. Impacts of Global Warming
- human system
Systems at risk include:
• water resources
• Agriculture and forestry
• Coastal zones and marine
systems
• Decreasing water availability
in regions where water is
already scarce
• Human health and risk of
disease

20. polar bears and globel warming
• Natural habitat loss
• Reproduction related problem
• Swimming conditions become
problematic
• Inability to catch prey

21. There are also some positive effects of
global warming
• Decrease in death and disease
• Healthier, faster growing forests due to excess
CO2
• reduce cold-related deaths and help crop growth.
• Warmer temperatures (UK Mediterranean
climate!!)
• Plants and shrubs will be able to grow further
north and in present desert conditions
• Heavier rainfall in certain locations will give higher
agricultural production (Rice in India, Wheat in
Africa).

22. How can Global Warming be reduced?
• Reduce the use of fossil fuels. A major impact
would be to find alternatives to coal, oil and gas
power stations.
• Afforest areas, trees use up the CO2, reduce
deforestation.
• Reduce the reliance on the car (promote shared
public transport).
• Try to use energy efficiently (turn off lights and
not use as much!).
• Reduce, Reuse, Recycle.
• Careful long term planning to reduce the impact of
global warming.

23. 1.Reduce electricity use.
2.Use ecofriendly vehicles.
3.Reforestation
4.Personal Actions
5.Climate Policy

24. What Can be Done: Alternatives
Renewable Energy Sources
Solar Energies Wind Power Biomass Geothermal
Changes In Vehicle Systems
Hybrid Fuel Cell Battery-
Electric

25. Kyoto Protocol
• 1997, Kyoto, Japan  developed countries
agreed to specific targets for cutting their
emissions of greenhouse gases
• Industrialized countries committed to an
overall reduction of emissions of greenhouse
gases to 5.2% below 1990 levels for the period
2008 - 2012
• Objective is the stabilization of greenhouse gas
concentrations in the atmosphere at a level that
would prevent dangerous anthropogenic
interference with the climate system

26. So what will you do
?

28. Thank
you