1. Greenhouse Effect and Global Warming

2. Greenhouse Effect
How we stay warm

3. The Sun’s energy reaches Earth through:
Radiation heat traveling through Space

4. What is Insolation? The incoming solar radiation (energy
from the Sun) that reaches Earth

5. How much solar radiation reaches Earth?
Earth’s surface only absorbs 51% of incoming solar radiation
In the atmosphere clouds account for the greatest absorption of radiation (19%)

6. Greenhouse Effect
The process by which gasses absorb heat energy from the sun and prevent heat from leaving our atmosphere.
In other words, greenhouse gases trap heat energy and keep it close to earth.

7. Greenhouse Gases Primary Secondary Water vapor Carbon dioxide Methane
Nitrous oxide
Ozone

8. Natural Greenhouse Gases
Volcanic eruptions- mainly carbon dioxide
Methane – from decomposition
Nitrous oxide- from denitrification
Water vapor

9. Anthropogenic (Man-made) Sources Greenhouse Gases
deforestation (CO2)
fossil fuel combustion (CO2)
cattle digestive gas emissions (methane)

10. Anthropogenic Sources Greenhouse Gases

11. Is the Greenhouse Effect Good or Bad?
It is necessary for life (good) when
it keeps our climate toasty warm and prevents it from fluctuating (changing) too much
It is bad when
there are too many greenhouse gasses and the climate gets warmer (GLOBAL WARMING)

12. What is Global Warming?
A theory that the Earth is gradually getting hotter an hotter.
It is caused by an increase in Greenhouse Gases in the Atmosphere
Global warming could lead to an increase in:
Hurricanes
Floods
Heat waves
Tornadoes

13. Temperature change over past 22,000 years
Agriculture established 1
Average temperature over past
10,000 years = 15°C (59°F) -1
End of
last ice
age
Temperature change (°C) -2 -3 -4 -5
20,000
10,000
2,000
1,000
200
100
Now
Years ago
22,000

14. Temperature change over past 1,000 years Temperature change (°C)
1.0
0.5
Temperature change (°C)
0.0
-0.5
-1.0
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2101
Year
1000

15. 130 years Average temperature over past 130 years 15.0 14.8 14.6 14.4
Average surface temperature (°C)
14.2
14.0
13.8
13.6
1860
1880
1900
1920
1940
1960
1980
2000
2020
Year
130 years

16. Natural Climate Variation
Natural factors affecting temperature
volcanic eruptions
variations in cloud cover
ocean currents
Evidence
ice core data
fossil record of species (plant & animal)

17. 5 Things that cause an Increase in Greenhouse gases
CARBON DIOXIDE
added to the atmosphere when people burn fossil fuels

18. 5 Things that cause an Increase in Greenhouse gases
Deforestation
increases the amount of carbon dioxide in the air because in photosynthesis plants take in carbon dioxide and remove it from the atmosphere, they make oxygen.

19. 5 Things that cause an Increase in Greenhouse gases
Volcanoes, fires, and respiration
add CO2 to the atmosphere
Carbon Cycle

20. 5 Things that cause an Increase in Greenhouse gases
Methane
produced when garbage is buried in landfills, from animal waste, and from other natural sources.

21. 5 Things that cause an Increase in Greenhouse gases
As temperatures increase
evaporation increases which adds water vapor