1. Lecture 15 (Review) Ocean’s Role in Climate and Climate Change by Instructor: Dr. Charles Dong at El Camino College

2. Questions? What are the ocean’s roles in the climate?
What kind of situation of the global climate are we facing now?
As an individual living on the earth village, what should we do to help stabilize the global climate change?

3. Ocean’s roles in Climate and Climate Change
The ocean acts as a global climate system
adjustor with its large heat capacity
2. The ocean acts as a global climate system by regulating the concentration of carbon dioxide (CO2) in the atmosphere.

4. Basic Facts of Earth’s Oceans
Cover 70.8% of Earth’s surface;
Huge size and volume, as a reservoir, contain 97% of Earth’s water;
Water has higher heat capacity than rocks (amount of energy to raise one gram of material 1 degree higher).

5. Ocean surface currents
Red lines carry warm water and blue lines carry cold water: it is noted that the warm water is carried to cold areas and cold water to warm areas

6. Coastal Moderate Climate
Solar heating
Different heat capacities of land and water
Sea breeze
From ocean to land
Land breeze
From land to ocean
Fig. 6.13

7. Exe. 16-01 List the two primary roles of ocean in the global climate
How does the oceanic circulation adjust the climate?
Why do the coastal areas have the moderate weather?

8. How a greenhouse works
Sunlight (visible and UV) passes through the clear covering of a greenhouse
It is converted to longer wavelength heat energy (IR)
Heat (and IR) cannot pass through the covering and is trapped inside
Fig. 6.24

9. Greenhouse gases in the atmosphere
Absorb longer wave radiation from Earth
Water vapor
Carbon dioxide (CO2)
Other trace gases: methane, nitrous oxide, ozone, and chlorofluorocarbons

10. The heating of Earth’s atmosphere

11. Earth’s average temperature is rising
Earth’s average surface temperature has risen at least 0.6°C (1.1°F) in the last 130 years
May be related to increase in atmospheric carbon dioxide
Arctic ice sheet breaking up
Glaciers throughout the world melting
Fig. 6-28

12. Carbon dioxide is increasing in the atmosphere
Fig. 6.27

13. Sea Ice Coverage Declines in Arctic Ocean
Sea ice extent reached a record
minimum in summer 2005, and the
past four summers ( ) has
been among the lowest on record.
Fig. 6.22

14. Global warming and changing sea level
About 0.6oC (1.1oF) warmer over last 130 years
Sea level rose cm (4-10 in) over past 100 years
If global warming continues, higher sea level due to water expansion and ice melting
Fig

15. Exe. 16-02 What is the major greenhouse gas due to human activities?
When did the global temperate start to increase sharply?
Why does the sea level rise with the global warming?

16. Ocean’s role in reducing the greenhouse effect
The oceans absorb vast amount of carbon dioxide from the atmosphere
What happens to the carbon dioxide that enters the ocean? Biological Pump (next slice)

17. Nutrient cycling: Photosynthesis, Biological Pump and Upwelling.
Fig

18. Possible consequences of global warming
Melting glaciers
Shift in species distribution
Warmer oceans
More frequent and more intense storms
Changes in deep ocean circulation
Shifts in areas of rain/drought
Rising sea level

19. Reducing greenhouse gases
Greater fuel efficiency
Alternative fuels
Re-forestation
Eliminate chlorofluorocarbons
Reduce CO2 emissions
Intergovernmental Panel on Climate Change (4 reports 2007 Nobel Peace Prize for IPCC)
Kyoto Protocol 1997
Copenhagen UN Climate Change Conference(ongoing)

20. Discussion
What should we do to help stabilize the climate change?