1. 20
Global Climate Change

2. Climate Change Terminology
Greenhouse Gas
Gas that absorbs infrared radiation
Positive Feedback Loop
Change in some condition triggers a response that intensifies the changed condition
Infrared Radiation
Radiation that has a wavelength that is longer than that of visible light, but shorter than that of radio waves
Greenhouse Effect
Increase of heat in a system where energy enters (often as light), is absorbed as heat, and released sometime later

3. Climate Change (not global warming)
Refers to the recent and ongoing rise in global average temperature near Earth's surface
caused (mostly) by increasing concentrations of greenhouse gases in the atm.
significant change in climate lasting for an extended period of time
includes major changes in:
Temperature
Precipitation
Wind patterns
Occurring over several decades or longer

4. Greenhouse gases
Greenhouse gases act like a blanket around Earth, trapping energy in the atmosphere and causing it to warm

5. Increased concentration of CO2
Burning fossil fuels in cars, industry and homes
Deforestation
Burning of forests
Industrialization
This graph, based on the comparison of atmospheric samples contained in ice cores and more recent direct measurements, provides evidence that atmospheric CO2 has increased since the Industrial Revolution. (Source: NOAA)

6. CO2 accounts for 60% of increased heat retention
Greenhouse Effect
What we know
CO2 accounts for 60% of increased heat retention
Radiative Forces Capacity of gas to affect energy entering and leaving the atm

7. Introduction to Climate Change
Certain facts about climate are not in dispute
What we Know
CO2 has the ability to trap heat
Methane, Nitrous oxides, CFC’s tropospheric ozone can also trap heat
demonstrated in the mid-19th century
CO2 ability to capture infrared energy scientific basis of many instruments flown by NASA
Based on the knowledge above the following can be assumed
Increased levels of greenhouse gases must cause the Earth to warm in response

8. What we know Sea level rise Global temperature rise
Last 100 years rose ~6.7 inches
Last 10 years, rose ~12 inches
Global temperature rise
All major global surface temp reconstructions show that Earth has warmed since 1880.
Most of this warming has occurred since the 1970s
the 20 warmest years having occurred since 1981
and with all 10 of the warmest years occurring in the past 12 years

9. What we know Sciences evidence
Warming oceans
Oceans have absorbed much of this increased heat, with the top 2,300 feet of ocean showing warming of F since 1969
Shrinking ice sheets
Greenland & Antarctic ice sheets have decreased
Data from NASA's show
Greenland lost cubic miles of ice/year from
Antarctica lost 36 cubic miles of ice/year
Declining Arctic sea ice / Glacial retreat / Extreme events / Ocean acidification

10. Pollutants That Cool the Atmosphere
Atmospheric Aerosols - “ Aerosol Effect”
Both human and natural sources
Sulfur can remain in troposphere for weeks or months
Sulfur-laden haze in the atm reflects infrared radiation
Complicates models of climate change
Negative feedback loop
occurs when the result of a process influences the operation of the process itself in such a way as to reduce changes
One of the many complications that affects modeling climate change

11. Climate Models Climate affected by:
winds, clouds & ocean currents
Advanced models can project future warming events
Do there best to factor in all known data
Models are only as good as the data
Models have limitations

12. Effects of Global Climate Change - Melting Ice & Rising Sea Levels
IPCC – International Panel on Climate Change
Projects sea-level rise of cm by 2100
Projects temp to rise1.8 to 4.0ºC by 210
Sea level rise - 2 ways
Thermal Expansion
matter changes in volume in response to a change in temp
Melting of land ice
Melting has positive feedback
Increased melting decreases ice, which decreases albedo leading to further warming
(Albedo – Reflections from the a white surface)

13. Melting Ice & Rising Sea Levels
Thermal expansion
When water heats up, it expands
Melting of glaciers and polar ice caps
Large ice formations, like glaciers and the polar ice caps, naturally melt back a bit each summer.
Melting of surface ice
massive ice sheets that cover Greenland and Antarctica to melt at an accelerated pace
Consequences
Seawater reaches farther inland
destructive erosion, flooding of wetlands, contamination of aquifers & agricultural soils
lost habitat for fish, birds, and plants

14. Case-In-Point Impacts in Fragile Areas
Eskimo Inuit live traditional life
Alaska & Canada
Dictated by freezing climate
Climate change is altering their existence
Wildlife displaced
Reduced snow cover & shorter ice seasons
Thawing of permafrost
soil at or below the freezing
World-wide, permafrost contains huge amounts of dissolved carbon
The amount of carbon sequestered in permafrost is 4x the carbon that has been released to the atmosphere due to human activities in modern time

15. Effects of Global Climate Change- Changing Precipitation Patterns
Some areas will get more water, some areas will have greater droughts

16. Effects on Organisms - Coral Reefs
Coral reefs can be bleached due to increase in water temperature & increase in pH (Acidic)
Affects coral symbiotes & makes them more susceptible to diseases

17. Effects of Global Climate Change- Effects on Organisms
Zooplankton in parts of California Current have decreased by 80% since 1951
Affecting entire food chain
Species have shifted their geographic range
Migrating birds are returning to summer homes earlier
Ecosystems at greatest risk of species loss
coral reefs, mountain ecosystems, coastal wetlands, tundra, and polar spas

18. Effect on Organisms - Vegetation

19. Effects on Agriculture
Difficult to anticipate
Productivity may increase in some areas & decrease in others
Rise in sea level will inundate flood plains & river valleys
Effect on pests is unknown
Warmer temperatures will decrease soil moisture - requiring more irrigation
Location where certain crops can be grown may have to change

20. Effects of Global Climate Change
Extreme weather
More Wildfire in California
More extreme hurricanes

21. International Implications of Climate Change
Developed vs. Developing countries
Differing self-interests
Differing ability to meet the challenges of climate change

22. Dealing with Global Climate Change Two ways to manage climate change
Mitigation:
Limiting greenhouse gas emissions Locate/invent alternative fuels to fossil fuels
Increase efficiency of cars and trucks
Carbon Capture and Storage
Plant and Maintain trees to naturally sequester carbon
Adaptation:
Learning to live with environmental changes & societal consequences brought about by global climate change
Move inland (Rising sea levels)
Construct dikes and levees
Adapt to shifting agricultural zones

23. Relationship Between Mitigation & Adaptation

24. International Efforts to Reduce Greenhouse Gas Emission
Kyoto Protocol
Legally binding
Provides operational rules on reducing greenhouse gases
By 2010, 183 countries had ratified it
US has not sign it. The reason being…..
It did not require developing countries to make emission reductions
It would seriously harm the economy of the United States
Clinton signed it but the senate and house did not
It will be difficult to implement without US backing
EPA is taking it upon itself to define laws associated with CO2 reduction in US

25. Those that agree the climate is changing due to human influence
97% of Scientists
NASA
EPA (Environment protection agency) – of course
NIH (National Institute of Health)

26. Skeptics Modeling system are flawed
They do not take into account many factors
Can not predict the future
Do not have enough good recorded temp data
This could be just part of a large weather cycle that has not recorded (We have not been around long enough to record temp over thousands of years)
Aren't temperature changes natural?
Can't we wait and fix the climate if things get really bad

27. Interesting things on-line
You tube: Climate change way over simplified (but very interesting to think about)
the-global-warming-debate-completely-obsolete-7
As always know your source – all info is bias in one direction or the other. Do your best to get raw (not manipulated) data.