1. Climate Change: Fitting the pieces together
The topic of climate change is like a puzzle with many different pieces—oceans, the atmosphere, ecosystems, polar ice, natural and human influences. Scientists have been working on this puzzle for more than a century, and while there are still gaps in our knowledge, most experts feel we have the puzzle is complete enough to show that human activities are having an adverse effect on our planet. This talks looks at many of those puzzle pieces, the evidence behind them, and the conclusions we can draw from them. 1

2. Average weather conditions of the Earth or a particular area
Climate
Average weather conditions of the Earth or a particular area
Main focus: temperature & precipitation
Minimum period: 3 decades

3. Greenhouse Gases Gases that absorb and radiate heat
Major greenhouse gases
Methane
Nitrous oxide
Carbon dioxide
Water

4. Increasing greenhouse gases trap more heat
“Greenhouse effect”
Increasing greenhouse gases trap more heat
[Image 1] Earth’s surface absorbs heat from the sun and then re-radiates it back into the atmosphere and to space.
[click, Image 2] Much of this heat is absorbed by greenhouse gases, which then send the heat back to the surface, to other greenhouse gas molecules, or out to space. Though only 1% of atmospheric gases are greenhouse gases, they are extremely powerful heat trappers. By burning fossil fuels faster and faster, humans are effectively piling on more blankets, heating the planet so much and so quickly that it’s hard for Mother Nature and human societies to adapt. 4

5. Measuring Greenhouse Gases
Charles Keeling
Studied atmospheric CO2
Mountains in Hawaii
Far away from forest and cities

6. Carbon Dioxide Levels

8. Global Warming
A gradual increase in the average global temperature that is due to higher concentrations of greenhouse gases

9. Causes of Climate Change
Variation in the sun’s energy
Natural 11 year cycle (small)
Changes occurring in the sun itself can affect the intensity of the sunlight that reaches Earth’s surface. The intensity of the sunlight can cause either warming (during periods of stronger solar intensity) or cooling (during periods of weaker solar intensity). The sun follows a natural 11-year cycle of small ups and downs in intensity, but the effect on Earth’s climate is small.[1]

10. Causes of Climate Change
Variation in the sun’s energy
Changes in the Greenhouse affect
Decrease/Increase in Greenhouse gases

11. Greenhouse Gas Emissions
Water (H2O)
Evaporation
Transpiration
Steam from energy generation

12. Greenhouse Gas Emissions
Carbon Dioxide (CO2)
Volcanic Activity
Decomposition
Respiration
Ocean exchange
Industrial revolution
Burning fossil fuels (87%)
Deforestation
Agriculture

13. Greenhouse Gas Emissions
Methane (CH4) – 64 % anthropogenic
Wetland (anaerobic bacteria)
Burning or fracking for natural gas
Landfills
Permafrost melt
Agriculture (Beef)
% study in nature

14. Greenhouse Gas Emissions
Nitrous Oxide (N2O)
Soil microbes
Ocean microbes
Fertilizers
Manure & chemical
Burning of fossil fuels
Human sewage from septic tanks (bacteria)

15. Greenhouse Gas Emissions
Ground Level Ozone (troposphere)
Good in stratosphere – blocks UV
Produced from photochemical reactions with pollutants in the atmosphere

16. Greenhouse Gas Emissions
CFCs (Chlorofluorocarbons)
No natural source (created in 1928)
Refrigerants
Aerosols
Cleaning solvents
**destroy stratospheric ozone
**phased out in 1989 – Montreal Protocol

18. Effects on Earth Temperature Risen 1° in 100 years
Predict 1-2° more by 2050

19. Precipitation
Droughts
Flooding

20. Vulnerable ecosystems
Temperature changes
Migrations

21. Ocean Acidification Oceans is a major carbon reservoir
30% of anthropogenic C
Oceans are warmer
Holds less CO2
Ocean Acidity
Water + Carbon Dioxide = Carbonic Acid
30% increase in last 200 years

22. Rise in sea level Glacier melt Threatens small islands & coastal areas
Video in glacier pic

23. Loss of species
Video in polar bear pic

24. What do climate scientists really think?24