4. Why is CO 2 accumulating in the atmosphere and what can be done about it ?

5. Questions to consider: 1.Explain the annual periodicity of the above curve? 2.What inferences can you make about CO2 concentrations for the next 50 years ? The graph below shows carbon dioxide concentrations in the atmosphere in parts per million (ppm) from 1958 until the present.

6. ATMOSPHERIC CO 2 Stored CO 2 – Fossil Fuels Human use Process Direct Air to Sea Exchange (dissolution) Process Plants and Animals Oceans Process 1. Review Processes

7. Basic principle: Accumulation happens when inputs are greater than outputs For carbon cycle: -Inputs to atmosphere = sources -Outputs from atmosphere = sinks (land and ocean)

8. 120 70 Oil Oceans Human Fuels The atmosphere Coal Natural Gas 0 Before human civilization... Plants, animals and soil

9. 1211229092 Plants, animals and soil Oil Oceans Human Fuels The atmosphere Coal Natural Gas 7 In the year 2005 1 Gt/yr from deforestation More CO 2 dissolved in oceans 2 Gt/yr from regrowth of forests

10. 9092 Oil Oceans Human Fuels The atmosphere Coal Natural Gas What numbers must be present in the empty boxes to make the movement of carbon into and out of the atmosphere balance? Plants, animals and soil

11. 9092 Oil Oceans Human Fuels The atmosphere Coal Natural Gas 122 120 4 4 Reduce deforestation Maintain regrowth of forests Reduce emissions from energy use One possible solution Plants, animals and soil

12. Movement of Carbon in every year during the years 2020 - 2030 Figure 4. This shows the concentration of carbon dioxide in the atmosphere in parts per million (ppm) if levels are stabilized by 2020. Figure 3. This shows the movement of carbon in every year for the years 2020 – 2030. The numbers stand for billions of tons of carbon. Concentration stabilization scenario 1224

13. Challenge #1 - How to make this fun, relevant, and not depressing

14. CO 2 electricity

15. materials Sustainability will provide new opportunities Understanding how the earth works and how humans fit in is cool You are not a bad person if you drive a car; you are just a contemporary human. What will a future human drive? There will still be electric guitars in the future. Individual behavior matters. Collective behavior matters more. We will figure this out. Enjoy the ride. Be part of it.

16. Challenge #2 Finding Solutions  How can we stabilize carbon emissions over the next 50 years to maintain Carbon emissions instead of continuing on our current path? http://cmi.princeton.edu/wedges/slides.php