1. The carbon cycle
Human Impacts

2. Image from http://www. physicalgeography

3. The Overall trend: why the fluctuations?
Seasonal variations
in photosynthetic activity

4. Image from http://climate.nasa.gov/evidence/

5. Greenhouse effect vs climate change
The greenhouse effect helps trap infrared energy (heat) in our atmosphere – needed for life on Earth
Climate change is what happens when too many greenhouse gases have accumulated in the atmosphere, causing unnatural changes
CO2, CH4 (methane), and CF4 (carbon tertraflouride-the most potent and longest-lived) are carbon-containing greenhouse gases
Others include nitrous oxide, ozone, and water vapor

6. Image from http://www.eia.gov/oiaf/1605/ggccebro/chapter1.html

7. What do we do to affect the carbon cycle?
Burn fossil fuels (coal, oil, gas)
Destroy carbon sinks through actions like deforestation, slash and burn agriculture (turning forests into fields), using peat for fuel
These lead to
Increase in mean annual global temperatures (about 0.5° C in the last century)
Melting of glaciers and a rise in sea-level
Melting of frozen underwater methane stores—potentially very bad, since methane is a potent greenhouse gas
Ocean acidification

8. Ocean acidification
As you saw in the video, acidification can lead to:
Loss of marine biodiversity
Far-reaching effects in the food web
The possible death of phytoplankton (earth’s largest carbon sink)

9. More than one problem…
Acidic waters dissolve calcium carbonate shells, but
THEN, bicarbonate is formed, which can’t be taken in by these organisms
So not only are their shells dissolving, but it’s harder to repair the damage