1. Photosynthesis
The Big Picture

2. Carbon cycle
 Process by which carbon moves from organic
to inorganic compounds and back
 Producers convert inorganic carbon (CO2) into
organic carbon compounds (glucose)
 Primary Consumers obtain organic compounds
by eating producers
 Secondary consumers obtain organic carbon
by eating primary consumers
 Cellular Respiration by producers and
consumers return CO2 to atmosphere

3.  In the natural carbon cycle, there are two
main processes which occur
 Photosynthesis
 Metabolism/Cellular Respiration

8. Carbon in Ocean and
Sediments
 CO2 is slightly soluble
 Can be absorbed into water
 Some of the dissolved CO2 remains in the water, the warmer the water the
less carbon dioxide remains in the water
 Some CO2 is used by algae and phytoplankton through the process of
photosynthesis
 Coral and shelled marine organisms take up CO2 from the water and
convert it into calcium carbonate
 When these organisms die pieces of shells/coral fall to ocean floor and make
sediments
 The carbonate sediments are constantly being formed and redissolved in the
bottom of the ocean
 Over long periods of time, the sediments may be raised up as dry land or
into mountains
 This type of sedimentary rock is called limestone
 The carbonates can redissolve releasing carbon dioxide back to the air or
water

11. Humans and the Carbon
Cycle
 Combustion of any type of fossil fuel, which may
include oil, coal, or natural gas
 Fossil Fuels formed thousands of years ago from
plant or animal remains that were buried,
compressed, and transformed into oil, coal, or
natural gas
 This carbon is said to be "fixed" in place and is
essentially locked out of the natural carbon cycle
 Humans intervene during by burning the fossil fuels
 During combustion in the presence of O2, CO2 and water
molecules are released into the atmosphere

12. Photosynthesis and Global
Climate
 CO2 makes up 0.03 percent of Earth’s atmosphere
 300 parts per million
 Greenhouse Effect
 CO2 traps heat from sun in Earth’s atmosphere (otherwise it would escape into space)
 Not a bad thing
 Keeps world climate warm enough to sustain life
 Keeps Earth 10% warmer than it would be without CO2
 Currently CO2 in atmosphere is rising
 360 parts per million
 Burning fossil fuels
 Deforestation
 Natural Causes
 Photosynthesis
 Cellular respiration
 Decomposition
 Volcanic eruptions
 Ocean/limestone
 Global Warming
 Overall rise in Earth’s average temperature over a period of time