Day 9 Carbon Cycle

Essential element to all living things

carbon

Sources

regions that supply carbon to organisms

Sinks

regions that store carbon, making it unavailable to organisms

Major abiotic carbon sources

1. atmospheric carbon dioxide (CO2)

2. oceanic bicarbonate ion (HCO3-)

Carbon form in biotic systems

reduced forms

Biotic carbon

1. sugars

2. fats

3. proteins

How carbon enters ocean

oceanic buffering

CO2 + H2O —> H+ + HCO3=

How carbon is added to air

1. burning fossil and non-fossil fuels

2. metabolism/respiration

C6H12O6 —> 6CO2 + 6H2O

How carbon is removed from air

1. photosynthesis

6CO2 + 6H2O —> C6H12O6

Carbon sinks examples

1. coal formed from woody remains of terrestrial plants

2. oil formed from beds of dead plankton

3. other compounds like calcium bicarbonate

Estimate stores in fossil fuels

4000 - 5000 gigatons

Estimate stores in dead biomass

1000 - 1500 gigatons

Estiate stores in inorganic carbon in ocean

37000 gigatons

Estimate biomass in terrestrial

600 - 1000 gigatons

Estimate biomass in oceanic

1000 gigatons

Major greenhouse gases

1. water

2. CO2

3. methane

How earth absorbs energy

absorbs energy from the sun

• gains heat as IR radiation

• greenhouse gasses reflect the heat back towards earth

Effect of increasing CO2

it’s a greenhouse gas so increasing CO2 will cause the average global temps to increase

Difference between climate change and global warming

Climate change includes

1. regional difference in temp change and temp variability

2. changes in precipitation amounts and patterns, air and water currents, etc.

What experts say climate change is driven by

97% of climatologists and atmospheric scientists believe climate change is driven mainly by human activities

Weather

conditions at a certain time

Climate

average weather across extended periods of time

Physical effects of climate change

1. increased temperature

2. changing precipitation patterns

3. increase violent weather

4. increase sea level

5. increase acidification of oceans

6. loss of glaciers and sea ice

Biological effects of climate change

1. changes in geographic distributions

2. decrease in population size

3. extinctions

How sea level is changing and how

Sea level is rising

• half from thermal expansion

• other half from ice melt

Why glaciers are important

glacier melt is important source of water in thesummer

Climate change effect of glacier size

glaciers are decreasing in size

Effect of ocean warming and acidification

warming and acidification cause coral to eject their symbiotic algal cells, causing imminent death of the coral

coral bleaching

Coral bleaching

coral eject their symbiotic algal cells, causing imminent death of the coral due to acidification and warming of oceans

Climate change effect on distribution of copepods

cold-water copepods have a reduced range in the North Atlantic 

• less cold water for them to live in

Tipping point

a critical point may be reached that causes a dramatic shift in global climate

tipping points are an example of 

positive feedback loop

example of positive feedback loop

release of methane from melting permafrost

Recovery from tipping points

is much more difficult

Climate change effect of Pied Flycatchers

1. Pied flycatchers feed heavily on caterpillars during nesting seasons

2. They base their nesting seasons based on day length

3. The caterpillar’s life cycle is based on temperature

4. As average temp increases, flycatcher nesting is no longer coordinated with peak caterpillar activity