Carbon Cycle and Climate Change Flashcards
Energy balance of the Earth
Determined by the amount of solar radiation absorbed by the planet versus the amount radiated back into space.
Role of carbon in the atmosphere
Carbon dioxide and methane absorb long-wave radiation and trap heat
Carbon Cycle: Key processes
- Photosynthesis
- Respiration
- Decomposition
- Ocean uptake
- Fossil fuel combustion
Fast carbon cycle
Involves short-term processes like:
- Photosynthesis
- Respiration/Oxidation
- Ocean uptake/off-gassing
- Biodegradation
- Sedimentation
- Advection
Slow carbon cycle
Long-term geological processes:
- Weathering of rocks
- Ocean sedimentation
- Fossil fuel formation
- Volcanic eruptions
Coal formation
- Huge forests grew 300 million years ago covering most of the land
- The vegetation dies and forms peat
- Peat is compressed to form lignite
- Further compression forms bituminous coal
- Eventually anthracite forms
Natural gas and oil formation
- Marine plants and animals die and sink to the bottom of the seabed
- The plant and animal layer gets covered with mud
- Overtime, more sediment creates pressure, compressing the dead plants and animals into oil
- Oil moves up through the porous rocks and eventually forms a reservoir
Oil and natural gas extraction (4)
Conventional drilling
Fracking
Offshore drilling
Peak Oil
The point in time when the maximum rate of extraction of crude oil is reached, and after that the extraction is expected to enter final decline
Climate tipping points
Levels of climate change that trigger “large-scale discontinuities” in the climate system that commit the world to long-term irreversible change
What are the climate tipping points? (6)
Permafrost
Amazon
Coral reefs
Atlantic circulation
Ice sheets
Boreal forests
Permafrost tipping point
Melting ice facilitates mass decomposition of organic matter releasing massive amounts of methane.
Amazon tipping point
Drought causes enough forest loss to permanently reduce rainfall and shift to savanna
Coral reefs tipping point
Mass die-off from combination of heating, acidification, and pollution
Atlantic circulation
Melting Greenland ice sheet weakening flow of warm nutrient rich water to North Atlantic