✅C&W 3.1.1.3 - The Carbon Cycle Flashcards
What is a Carbon store?
The lithosphere, hydrosphere, cryosphere, atmosphere etc
What is a carbon sink?
A store that takes in more carbon than it releases
What is a carbon source?
A store that releases more carbon than it takes in
What is a carbon transfer?
Processes that transfer carbon between stores
What is a GtC?
A gigatonne of Carbon, 1 gigatonne = 1 billion tonnes
What is anthropogenic CO2?
Carbon Dioxide generated by human activity
What is a greenhouse gas?
Any gaseous compound in the atmosphere that is capable of absorbing infrared radiation, therefore trapping and holding heat in the atmosphere
What is the lithosphere?
The crust and uppermost mantle, the hard rigid outer layer of the earth
Includes organic and inorganic carbon
organic carbon in the lithosphere
in soil- 1500 GtC
humus, litter
Medium residence time, 100 years in soil
Farming can disrupt stores, release Carbon
inorganic carbon lithosphere
Fossil fuel deposits, 4,100 GtC
Marine sediments and sedimentary rock- very long term, up to 100 million GtC- biggest store
Carbon in hydrosphere
up to 40,000 GtC in ocean
Living organic matter only 30GtC- significant but not major carbon release if killed due to warming
Sedimentary layer in ocean: organisms die, sink to bottom, decay, material forms rock over millions of years
What is weathering?
The breakdown of rocks in situ by weather, plants and animals
What is the biosphere?
The total sum of all living matter
What is Carbon Sequestration?
The capture of CO2 from the atmosphere, or capturing anthropogenic CO2 from large scale stationary sources such as power stations - put into long term storage
Why is recycling carbon essential for life?
It enables food to be provided for plants and animals and creation of energy sources
What can carbon form?
Biological molecules, Gases (eg CO2, CH4), Hydrocarbons
What is the primary source of Carbon?
The Earth’s interior
What are some of the stores in the carbon cycle?
Sedimentary rock, coal, oil, gas, plants, atmosphere, phytoplankton etc
What are some of the transfers in the carbon cycle?
Weathering and erosion, rock cycle, photosynthesis, respiration, burning, decomposition, diffusion
What is the largest store of carbon?
Marine sediments and sedimentary rock
How is the ocean a store of carbon?
CO2 is absorbed directly from the air and river water discharges carbon in solutions
How is soil organic matter a store of carbon?
They contain rotting organic matter and are important carbon stores. Carbon can remain in the soils for hundreds of years
How is carbon in the biosphere divided up?
How much GtC overall?
Into terrestrial and oceanic
3,100 GtC overall
What are the main sources of carbon in the biosphere?
Living vegetation- 19% of biosphere's carbon Plant litter Soil humus- in forests 69% of all C is in soil- 2500GtC Peat- saturation, no oxygen, decay is slowed due to anaerobic respiration, longer residence time- 250GtC Animals
Where is most of the carbon in the cryosphere?
In the soil areas of permafrost where decomposing plants and animals have frozen into the ground
What are methyl clathrates?
Molecules of methane frozen into ice crystals
What does most frozen organic matter in permafrost consist of?
Partially decayed roots, whole roots and other plant material
When is cryospheric carbon released into the atmosphere?
When the permafrost melts
What are oceanic carbon stores divided into?
Surface later (euphotic zone)
Intermediate and deep layer
Living organic matter