3.1.1.3 The carbon cycle Flashcards
(20 cards)
What is a carbon sink?
A store that absorbs more carbon then it releases ie a forest
What is a carbon source?
Releases more carbon then it stores
What % of total global carbon is stored in lithosphere?
99.985% ie limestone
What % of carbon stored in biosphere?
0.0012%
What is ocean uptake and loss?
When carbon dioxide is directly dissolved and taken in by the ocean.
Outline the role of weathering in the carbon cycle (4)
1) Weathering is the break down of rocks on the surface.
2) This happens when the carbon dioxide in the atmosphere is absorbed by rainwater to form weak carbonic acid.
3) H2O + CO2 = H2CO3
4)Dissolved ions of elements such as potassium and magnesium are transported to the oceans
How do Ocean carbon pumps work?
Carbon dioxide dissolves in ocean waters
Cold polar waters can dissolve more then warmer equatorial waters.As water moves from the tropic to the poles the water gets colder meaning more carbon dioxide can be dissolved.
What is decomposition?
Decomposition includes physical, chemical and biological mechanisms and processes that break down organic matter. Decomposers break down the dead organisms and return the carbon in their bodies to the atmosphere as carbon dioxide by respiration.
6 processes for global carbon cycle ?
combustion
respiration
photosynthesis
ocean water pump
weathering
Decomposition
Natural climate changes; Orbital changes
Eccentricity?
Orbit changes from circular to elliptical
Every 100,000 years
elliptical orbits are more extreme weathers so hotter summers and cooler winters as the distance increases and decreases
How do wildfires happen?
Due to the build up of dry litter that are ignited by lighting strikes
How does climate change affect wildfires?
Warmer local and global temperatures increase evaporation, which means the atmosphere draws more moisture from soils, making the land drier.
A warmer climate also leads to earlier snowmelt, which causes soils to be drier for longer. And dry soils become more susceptible to fire
How does volcanic activity affect solar radiation
Sulfure is ejected which can reflect solar radiation
co2 is also released but is not large enough to cause warming
Since sulfure dioxide and huge amounts of dust is released they combine together with water in the atmosphere to create sulphuric acid. This acid together with dust reflect solar radiation back into space.
How does deciduous tree vary in seasons in correlation with the carbon budget?
Carbon budget may reverse as Photosynthesis would decrease significantly and lose their leaves in autumn.
System will slow down and include decay of litter due to lower temperatures at which decomposers are less efficient
what % does deforestation account for anthropogenic carbon emissions?
10%
One way the ocean takes carbon dioxide?
Carbon is converted into calcium carbonate which is used by some Marine organisms to build shells
Explain how the enhance greenhouse effect works?
1)The sun emits solar radiation to each
2) some of the energy is reflected back into space due to dust or clouds
3)The solar energy is converted to heat at earths surface
4) Long wave radiation is reflected from the earth surface to the atmosphere
5) Greenhouse gasses absorb it
6)some IR radiation escapes
7) human activities exacerbates absorption of IR leading to anthropogenic warming
What is carbon fertilisation
The limit of which is reached when the availably of water and nutrients are reached
What is the thermohaline circulation?
1) As water moves northward towards the higher latitudes it both cools and increases in salt content as salt is ejected in the formation of sea ice
2)Saltier and cold water is denser and drops into the deep ocean
3)This water moves along the depths until it can rise to the surface near the equator
4) Heat from the sun then warms the cold water at the surface and evaporation leaves the water saltier
5) The warm salty water is carried northward where it joins gulf stream
6) The warm salty water travels up the east coast then releases heat and warms up Western Europe
