Carbon Stores

Question 1

Soil (lithosphere)

Answer 1

• soils contain rotting organic matter and weathered rock are important long term stores of carbon - it can be stored for 100s of years
• deforestation, land use changes and soil erosion can, however, release this stored carbon quickly

Question 2

Rocks (lithosphere)

Answer 2

• largest store. long term store, with rocks taking millions of years to form
• rocks such as chalk and limestone are mainly composed of carbon (fossilised remains of marine animals)
• fossilised organic matter is also trapped within the lithosphere, stored in coal, oil and natural gas

Question 3

Living vegetation (biosphere)

Answer 3

• plants convert energy from the sun into carbohydrates that support life
• plants can store carbon for many years and transfer it to the soil, ocean, seabed or atmosphere when they die
• deforestation releases this carbon back into the atmosphere

Question 4

The atmosphere

Answer 4

• carbon is held in the atmosphere in the form for carbon dioxide
• in recent decades, the amount of CO2 has increased due to emissions from power stations, vehicles and deforestation. This has led to the enhanced greenhouse effect and climate change

Question 5

Permafrost (cryosphere)

Answer 5

• organic matter frozen in the soil in tundra regions cannot decompose, saving prevents the release of CO2 and methane into the atmosphere / water / soil
• increased meeting of the permafrost. due to climate change is leading to a transfer of CO2 and methane into the atmosphere

Question 6

The oceans (biosphere)

Answer 6

• dissolved carbon is stored in surface ocean waters
• living organisms including plankton and shelled organisms extract carbon from the water and use it to form radio shells and videos
• when organisms die, the sink to the ocean floor where carbon is stored as ocean sediments. They also decay, releasing CO2 to deep ocean waters. The sinking of the carbon is called the carbon pump and is a slow process.

Question 7

Carbon in the lithosphere is distributed between the following stores:

Answer 7

• marine sediments and sedimentary rock
• soil organic matter
• fossil fuel deposits of coal, oil and gas
• peat

Question 8

In the lithosphere, organic deposits of carbon include…

Answer 8

Fossil fuels

Carbonate based sedimentary deposits like limestone

Question 9

In the lithosphere, organic forms of carbon include…

Answer 9

Litter, organic matter and humic substances found in soils

Question 10

The oceanic stores can be divided into three sections:

Answer 10

• the surface layer (euphoric zone) where sunlight penetrates so that photosynthesis can take place.
• the intermediate (twilight zone) and the deep layer of water
• living organic matter and dissolved organic matter

Question 11

It is estimated that the sedimentary layer at the bottom of the sea could store up to 100 million GtC. What contributes to this?

Answer 11

When organisms die, their dead cells and shells sink to deep water. Decay releases CO2 into this deep water.

Some material sinks right to the bottom, where it forms layers of carbon rich sediments, and over millions of years, chemical and physical processes turns these sediments into rocks.

This part of the carbon cycle can lock up carbon for millions of years.

Question 12

The main stores of carbon in the terrestrial cycle include:

Answer 12

• living vegetation
• plant litter
• soil humus
• peat
• animals

Question 13

Outline living vegetation as one of the main stores of carbon in the terrestrial biosphere.

Answer 13

At the global level, 19% of the carbon in the Earth’s biosphere is stored in plants.
Much of this carbon is stored directly in the tissues of the plants, but is also stored as below ground biomass (found as the roots system).
The 2 largest forest reservoirs of carbon are the vast expanses in Russia and the Amazon basin.

Question 14

Outline plant litter as one of the main stores of carbon in the terrestrial biosphere.

Answer 14

Plant litter is the fresh, decomposed and easily recognisable plant debris. This can be in the form of leaves, cones, needles, twigs. The type of litter is directly affected by the type of ecosystem.

Leaf tissues account for 70% of litter in forests, but woody litter tends to increase with forest age.

In grasslands, there is very little above ground perennial tissue so the annual fall of litter is low.

Question 15

Outline soil humus as one of the main stores of carbon in the terrestrial biosphere.

Answer 15

Soil humus originates from litter decomposition. It is the thick brown or black substance that remains after most of the organic litter has decomposed. It gets dispersed throughout the soil by soil organisms such as earthworms.

(This doesn’t answer the question but is p much all that’s in the book).

Question 16

Outline peat as a store of carbon in the terrestrial biosphere.

Answer 16

Pest is an accumulation of partially decayed vegetation or organic matter than is unique to peatlands.

Pear forms in wetland conditions where permanent water saturation obstructs flows of oxygen from the atmosphere into the ground - creating low anaerobic conditions that slow down the rates of plant litter decomposition.

Pests store 250GtC worldwide.

Question 17

Outline animals as a store of carbon in the terrestrial biosphere.

Answer 17

Animals play a small role in the store of carbon. However they are important in the generation of movement of carbon through the carbon cycle.

Question 18

When have carbon levels been at their lowest concentrations in the atmosphere?

Answer 18

Over the last 200 million years during the Quaternary glaciation.

Question 19

When have the carbon levels been at their greatest in the atmosphere?

Answer 19

Around 500 million years ago in the Cambrian period.

Question 20

The measurements from the Mauna Loa Observatory (MOO) in Hawaii show that since the Industrial Revolution, the global mean concentration of CO2 has…

Answer 20

Increased - largely attributed to anthropogenic sources, particularly the burning of fossil fuels and deforestation.