The Carbon Cycle- W + C

Question 1

What are the transfers in the Carbon Cycle?

Answer 1

Photosynthesis, Respiration, Combustion, Decomposition, Diffusion, Erosion, Carbon Sequestration.

Question 2

Talk about photosynthesis.

Answer 2

Photosynthesis is where living organisms convert carbon dioxide and water into oxygen and glucose using light occurring in the chlorophyll in plants.

During the day, plants photosynthesise and absorb significantly more C02 than respiration emits, however photosynthesis cant occur during night.

Question 3

What is Respiration?

Answer 3

When plants and animals convert oxygen and glucose into energy producing the waste product of water and CO2.

Question 4

Define combustion.

Answer 4

When fossil fuels and organic matter are burnt, they emit carbon dioxide that was previously locked inside them.

Question 5

What is decomposition?

Answer 5

When living organisms die, they are broken down by decomposers which respire, returning carbon dioxide back into the environment. Some is also returned to the soil.

Question 6

What is diffusion?

Answer 6

The oceans can absorb carbon dioxide. This has increased ocean acidity by 30% since pre-industrial times. The ocean is the biggest carbon store however with carbon levels rising, the ocean is becoming more acidic which can harm aquatic life via coral bleaching.

Question 7

Talk about Weathering and Erosion.

Answer 7

Rocks are eroded or broken down by carbonation weathering, which occurs carbon dioxide mixes with rainwater to make carbonic acid which aids erosion.

Question 8

What is carbon sequestation?

Answer 8

The transfer of carbon from the atmosphere to other stores.

Question 9

Talk about Carbon Capture and Storage.

Answer 9

Carbon Dioxide is is captured and transported via a pipeline to underground or ocean stores. Once in ocean it will sink and remain there for many years until entering the geological cycle

Iceland holds the biggest carbon capture plant which obtains around 4,000 tones a year, However we produce 31 BILLION TONNES EVERY YEAR

Question 10

Talk about wetland restoration.

Answer 10

Rehabilitation of degraded wetland so that soils, vegetation and habitat are a close approximation of the origional natural condition. Wetland restoration provides habitats and controls erosion and flooding. Restoring mangroves, salt marshes and seagrasses reduces greenhouse gas emissions and enhances biodiversity. By protecting 6-8 million hectares of wetland allowing natural regrowth sequesting about 1gigaton of C02 by 2050.

Question 11

Talk about The Great Green Wall

Answer 11

The Great Green Wall is the initiative to increase the amount of arable land in the Sahel region including Djibouti and Sudan. The countries have joined together to combat land degration which poses serious threats including food security and desertification (effects 500 million). They do this by planting trees, 50,000 acres planted in Senegal.

Question 12

How does carbon get into the oceans?

Answer 12

Burial and compaction- Corals and other shelled sea creatures take C02 from the water and convert it into calcium carbonate to form shells. When they die they accumulate on the sea beds. Some dissolve releasing C02 and some compact into limestone.
Oceanic Carbon Pumps- Carbon is transferred around via ocean mixing which transfers atmospheric carbon dioxide to the deep sea and affects the transport of heat so has a crucial role in global climate. Warm water is carried from the tropics to polar regions. As the water cools, C02 sinks to the ocean floor and when water returns to surface and warms it loses C02.

Question 13

Whats the difference between a sink and a store?

Answer 13

Sink- Takes in more than releases
Store- emits more than it stores

Question 14

What are the main stores of carbon?

Answer 14

Marine Sediments/ Sedimentary Rocks
Oceans
Fossil Fuel Deposits
Soil Organic Matter
Atmosphere
Terrestrial Plants

Question 15

Talk about sedimentary rocks.

Answer 15

LITHOSPHERE- 66,000 → 100,000 million billion metric tonnes of carbon are held. The rock cycle and continental drift may recycle the rock overtime but this takes thousands of years.

Question 16

Talk about Oceans

Answer 16

HYDROSPHERE- 38,000 billion metric tonnes of carbon which is constantly bein utilised by marine organisms, lost as an output to the lithosphere or gains input from rivers and erosion

Question 17

Talk about Fossil Fuel Deposits

Answer 17

LITHOSPHERE- used to be rarely chaning over short periods of time but humans have developed tech to exploit them, however 4000 billion metric tonnes are still stored

Question 18

Talk about soil organic matter

Answer 18

LITHOSPERE- store carbon for over a hundred years but can be impacted by humans, 1500 billion tonnes

Question 19

Talk about the atmosphere.

Answer 19

Human acivity has causes levels to increase causing unpredictable change to the climate, 750 billion metric tonnes

Question 20

Talk about terrestrial plants

Answer 20

Venerable to climate change and deforestation, 560 billion metric tones

Question 21

What are the natural changes overtime?

Answer 21

wildfires
volcanic activity
natural climate change

Question 22

Talk about Wildfires

Answer 22

Transfer carbon from biosphere to atmosphere as CO2 is released through burning. They have an important role in the carbon cycle as they can encourage the growth of plants in the long-term due to the release of nutrient rich ash. There is much debate due to wether we should extinguish human activities as global warming is providing better conditions for wildfires to occur.

Question 23

Talk about volcanic activity.

Answer 23

Carbon stores within the eartg is released during volcanic eruptions mainly as gas. They contribute a relativley low proportion of CO2 to overall carbon cycleThe 1815 Mt Tambora eruption in Indonesia produced so much sulfuric dioxide gas, it blocked radiation from the sun lowering global temperatures bu 0.7 degrees. In this way, volcanos can influence the carbon cycle y reducing photosynthesis rates. over 130 million metric tonnes a year

Question 24

Talk about natural climate change

Answer 24

During the quaternary period, global clumates fluctuated considerably between glacial and inter-glacial periods which mirrors the levels of carbon dioxide. They get this informtion from ice cores.

An increase in carbon dioxide levels leads to an increase in temperature due to enhanced greenhouse gas effect however this can has an opposite effect as more permafrost melts, more plants can grow, more droughts, less relfection of sunlight, more wildfires: all of which can impact the levels of carbon dioxide.

The same goes for glacial periods as they can lock CO2 in ice, less phorosyntheisis and decomposition and less water flowing can reduce the amount of CO2 subsequently reducing the effectivness of the greenhouse gas effect.

Question 25

Talk about human impacts.

Answer 25

According to the IPPC, 90% of human made C02 emmissions comes from the combustion of fossil fuels and 10% from land use changes. Half of both is absorbed by the oceans and vegetation the other half absorbed into the atmoshphere

Fossil Fuel use- Combustion transfers CO2 to the atmosphere from a long-term carbon sink

Land use:
- Deforestation- used to clear for farming and housing.
- Farming Practices- Pastoral farming releases C02 and animals respore and produce methane, Ploughing can also increase CO2 stored in soil and machinery as fuel. Monoculture farming lowers biodiversity. Agriculture emits more CO2 than transport globally.
- Urbanisation- Urban areas account for 97% of all anthropogenic carbon dioxide emissions, contributes include transport, industry and cement making

Changes to the magnitude of carbon stores over time are called fluxes and may happen rapidly or over thousands of years. However human activity is causing an unprecedented flux in the levels:

From 1950, the amount of carbon increased by 4x