The carbon cycle

Question 1

Anthropogenic carbon?

Answer 1

Human activity

Question 2

Carbon sink?

Answer 2

Store of carbon

Question 3

Carbon flux?

Answer 3

movement of co2

Question 4

Where is most of the world’s co2 stored?

Answer 4

Lithosphere - 99.985%

then hydrosphere - 0.0076%

Question 5

What is the Geological compenent of Carbon ( weathering-calcium etc)

Answer 5

In the atmosphere Co2 is removed from the air and dissolves into oceans forming Carbonic acid

This then is evaporated, and reaches the surface by rain

reacts with minerals at the surface, slowly dissolving them into their component ions - chemical weathering

These ions are then transported back to the ocean through rivers and streams

form calcium carbonate which is absorbed by marine life, their skeletons sink to the bottom of the ocean and form carbonic sediment which is then stored there

Question 6

photosynthesis explain how it relates to c02

Answer 6

Carbon essential for plant growth

uptaken by plants in order for them to grow

plants act as stores of carbon, taking in more carbon and then turning it to oxygen

marine plants like phytoplankton algae absorb co2

Question 7

respiration

Answer 7

Animals absorb oxygen and produce carbon dioxide in order to achieve life function such as respiration

counter to photosynthesis

removes oxygen from the atmosphere at replaces it

Question 8

Decomposition

Answer 8

Decomposers break down material from plants and animals and release CO2 into the atmosphere

also releases into soil, air and water

process by which decomposes such as fungi and bacteria breakdown dead organisms into their simple components

Question 9

Ocean carbon pump (vertical mixing)

Answer 9

Co2 dissolves into ocean

negative relationship between sea temp and the amount of carbon that can be dissolved

Vertical mixing - warm water in oceans surface current carried from tropics to polar regions

here, water cools and becomes denser and sinks below the surface and toward the seabed.

cold water returns to the surface, warms up and loses c02 to atmosphere (evap)

Carbon pump - constant replenishment of surface water, allows oceans to take in more carbon.

Question 10

Biological pump

Answer 10

When marine organisms die, sink to bottom of the ocean, forms layers of carbon rich sediment

eventually becomes locked away in rock

Question 11

Combustion

Answer 11

organic material burnt in the presence of oxygen, to give the products of carbon dioxide

Question 12

Oceans (acidification) and stats

Answer 12

cover 70% of the earth’s surface

stores 2bn tonnes of carbon annually

35% of carbon diffuses into oceans

ocean acidification - dissolving co2 lowers the pH of the ocean becoming more acidic and less alkaline, carbonate reacts with other ions to form bicarbonate, eaten by plankton and other species, used for creation of shells.

Ocean sequestration - carbon diffuses into the ocean due to the difference in pressure.

Question 13

Farming practices (give stats on animal respiration)

Answer 13

When soil is ploughed, soil layers invert, air mixes in
dramatically increases microbial action
rapid breakdown of organic matter - releases carbon dioxide

and the carbon produced through farming equipment such as tractors

If the land is for arable agricultural - animals - high amounts of respiration producing c02

Asia responsible for 44% of agricultural related greenhouse gas

8.5% of total greenhouse gas emisiions

Question 14

How much carbon do livestock produce (%)

Answer 14

Livestock and their byproducts account for at least 32,000 million tons of carbon dioxide (CO2) per year, or 51% of all worldwide greenhouse gas emissions.

Question 15

Deforestation (amazon) and comment on water cycle/pasture land/ peatbogs

Answer 15

since the 1970s, 600,000km2 of amazon has been deforested

40% of rainforest gone by 2050
rondonia most deforestation place
80% of deforestation for pasture land

trees act as carbon sinks, removing them not only releases carbon but also stops them from absorbing future amounts of carbon

lack of trees, less photosynthesis,

forests store 100x more carbon then pasture land

also causes unbalance in the water cycle - less transpiration and evaporation which will mean less plant growth - less photosynthesis

If the forests dry out it could result in the drainage of peatbog’s which then exposes undecayed organisms releasing carbon dioxide

pasture land - respiration

Question 16

How much carbon do peatbogs store in the Amazon and how much land do they cover?

Answer 16

3% of rainforest

up to 8m thick

it stores almost 50% of its carbon stock, which equates to about three billion tonnes.

Question 17

How many tonnes of co2 released due to deforestation?

Answer 17

1.5 billion tons

Question 18

Fossil fuels and urban growth (stat%)

Answer 18

Demand for fossil fuels has risen, primarily oil and coal

fuels are burnt and they release carbon dioxide

the extraction process - mining etc also releases carbon

the consumption also increases carbon dioxide - e.g fossil fuels used to power factories, power plants, traffic, transport etc

annually, 5.5 billion tonnes of Co2 released by burning carbon dioxide

Question 19

forest fires

Answer 19

Forests - carbon sink - form of deforestation

fire - combustion, itself releases co2

occasionally fires will pose threat to permafrost, e.g siberia

Question 20

positive feedback loop - increase in temp (carbon)

Answer 20

global temp increases as more fossil fuels are burnt

temp increase

permafrost thaws (melts) releasing more c02

temp increases once more