carbon cycle

Question 1

define carbon sink

Answer 1

any store which takes IN more carbon than it emits eg. Amazon rainforest

Question 2

define carbon source

Answer 2

any store which EMITS more carbon that it stores

Question 3

what is the main store of carbon

Answer 3

sedimentary rocks at 100 million gigatonnes

Question 4

how much have co2 levels risen since the industrial revolution (1750)

Answer 4

40% increase

Question 5

how does deforestation affect the carbon cycle

Answer 5

-less trees to remove co2 > more atmospheric co2 > enhances GH effect > global warming
-less leaf litter > humus not formed > soil cant support much growth > limits amount of carbon stored

Question 6

negative feedback in carbon cycle starting w global temps increase

Answer 6

> more plant growth > increases co2 uptake > reduces atmospheric co2, reducing global temps

Question 7

positive feedback in carbon cycle starting w increasing temperatures because of climate change >

Answer 7

permafrost melts > releases GH gases > enhances GH effect > increases temps

Question 8

name 4 processes which transfer co2

Answer 8

photosynthesis, respiration, diffusion, decomposition

Question 9

how does the natural process of wildfires affect the carbon cycle?

Answer 9

loss of vegetation decreases rates of photosynthesis, less carbon removed from atmosphere
lots of carbon is transferred from biomass to atmosphere

Question 10

how do farming practises affect the carbon cycle

Answer 10

ploughing releases co2 stored in soil
rice paddies release lots of methane

Question 11

define the carbon budget

Answer 11

difference between inputs + outputs of carbon

Question 12

name 4 inputs of carbon into the atmosphere

Answer 12

volcanic eruptions, burning fossil fuels, respiration and decomposition

Question 13

name 2 outputs of carbon from the atmosphere

Answer 13

photosynthesis and carbon sequestration

Question 14

define photosynthesis

Answer 14

living organisms convert carbon dioxide from the atmosphere with water into - glucose and oxygen

Question 15

define respiration

Answer 15

respiration occurs when plants and animals ​convert oxygen and glucose into energy = produces ​waste products of water + CO2​

Question 16

what is combustion

Answer 16

when any organic material is burned in the presence of oxygen to give off co2

Question 17

what is decomposition

Answer 17

decomposers like worms/bacteria breakdown organic material
this releases carbon

Question 18

what is climatic climax

Answer 18

the final stage of the sere where environmental equilibrium is achieved

Question 19

marine sediments and sedimentary rock store the most carbon, how much is this?

Answer 19

100 million gigatonnes

Question 20

what is the second biggest carbon store?

Answer 20

oceans - 38,000 GT of carbon

Question 21

is volcanic activity and fossil fuel combustion part of the slow or fast carbon cycle?

Answer 21

volcanic activity - SLOW
fossil fuel combustion -slow

Question 22

what is water abstraction

Answer 22

when water is removed from stores for human use
increases in dry seasons

Question 23

what is the global effect of water abstraction

Answer 23

leads to a decline in global long-term water stores

Question 24

explain diffusion in relation to the carbon cycle

Answer 24

oceans absorb atmospheric carbon
has increased ocean acidity by 30% since pre-industrial levels

Question 25

explain weathering in relation to the carbon cycle

Answer 25

atmopsheric co2 mixes with rainwater creating weak carbon acid
erodes limestone - called carbonation

Question 26

explain ocean carbon sequestration

Answer 26

marine shell organisms die, fragments of shell sequestered at bottom of ocean

Question 27

explain sedidement carbon sequestration

Answer 27

organic matter/vegetation decays, is compacted

Question 28

what does carbon sequestered by oceans/sediment form

Answer 28

over millions of years = fossil fuel deposits