The Water and Carbon Cycle

Question 1

What is the carbon cycle

Answer 1

Exchange of carbon between all of Earth’s components:
- atmosphere
- oceans and rivers
- rocks and sediments
- living things

Question 2

Basis of carbon cycle

Answer 2

2 processes
- photosynthesis
- respiration

Question 3

Photosynthesis is:

Answer 3

• energy from sun and CO2 create oxygen and sugars
• sugars / carbohydrates stored in biomass, used to grow

Question 4

Respiration:

Answer 4

• breaks down carbohydrates to use them
• CO2 released into atmosphere

Question 5

Carbon cycle involves

Answer 5

• flux and flow of carbon between different Earth systems

Question 6

Carbon sink

Answer 6

• object or process absorbs and stores carbon
• e.g. healthy plant

Question 7

Carbon source

Answer 7

• object or process releasing carbon faster than absorbs
  e.g. eaten plant (utilised for energy) burnt or decompose

Question 8

Human impact - fossil fuels - on carbon cycle

Answer 8

Large
- fossil fuels - coal, oil, gas - contain large amounts carbon
- formed over millions of years decompose plants and animals
- burn fossil fuels release CO2 faster than natural processes

Question 9

Human impact - deforestation - on carbon cycle

Answer 9

deforestation

Question 10

What happens to CO2

Answer 10

• plants absorb some additional CO2
• most remains in atmosphere

Question 11

Human impact - urbanisation - water and carbon cycle

Answer 11

• leads to modified size water and carbon stores
• impacts rates of flow / flux between stores

Question 12

Human impact - urbanisation - water cycle

Answer 12

impact most apparent at local / regional scale
- most evident in rivers / aquifers
- rising demand for water creates shortages

Question 13

CO2 absorption

Answer 13

• More than half of CO2 from fossil fuel combustion absorbed by phytoplankton
• Significantly more than rainforest

Question 14

Threat to phytoplankton carbon store

Answer 14

• Acidification of oceans

Question 15

Threat to soil carbon store

Answer 15

degraded by:
- erosion
- deforestation
- agricultural mismanagement

Question 16

Major carbon stores

Answer 16

• phytoplankton
• soil
• wetlands

Question 17

Threat to wetlands carbon store

Answer 17

drained for:
- cultivation
- urban development
depleted
- dry out, become oxidised

Question 18

Global management protect carbon cycle

Answer 18

• wetland restoration
• afforestation
• agricultural practises change
• international agreements
• carbon trading and agreements
• CCS

Question 19

Types of wetland:

Answer 19

• saltmarsh
• peat land
• flood plain
• mangrove swamp

Question 20

Conditions of wetlands

Answer 20

• anaerobic conditions
• restoring can turn carbon source back to carbon sink

Question 21

Negative feedback loop definition

Answer 21

Functioning loop that feeds back and remains the same
- Current paradigm altered by event
- Series of processes / fluxes situations rebalanced back to paradigm
- e.g. sea / evaporation / precipitation / run-off / river / sea

Question 22

Dynamic equilibrium

Answer 22

Water and carbon cycle maintain this with constant:
- input
- throughput
- variable stores
- outputs

Question 23

Dynamic equilibrium changes:

Answer 23

Short term:
- experience change and imbalance
Long term:
- negative feedback loops maintain balance

Question 24

Water cycle - impacts of natural changes over time
Seasonal

Answer 24

seasonal changes:
- storm events increase channel flow and surface run-off
- drier seasons lead to less river discharge and run-off
- mountainous regions ice melt-flow water increase cf and ro

Question 25

Water cycle - impacts of natural changes over time Ecosystem

Answer 25

plant successions - change in dominant vegetation type - reduced vegetation (e.g. after plant death) leads to reduced: - water absorption - transpiration - precipitation

Question 26

Human impact - urbanisation - water cycle land use

Answer 26

- Natural to urbanised landscape create impermeable surfaces - Run off increased, infiltration decreased - Increase flooding when rivers recieve run-off too quickly

Question 27

Positive feedback loop definition

Answer 27

Event / change happens but paradigm is not re-reached - processes occur as a result, outcome will differ to origin every time it circles - e.g. permafrost time bomb, each time melts / freezes permafrost gets smaller - tipping point, climate change will be irreversible

Question 28

How human activity changes carbon stores - temperatures

Answer 28

- higher global temperatures - accelerate carbon transfer from biosphere and soil to atmosphere

Question 29

How human activitty changes carbon stores - water table

Answer 29

- water table decreases - less rain captured on leaves - leads to less clouds, less precipitation - less groundwater absorption