Earth Life Support System- Pt 3

Question 1

What is an example of a negative feedback loop for the water cycle?

Answer 1

Heavy rain increases the amount of water that’s stored in aquifers, which raises the water table. This then increases the flow from springs until water returns to normal levels.

Question 2

What is an example of a negative feedback loop for the carbon cycle?

Answer 2

Burning fossil fuels increases CO2 so increases photosynthesis, which removes CO2 from the atmosphere to maintain equilibrium.

Question 3

What are the examples of how land use changes the water and carbon cycles?

Answer 3

Urbanisation
Farming
Forestry

Question 4

How does urbanisation affect the water cycle?

Answer 4

The natural surfaces are replaced by impermeable surfaces so infiltration is reduced. Therefore an increased risk of flooding as there’s more surface run-off.

Question 5

How does urbanisation affect the carbon cycle?

Answer 5

More transport means that there’s more CO2 emissions into the atmosphere so ore light is used which increases energy intake.

Question 6

How does farming affect the water cycle?

Answer 6

The use of heavy machinery can compact the soil and increase surface run-off.

Question 7

How does farming affect the carbon cycle?

Answer 7

The clearance of forests for farming reduces the carbon storage in, above and below ground biomass.

Question 8

How does forestry affect the water cycle?

Answer 8

Higher rates of rainfall interception in plantations in natural forests so increased evaporation, meaning reduced run-off and stream discharge.

Question 9

How does forestry affect the carbon cycle?

Answer 9

Changing land use from farming to forestry increases the carbon store, meaning that there’s more flux of CO2 in and out of trees.

Question 10

What is our example of surface extraction?

Answer 10

The River Kennet

Question 11

Where is the River Kennet located?

Answer 11

South England

Question 12

What is surfaceextraction?

Answer 12

Extraction of water from rivers

Question 13

What does the River Kennet supply water for?

Answer 13

Industry and agriculture.

Question 14

Where is most of the flow from the River Kennet from?

Answer 14

Groundwater

Question 15

What has been the impact of surface extraction of the River Kennet?

Answer 15

Groundwater extraction have exceeded rates of recharge which means water table has fallen.
Lower flows reduce risk of flooding and temporary areas of standing water on floodplain.

Question 16

When was there a drought from the River Kennet?

Answer 16

In 2003 and flows fell by 20%.

Question 17

What is sub-surface extraction?

Answer 17

Extraction from aquifers and artesian basins.

Question 18

What is an artesian aquifer?

Answer 18

When a borehole is used to tap groundwater so that it will flow to the surface under its own pressure.

Question 19

What is a potentiometric surface?

Answer 19

It is level to which the water from an artesian basin will rise to.

Question 20

What does a potentiometric surface depend on?

Answer 20

Whether the water will come out naturally or pumped out of theground.

Question 21

What is an a potentiometric surface determined by?

Answer 21

By the height of the water table in areas of recharge on the edges of the basin.

Question 22

What is an example of an area that sits on top of an artesian basin?

Answer 22

London

Question 23

Why was the groundwater from the artesian basin in London an important supply of water during the 19th century?

Answer 23

It was essential for meting the demand for industrial, commercial and public demand as London expanded.

Question 24

What is the risk now of the artesian basin in London?

Answer 24

The water table has recovered but there is still a potential risk of flooding.

Question 25

For the last 200 years what has been the industry driven by fossil fuels?

Answer 25

Global industrialisation and urbanisation

Question 26

What percentage of our energy consumption is fossil fuels?

Answer 26

80%

Question 27

What has the concentration of CO2 increased from 1750 to 2022?

Answer 27

From 280ppm to 421ppm

Question 28

How long has theCO2 concentration in the atmosphere been the highestfor?

Answer 28

800,000 years.

Question 29

What is anthropogenic CO2?

Answer 29

CO2 that's produced by humans

Question 30

How much do anthropogenic emissions make up of the natural flux of carbon?

Answer 30

less than 10%

Question 31

What is one possible solution to capture and store carbon?

Answer 31

Carbon capture and storage

Question 32

What is carbon capture and storage?

Answer 32

A process in which carbon dioxide from industrial sources is separated, treated and transported to a long-term storage location.

Question 33

What is a negative of carbon capture and storage?

Answer 33

It's not economically viable.

Question 34

What is the first stage of carbon capture and storage?

Answer 34

Separating CO2 from power station emissions

Question 35

What is stage of 2 of carbon capture and storage?

Answer 35

Compressing and transporting the CO2 by pipelines to where it is stored.

Question 36

What is stage 3 of carbon capture and storage?

Answer 36

It is then injected into porous rocks deep underground for permanent storage.

Question 37

How effective is carbon capture and storage?

Answer 37

It has the ability to reduce emissions by 80-90%.

Question 38

What is an example of how the carbon capture and storage project hasn't been effective ?

Answer 38

There are Pilot projects at Peterhead in NE Scotland but the increasing costs axed the project as it was too expensive.

Question 39

What is the economic factor that limit the effectiveness of carbon capture and storage?

Answer 39

It has a high setup cost (also known as a capital cost).

Question 40

How much did it cost to setup the carbon and capture storage programme in Peterhead?

Answer 40

£1 billion

Question 41

What is the geological factor that limit the effectiveness of carbon capture and storage?

Answer 41

Specific geological conditions are needed for areas to act as storage.

Question 42

What is an example of positive feedback loop in the water cycle?

Answer 42

Melting sea ice exposes the ocean and so less solar radiation is reflected. The ocean then absorbs more heat and warms up so melts more sea ice.

Question 43

What is an example of positive feedback loop in the carbon cycle?

Answer 43

Warmer temperatures increase permafrost melting, releasing methane and carbon back into the atmosphere and driving enhanced greenhouse effect.

Question 44

How are we monitoring changes to the global water and carbon cycles?

Answer 44

Satellite technology and remote sensing Use of GIS

Question 45

How many satellites are there above the Earth's surface?

Answer 45

10,000

Question 46

What is remote sensing as a way of monitoring the carbon and water cycles?

Answer 46

It gets info without touching/from a distance.

Question 47

What does GIS stand for?

Answer 47

Geographical Info Systems

Question 48

What do satellites enable us to do?

Answer 48

Monitor change so that temporal changes can be identified. Data can then be mapped by GIS which gives us a spatial context so helps to identify trends and anomalies.

Question 49

What is the mean residence time?

Answer 49

The amount of time molecules stay in the system on average.

Question 50

How do we calculate the net flux of something?

Answer 50

Input-Output

Question 51

What does diurnal mean?

Answer 51

day

Question 52

What are the diurnal changes in the water cycle?

Answer 52

Lower night temps reduces evapotranspiration. More humidity can reduce precipitation.

Question 53

What are the diurnal changes in the carbon cycle?

Answer 53

Growth during daylight hours means CO2 flows from atmosphere to vegetation, same with phytoplankton in oceans.

Question 54

What are the seasonal changes in the water cycle?

Answer 54

Evapotranspiration is the highest in the summer and lowest in winter. River levels normally lowest in summer.

Question 55

What is evapotranspiration controlled by?

Answer 55

The variations in intensity of solar radiation.

Question 56

Why are river levels normally lowest in summer?

Answer 56

due to soil exhaustion of soil moisture and much precipitation lost to evapotranspiration.

Question 57

What are the seasonal variations in the carbon cycle?

Answer 57

NPP varies monthly Summer in N hemisphere has a net global flow of CO2 from the atmosphere to biosphere.

Question 58

What are the two short term changes in the water and carbon cycles?

Answer 58

Diurnal Seasonal

Question 59

How many glacial cycles have there been in the last 400,000 years?

Answer 59

4 major

Question 60

What is the average global temperature in modern day?

Answer 60

22 degrees C

Question 61

What was the average global temperature 250 million years ago?

Answer 61

7-8 degrees higher than now at 22 degrees.

Question 62

Why has the change in global temperatures been slowing the water cycle?

Answer 62

There's more freshwater stored as snow and ice. There's reduced exchange of water between the atmosphere and oceans, biosphere and soils.

Question 63

What are the key changes during glacial periods?

Answer 63

There's a net transfer of water from oceans to storage in ice sheets and glaciers which creates the sea levels to drop. Drier climate in the tropics.

Question 64

How much does ice sheets and glaciers cover of continental ice mass when there's a glacial period?

Answer 64

1/3 of the continental ice mass

Question 65

What does it mean when there becomes a drier climate in the tropics during glacial periods?

Answer 65

The rainforests are replaced by deserts and grassland.

Question 66

What are the 2 main long-term changes in the carbon cycle?

Answer 66

There's a big decrease in CO2 in the atmosphere. The carbon store shrinks and the carbon flux slows.

Question 67

Why has there been a big decrease in CO2 in the atmosphere?

Answer 67

Suggested that CO2 finds its way into the deep oceans from the atmosphere. OR CO2 is more soluble in surface waters at lower temperatures.

Question 68

How does CO2 find itself into the oceans from the atmosphere as a long term change in the carbon cycle?

Answer 68

There are changes in the oceans circulation which means that nutrients are brought to the surface. This stimulates phytoplankton growth and fixes large amounts of CO2 which is stored in deep oceans.

Question 69

Why has the carbon store shrunk?

Answer 69

Deserts are expanding with tundra replacing temperate forests and grasslands start to replace rainforest, meaning that biosphere is decreased overall. NPP declines so less CO2 is fixed.

Question 70

Why has the NPP decreased for long term changes in the carbon cycle?

Answer 70

Due to there being less vegetation cover, fewer forests, lower temps and precipitation.

Question 71

Why has the carbon flux slowed?

Answer 71

There's less carbon exchanged with the atmosphere as much of the land surface is buried by ice and carbon is trapped under those soils.

Question 72

What has the atmospheric CO2 concentration increased from?

Answer 72

280ppm in 1750 to 393ppm in 2012.

Question 73

What does ppm stand for?

Answer 73

Parts Per Million