✅C&W 3.1.1.4 - Water, Carbon and Life on Earth

Question 1

What type of feedback is sea ice melting?

Answer 1

Positive

Question 2

How do marine phytoplankton link the water and carbon cycles?

Answer 2

They store carbon as living organisms, but are part of the ocean and allow formation of clouds, and therefore precipitation as part of the water cycle

Question 3

What type of feedback is permafrost melt?

Answer 3

Positive

Question 4

How does permafrost melt link to the carbon cycle?

Answer 4

The organic matter in permafrost can contribute CO2 to the atmosphere as it melts, impacts climate change

Question 5

What is lag time in terms of climate change?

Answer 5

The delay between the change occurring in the climate and it having an effect

Question 6

What is climate change mitigation?

Answer 6

Efforts made to reduce or prevent emissions of greenhouse gases

Question 7

Agreement in Paris Climate Deal 2015

Answer 7

Aim to limit rise of global temp. to only 2°C above pre-industrial level

Question 8

Where is the degree of ocean warming greatest?

Answer 8

Near the surface

Question 9

How much as the ocean warmed by per decade since 1971?

Answer 9

0.11 degrees C

Question 10

How much has global mean sea level risen by since 1901?

Answer 10

0.19m

Question 11

Why is CO2 increase a positive feedback?

Answer 11

As CO2 warms the atmosphere, it results in higher evapotranspiration rates and wetter atmosphere, leading to further warming

Question 12

Other than CO2, what can cause the greenhouse effect?

Answer 12

Water vapour, clouds, aerosols

Question 13

Why is sea ice melt a positive feedback loop?

Answer 13

Ice reflects radiation from the sun, so less heat is absorbed
As sea ice is shrinking, less reflection and more absorption
Water warms further
Warmer waters melt ice

Question 14

How do marine phytoplankton aid cloud formation?

Answer 14

They release a chemical substance called DMS which can lead to gormation of condensation and clouds over oceans

Question 15

Why are marine phytoplankton causing a negative feedback loop?

Answer 15

As temperatures warm, phytoplankton numbers increase, clouds increase, global temperatures cool

Question 16

How does plant growth act in a negative feedback loop?

Answer 16

More CO2, more plant growth, up to limiting factor, more photosynthesis, less CO2 in atmosphere

Question 17

Are warmer waters more or less able to dissolve CO2?

Answer 17

Less

Question 18

Why are water and carbon important to all living organisms?

Answer 18

Make up matter of people, plants, animals etc
All organisms need water to survive drinking etc
Carbon is essential for plant growth and warmth

Question 19

What is one of the key links between water and carbon cycles? - carbonic acid

Answer 19

Absorption of carbon in rain water, makes carbonic acid
Carbonic acid rainwater erodes rocks like limestone, releases carbon. Positive feedback
This rainwater also falls into ocean, carbonic acid mixes with carbonate ions to form bicarbonate. species like phytoplankton need carbonate ions to form their shells, therefore they have fewer carbonate ions available to use for their shells- making them more vulnerable

Question 20

What is one of the key links between water and carbon cycles? - tree growth

Answer 20

young trees photosynthesise more to grow, take up more CO2, but this is up to limiting factors, like water. Therefore, the afforestation of an area becomes harder and less valuable as deforested areas have less moisture in the air

Question 21

What is one of the key links between water and carbon cycles? - atmospheric gas store

Answer 21

CO2 warms air, can store more water vapour stored in warm air. Therefore more intense and sporadic rainfall

Question 22

How can changing rural land use positively affect climate change?

Answer 22

Planting trees can remove CO2 from the atmosphere, and fields not ploughed to retain carbon in the soils rather than being released as CO2

Question 23

What are the advantages of land use changes?

Answer 23

Greenhouse gas emissions reduced
Reduced labour
Reforestation increases biodiversity
Floods less likely

Question 24

How do newly grown trees absorb carbon

Answer 24

They have greater carbon uptake, due to growth (up to other limiting factors like water availability), but this doesn’t continue when they get older.

Question 25

What are the disadvantages of changing rural land use?

Answer 25

Reforestation needs to keep occurring to become carbon neutral
Not always more productive farming
Yield may be lowered with reduced use of fertilisers
May increase chance of wildfires
Reforestation not fast enough- 15 milion trees deforested/ year, 5 million afforested + can be costly

Question 27

How successful is carbon capture technology?

Answer 27

Its complications can outweigh its benefits, as CO2 concentrations in the air are still very low and so to have a meaningful impact huge quantities of air would have to be processes.

Question 28

What are the advantages of carbon capture?

Answer 28

Techniques well understood and easily operated, good health and safety
Fossil fuel burning plants can have carbon capture built in- can capture 90% of CO2 emissions produced
Potential to capture 1/2 of world’s CO2 emissions
Demand increasing- 27 facilities in 2021, 35 in 2022
Can significantly reduce emissions from plants

Question 29

What are the disadvantages of carbon capture?

Answer 29

More energy required for plants fitted with the technology, which can increase emissions indirectly
Can damage environment with leakages of CO2 underground- but no leaks yet
Expensive