AOS 1 unit 4

Question 1

Natural and human factors that affect Earths energy balance

Answer 1

• Solar variability
• Sun spots

Question 2

Solar variability

Answer 2

• Solar variability= The radiation reaching earth varies on a larger scale than that caused by seasons and location.
• ## The level of activity is visible to us in the form of sunspots- dark spots on the suns surface, usually relatively close to the suns equator.

Question 3

Sun spots

Answer 3

• Sun spots are associated flares, are a sign of changes in suns magnetic field. Becuase the suns interior contains flows of hot gas, the hsape and intensity of its magnetic fields change quite rapidly

Question 4

Volcanic eruptions:

Answer 4

• Volcanoes are common in many parts of the world. An erupting volcano shoots out a variety of gases, some of which are greenhouse gases

Question 5

Human activities:

Answer 5

• Human activites have changed gas composition of earths atmosphere. Activites that produce greenhouse gases include burning fossil fuels, which releases carbon dioxide.

Question 6

Earths energy budget:

Answer 6

Natural greenhouse effect= earths temperature is determined by the balance between energy input and output.
- Radiation from the sun
- The albedo effect= Albedo is a fraction of solar energy that is refelected from Earth back into space.
- Ocean circulation= Earths oceans play a major role in the storage and distribution of heat energy around the globe.

Question 7

Carbon sequestration in natural systems:

Answer 7

• Oceans → Carbon sequestration can dorm in oceans are 40% of earths carbon emissions are absorbed and stores in the oceans because carbon dioxide dissolves in seawater to form carbonic acid
• Forests → Are the most widely cited carbon sinks, storing much of the world carbon sink

Question 8

Climate vs weather

Answer 8

Weather→ Short term changes (hours, days)
- Climate → Long term patterns (decades, centuries)

Question 9

Natural factors influencing climate:

Answer 9

1. Solar radiation changes (sunspots)
2. Volcanic activity (aerosols)
3. Milankovitch cycles (orbital variations)

Question 10

Solar radiation changes (sunspots):

Answer 10

• Areas of intense magnetic activity on the sun
• More sunspots= slightly more solar energy reaching earth
• The level of activity is visible to us in the form of sunspots- dark spots on the suns surface, usually relatively close to the suns equator.
• Sun spots are associated flares, are a sign of changes in suns magnetic field. Because the suns interior contains flows of hot gas, the shape and intensity of its magnetic fields change quite rapidly.
• Sunspot cycles occur approx. every 11 years

Question 11

Volcanic activity (aerosols)

Answer 11

• Major volcanic eruptions eject aerosols into the stratosphere
• Aerosols reflect sunlight, cooling the earths surface temporarily
• Blocks sunlight from coming in

Question 12

Milankovitch Cycles:

Answer 12

• Earths orbit and tilt change over thousands of years
• Three types:
  
  1. Eccentricity (shape of orbit)
  2. Axal tilt (angle of earths axis)
  3. Precession (Wobble of earths axis)
• Affect the amount of solar energy earth receives

Question 13

-Earths orbit and tilt change over thousands of years- Three types:

Answer 13

1. Eccentricity (shape of orbit)
   
   2. Axal tilt (angle of earths axis)
   3. Precession (Wobble of earths axis)
      
      • Affect the amount of solar energy earth receives

Question 14

Why does the greenhouse effect matter?

Answer 14

• Without it, average global temperature = approx -18C
• With it, approx +15 degrees c
• Makes earth habitable - supports liquid water, ecosystems, life

Question 15

Key greenhouse gasses:

Answer 15

• Carbon dioxide (CO2) - burning fossil fuels, deforestation
• Methane (CH4)- agriculture (cattle), landfills
• Nitrous oxide (N2O)- fertilisers
• Water vapour (H20)- amplifies effect, but not caused directly by humans

Question 16

Human induced (anthropogenic) Drivers of climate change

Answer 16

• Burning fossil fuels → CO2 (carbon dioxide)
• Agriculture → CH4 (Methane) Example: cows farts, N2o (nitrous oxide) Example: fertilisers
• Deforestation→ loss of carbon sinks, Example: cutting down trees (deforestation)
• Industrial processes→ refrigerants, cement production

Question 17

Evidence of human impact;

Answer 17

• Dramatic increase post-industrial revolution (-1750)
• Strong correlation with fossil fuel use
• Data from Mauna Loa and ice cores

Question 18

Systems thinking application:

Answer 18

• Agriculture, affects on climate change
• link to each sphere

Question 19

Evidence of past climate: Proxy data

Answer 19

Proxy data: indirect evidence used to reconstruct past climate

• Acts as a ‘substitute’ for direct measurements (like temperature)

Question 20

Ice cores:

Answer 20

• Drilled down tubes into the ice
• Take back to lab
• Study what is trapped inside of the ice
• Drilled from ice sheets
• Contain air bubbles: preserved atmospheric gases (CO2, CH4)
• Layer thickness and isotope ratios→ temperature estimates

Question 21

Tree rings:

Answer 21

• Contains age of the tree
• Periods of growth
• When did the tree grow?
• precipitation or rainfall
• Each ring= one year of growth
• Thickness affected by climate (temperature, rainfall)
• Used for past 1,000 years

Question 22

Other proxy records:

Answer 22

• Sediment cores: pollen, plankton species, mineral layers
• Corals: growth bands show sea temperature and water chemistry
• Speleothems (cave formations): Contain oxygen isotopes, trace elements

Question 23

Strengths of proxy data:

Answer 23

• Extend climate change records beyond human measurements
• Allow comparison of different time periods
• Multiple proxies can validate each other

Question 24

Limitations of proxy data

Answer 24

• Indirect: require interpretation and assumptions
• Regional bias: some proxies are location specific
• Gaps in records or dating uncertainty

Question 25

Historical data: not deep time (a few hundred years ago)

Answer 25

- Ship logs (sea surface, temp, wind) - Diaries and journals (frost, rainfall, crop yield) - Weather station records (since mid-1800s) - Glacier photos and maps

Question 26

Limitations of historical data

Answer 26

- Inconsistent methods - Regional gaps in data - Observer bias

Question 27

Modern climate measurements:

Answer 27

- Thermometers and rain gauges (standardised, calibrated) - Satellite remote sensing (temp, cloud cover, albedo, sea level) - Ocean boys and Argo floats (ocean temp, salinity, currents) - Atmospheric monitoring stations (e.g Mauna loa for CO2)

Question 28

Strengths of modern climate measurments

Answer 28

- Satellite= global coverage - Modern tools= high accuracy - Long-term records= context for change

Question 29

Limitations of modern climate measurements

Answer 29

- Historical= patchy, inconsistent - Satellites= only recent decades - Calibration + interpretation required

Question 30

What is a climate model?

Answer 30

- Computer based simulations that use mathematical equations - Predict how Earths systems will respond to different inputs - Rely on historical and current data - Examples: IPCC models, GCM’s, (general circulation models)

Question 31

Inputs and variables: - Key model components

Answer 31

- Greenhouse gas emissions - Solar radiation - Aeroslos - Cloud cover - Ocean currents and temperatures - Land use and surface reflectivity (Albedo)

Question 32

Photosynthesis equation:

Answer 32

WORD: Water + carbon dioxide → (sunlight) → glucose + oxygen CHEMICAL EQUATION; 6H20 + 6CO2→ ( cunlight) → C6H12O6 + 6O2

Question 33

Feedback mechanisms/feedback loops:

Answer 33

- Climate feedbacks are processes that either amplify or weaken changes in the climate system. They’re important in climate models because they influence how fast and how much the planet warms

Question 34

Negative feedback:

Answer 34

- Higher C02 levels can increase photosynthesis - Plants grow faster and absorb more C02 from the air - This removes some C02, slowing warming slightly

Question 35

Taking action: Climate change mitigation strategies

Answer 35

- Mitigation→ reducing or preventing greenhouse gas emissions - Aims to tackle the cause of climate change - Different from adaptation (coping with effects)

Question 36

Types of mitigation stratergies:

Answer 36

- Energy→ Example: renewable energy - Transport→ Electric vehicles - Agriculture→ Methane capture - Foresty→ Reforestation - Industry→ Carbon capture and storage (ccs) - Economy→ Carbon pricing

Question 37

Evaluating effectivness→ factors to consider:

Answer 37

- Cost and scalability - Emissions reduction potential - Political and public support - Timreframe for results

Question 38

Evaluating effectivness:

Answer 38

- Not all mitigation stratergies are equally effective - Stratergies differ in cost, scale, speed or implementation and political/public acceptance - Use evidence- based comparisions to decide which stratergies are best for a given scenario

Question 39

Types of adaptation stratergies:

Answer 39

- Infastructure→ flood levees, seawall - Agriculture drought resistance crops - Ecosystem based → wetland restoration - Health→ early wanring systems - Planning→ relocation plans

Question 40

Evaluating adaption stratergies→ Consider:

Answer 40

- Cost and resources required - Local relevance and cultural fit - Salability and sustainability - Effectivness in reducing climate risk