Unit 5: Human impact on Environment

Question 1

What natural processes can cause climate change?

Answer 1

• Glaciations
• Solar activity
• Volcanoes
• Greenhouse effect

Question 2

Define albedo.

Answer 2

Ability of a surface to reflect light.

Question 3

Explain the Greenhouse effect.

Answer 3

Occurs when gases in Earth’s atmosphere trap the Sun’s heat. This process makes Earth much warmer than it would be without an atmosphere.

• Solar radiation is absorbed by earth and re-emitted to greenhouse gas molecules that re-emit down on earth = warming effect on earth
• Greenhouse gases include carbon dioxide, methane, and nitrous oxides
• Increased by human activity

Question 4

What human processes can cause climate change?

Answer 4

• release of GHG
• modification to land
• deforestation
• mining
• intensive agriculture
• water usage
• industries

Question 5

What are the main conclusions from the IPPC 2021 report?

Answer 5

1. Human influence has warmed the atmosphere
2. Scale of recent changes is unprecedented
3. Human-induced climate change already affecting weather and climate extremes
4. Estimate of equilibrium at 3°C

Question 6

What are the main and worst gases that contribute to climate change?

Answer 6

1. Methane (CH4): permafrost that thawes, and cows (agriculture)
2. Carbon dioxide (CO2): fossil fuels, land use, industries

Question 7

Why is climate change enhanced in winter?

Answer 7

All the vegetation in the northern hemisphere (most of the vegetation is in the norther hemisphere) is frozen, so it is not photosynthesizing, less CO2 absorbed = more CO2 in atmosphere.

Question 8

What are the main predictions from the IPPC 2021 report?

Answer 8

1. T° will continue to increase
2. Larger changes in climate: permafrost will melt more = ↑ CH4 emitted
3. ↑ intensity and variability in global water cycle
4. Ocean will become less effective at slowing CO2 accumulation
5. Changed due to GHG are irreversible for many centuries.

Question 9

Where do global warming happen the most?

Answer 9

• Land areas over oceans

- Artic and antartica (poles) over tropics

Question 10

What happens to the pH of oceans?

Answer 10

-ocean acidification, mostly due to CO2 dissolving in water, major impact on aquatic ecosystems.