Chemistry of the Atmosphere

Question 1

Proportion of gases in the Earth’s atmosphere:

Answer 1

21% oxygen. 78% Nitrogen.

Question 2

What is oxygen?

Answer 2

Oxygen is a reactant in respiration and travels through the blood in human bodies to provide for cells.

Question 3

What is nitrogen?

Answer 3

Nitrogen is a key component of proteins which is essential for growth. The producers at the base of the protein absorb soluble nitrates from the soil.

Question 4

What are carbon dioxide and water vapour?

Answer 4

Greenhouse gases.

Question 5

What is the greenhouse effect.

Answer 5

Greenhouse gases absorb and then re-radiate heat energy that is reflected off the earth’s surface. If the effect is too strong it can cause global warming.

Question 6

The earth’s atmosphere contains small quantities of gases such as…

Answer 6

Noble gases, carbon dioxide and water vapour.

Question 7

Once dissolved in the oceans, some of the carbon dioxide reacted with seawater to produce…

Answer 7

…carbonate precipitates that were deposited as sediment.

Question 8

For the first billion years of the Earth’s existence:

Answer 8

Highly active volcanoes populated the surface.

Question 9

What is needed for photosynthesis to take place?

Answer 9

Carbon Dioxide.
Light Energy.
Water.

Question 10

Which 3 main factors caused the decline of CO2 in the atmosphere?

Answer 10

Evolution of marine animals.
Formation of the oceans.
Evolution of photosynthetic organisms.

Question 11

What are algae?

Answer 11

Algae were the first photosynthetic organisms to evolve. Oxygen slowly built up in the atmosphere until photosynthesising plants were eventually able to evolve.

Question 12

A photosynthesising plants began to evolve…

Answer 12

…the rate of oxygen accumulation increased rapidly, until a threshold concentration was met that made it possible for humans to evolve.

Question 13

Animals were only able to evolve when…

Answer 13

…oxygen had become abundant in the atmosphere.

Question 14

Which gases were released by volcanic eruptions in the earth’s early atmosphere?

Answer 14

Carbon Dioxide. 
Nitrogen. 
Ammonia. 
Methane. 
Water Vapour.

Question 15

Describe the greenhouse effect process:

Answer 15

Earth absorbs short wavelength radiation.
Greenhouse gases absorb long wavelength radiation.
The Sun emits short wavelength radiation.

Question 16

Which human activities cause atmospheric concentrations of greenhouse gases to increase?

Answer 16

Burning fossil fuels.
Landfill sites (decomposition produces methane).
Deforestation.
Agriculture (farm animals release methane during digestion).

Question 17

Greenhouse gases can’t absorb the frequencies of radiation that arrive from the Sun, but they can absorb some…

Answer 17

…reflected radiation before re-radiating it in all directions, including back towards Earth.

Question 18

How could global climate change affect extreme meteorological events?

Answer 18

Increased frequency.

Increased severity.

Question 19

The current scientific consensus is that…

Answer 19

…increased greenhouse gas emissions caused by changes to human activity will lead to global climate change.

Question 20

Possible consequences of global climate change include:

Answer 20

Melting of polar ice caps.
Changes to amount and timing of precipitation.
More extreme meteorological events.
Changes to water availability.
Food shortages (leads to potential famines).

Question 21

What is the evidence that greenhouse gases are related to climate change?

Answer 21

The current scientific consensus, which is based upon peer-reviewed evidence, that is increased greenhouse gas emissions caused by changes to human activity will lead to global climate change.

Question 22

What is the misinformation about climate change?

Answer 22

The complexity of the global climate system makes it difficult to create accurate models - often biased information on inadequate models.

Question 23

The melting of polar ice caps would cause:

Answer 23

• Sea levels rise, leading to flooding and erosion of coastal regions.
• Some species to be less successful hunters (e.g the polar bear).

Question 24

What would changes in water availability effect?

Answer 24

Species distributions.

Question 25

What is a carbon footprint?

Answer 25

A carbon footprint is a measure of the total amount of greenhouse gases emitted as a result of a particular service, event or product.

Question 26

What are the barriers to reducing carbon footprints?

Answer 26

• Reluctance to lifestyle changes.
• Scientific disagreements regarding climate change.
• Conflict of interest with economic development.
• Failure to sign international agreements.

Question 27

Any governments worry that making the required changes may restrict…

Answer 27

…the economic development of their country, thus risking the health of their population.

Question 28

How can governments reduce their carbon footprints?

Answer 28

• Emission-based taxes.
• Emission caps.
• Emission licences.

Question 29

How can individuals reduce their carbon footprints?

Answer 29

• Maximise energy use efficiency.
• Minimise waste.
• Use renewable energy sources.

Question 30

Name the following methods for reducing carbon footprints:

Answer 30

Carbon capture and storage technology
Carbon neutral products
Carbon off-setting