C13

Question 1

what are the proportions of gases in the atmosphere today?

Answer 1

• 80% nitrogen
• 20% oxygen
• small proportions of other gases, like carbon dioxide, water vapour and noble gases

Question 2

Theories suggest that the first billion years of the Earth’s existence included intense volcanic activity. This released what?

Answer 2

• carbon dioxide
• nitrogen
• a little methane
• a little ammonia
• may have also released water vapour which formed oceans
• NO oxygen

Question 3

How has the Earth’s atmosphere changed over time?

Answer 3

• As earth cooled, water vapour condensed and formed oceans
• CO2 dissolved in the oceans which formed hard precipitates (solids). Some of it was used by sea creatures to make shells, and these later formed rocks
• 2.7billion years ago, algae, and later plants, began producing O2 by photosynthesis, which also reduced CO2 levels. Animals evolved as oxygen levels rose
• Fossil fuels contain large amounts of carbon, which came from CO2 in the early atmosphere

Question 4

Name the 3 main greenhouse gases

Answer 4

• water vapour
• carbon dioxide
• methane

Question 5

Greenhouse gases like CO2 allow ___ from the sun to pass through the ____

Answer 5

• shortwave radiation (uv)
• atmosphere

Question 6

The energy of the radiation is ___ when it reaches the ____ of the earth

Answer 6

• absorbed
  -surface

Question 7

The surface of the earth now ____ the energy as ____ radiation such as infrared

Answer 7

• radiates
• long wavelength

Question 8

CO2 then ____ some of the outgoing longwave radiation, causing the atmosphere to ____

Answer 8

• absorbs
• warm up

Question 9

without the greenhouse affect, the earth would be _____

Answer 9

too cold to sustain life

Question 10

what are the effects of climate change?

Answer 10

• weather pattern changing (flooding/droughts)
• extreme weather (e.g. hurricanes)
• ice caps and glaciers melting
• sea levels rising, causing flooding
• desertification
• reduced yield of crops
• habitats changing

Question 11

Carbon dioxide

Answer 11

Cause: Complete combustion
Problem: global warming

Question 12

Carbon monoxide

Answer 12

Cause: incomplete combustion
Problem: toxic gas, colourless and odourless

Question 13

Sulfur dioxide

Answer 13

Cause: oxidation of sulfur impurities in fossil fuels
Problem: acid rain, respiratory problems

Question 14

Oxides of nitrogen

Answer 14

Cause: oxidation of nitrogen in air at high temperatures in a vehicle engine
Problem: acid rain and respiratory problems

Question 15

Carbon particulates

Answer 15

Cause: burning diesel
Problem: global dimming, health problems

Question 16

How is human activity increasing carbon dioxide levels?

Answer 16

• combustion of fossil fuels
• deforestation

Question 17

How is human activity increasing methane levels?

Answer 17

• farming cattle
• growing rice
• use of landfill

Question 18

What is carbon footprint?

Answer 18

the total amount of carbon dioxide and other greenhouse gases emitted over the full life cycle of a product, service or event

Question 19

how can you reduce carbon footprint directly?

Answer 19

• using “green” energy sources that don’t emit CO2 (i.e. solar or wind power)

Question 20

how can you reduce carbon footprint indirectly?

Answer 20

• insulating buildings so less heating is required, requiring less fossil fuels to be burnt