3.2 - Ocean Acidification

Question 1

How much of total carbon emissions could be absorbed by the ocean?

Answer 1

• 30%

Question 2

How much larger than the terrestrial stores is the oceanic store?

Answer 2

• 50x

Question 3

What causes oceanic acidification?

Answer 3

• When carbon diffuses into water, creates a weak carbonic acid
  
  • this is made worse when fossil fuels are burnt releasing more carbon to be absorbed by the ocean

Question 4

How does carbonic acid cause bleaching?

Answer 4

• carbonic acid reacts with carbon ions
  
  • creates bicarbonate ions
• coral uses carbonate ions to create calcium carbonate
  
  • reduction in a amount of carbonate ions means more energy is needed to build shells
  • results in shells becoming thinner and more fragile
  • acidic water dissolves carbonate shells

Question 5

How can the affects of ocean acidification be made worse?

Answer 5

• warmer temperatures
  
  • results in algae being expelled from coral
  • reduces the ability of coral to photosynthesise
  • means shells are weaker
    
    • however, increased phytoplankton growth in warmer waters is good for coral
• destructive waves/cyclones
  
  • easily break coral

Question 6

How can ocean acidification occur naturally?

Answer 6

• there is very little photosynthesis in deep ocean
  
  • CO₂accumulates
• CO₂ is also produced near volcanic vents on seabed

Question 7

Why is coral so hard to revive?

Answer 7

• takes a decade for algae to return to coral
  
  • takes about as long for coral to be healthy again

Question 8

How is does ocean acidification contribute to a positive feedback cycle?

Answer 8

• ocean acidification results in reduced dimethyl sulfide production
  
  • produced by phytoplankton
• less sulphur compounds are present in the atmosphere
• less nuclei for condensation to form around
• less cloud cover
• less reflection of sunlight
  
  • more thermal energy absorbed by Earth
  • more warming