1.4 - Peatlands

Question 1

What are peatlands?

Answer 1

• Waterlogged landscapes
  
  • high water table
• Dead vegetation builds up in waterlogged areas
  
  • can only partially decay due to anaerobic conditions
  • means that carbon is preserved
• With time, pressure and heat peat turns into lignite -> bituminous coal -> Anthracite

Question 2

Why are peatlands important?

Answer 2

• filter heavy metals toxins + purify water
• serve as a habitat for rare wetlands species
• hold 1/3 of worlds organic soil carbon
• Holds 2x as much carbon as all of Earth’s living forests
  
  • only cover 3% of surface

Question 3

How much carbon was released from Indonesian peatlands during 2015’s wildfires?

Answer 3

• 23% of Indonesia’s total carbon emissions
  
  • more than that associated with US economic activity

Question 4

Where are peatlands found?

Answer 4

• Mostly northern hemisphere
  
  • UK uplands, Canada, Baltic nations, North Russia + North Alaska
• cover 4 million km²

Question 5

Where are the world’s largest tropical peatlands?

Answer 5

• Congo swamps
  
  • contain around 3 years worth of world’s total fossil fuel emissions

Question 6

What happens if the peat is dry?

Answer 6

• Aerobic conditions
  
  • decay occurs, carbon returns to atmosphere

Question 7

What happens if the peat is wet?

Answer 7

• Anaerobic conditions
  
  • carbon cannot decay
  • CO₂ locked away as solid dark organic matter in peatlands
  • methane released however
  • carbon within peat dissolves into rainwater that percolates through peat
  • also released when peat below water line decomposes

Question 8

What happens when the peat is waterlogged?

Answer 8

• Plant growth is interrupted
  
  • plant is in anaerobic conditions, denitrifying bacteria cannot absorb as much CO₂, thus cannot make nutrients needed for plant growth

Question 9

How do peatlands introduce variability?

Answer 9

• Unknown just how much carbon is stored in all peatlands
• Variance in the effects of draining peatlands to different extents
• Burning peatlands could trigger a positive feedback cycle
• Rate of restoration of peatlands is unknown

Question 10

How does permafrost introduce variability?

Answer 10

• Unknown how much permafrost has warmed so far
• Unknown how much methane is stored in permafrost/left to be released
• how much the fact that CH₄ is a more potent GHG when compared to CO₂ actually matters