1.14. Water and Carbon Linked

Question 1

Deforestation impact on water cycle

Answer 1

• Reduces amount of interception storage which saturates soils quicker and results in increased runoff.

Question 2

Deforestation impact on carbon cycle

Answer 2

• Decrease in carbon absorbed by trees so more stays in atmosphere which increases temps
• Clearance reduces size of carbon store
• If cleared forest is burned, there’s a rapid flow of carbon from biosphere to atmosphere

Question 3

How are carbon and water cycles linked in deforestation?

Answer 3

• Drought like conditions from lack of water leads to less plant growth which means less carbon is absorbed.
• Burning releases more carbon into atmosphere, making conditions even drier.

Question 4

Evidence to support link in deforestation

Answer 4

• 10% of the Amazon Rainforest has permanently disappeared over last 50 yrs
• 13 million hectares of forests are cleared for agriculture, logging or to make way for development every year.

Question 5

Urbanisation impact on water cycle

Answer 5

• Construction of new buildings and roads created impermeable surfaces preventing infiltration.
• This increases runoff which increases flood risk.

Question 6

Urbanisation impact on carbon cycle

Answer 6

• Switch from natural vegetation to urban surfaces (less photosynthesis)
• Increased energy consumption for transport, industry and domestic use
• Cement manufacture for urban dwellings

Question 7

How are carbon and water cycle linked in urbanisation?

Answer 7

• Impermeable surfaces = more surface runoff = flooding
• Removal of trees and use of concrete = co2 into atmosphere = more intense storms = more intensive floods

Question 8

Evidence to support urbanisation

Answer 8

• Carlisle on Eden floodplain always suffers with significant floods during heavy temp storms
• Urban areas grow by 1.3 million people every week and are home to more than 50% of the world population

Question 9

Farming practices impact on water cycle

Answer 9

Soil drainage is common in areas with high precipitation levels - use pipes to drain saturated soils to improve growing conditions- can also increase throughflow rates, potentially leading to increased flooding in adjacent areas that aren’t drained.

Question 10

Farming practices impacts on carbon cycle

Answer 10

• Animals release C02 and methane when they respire and digest food.
• Ploughing can release CO2 as microbial activity increases in soil layers inverted by ploughing.
• Growing rice in paddies releases a lot of methane too.
• As population increases so does food production.

Question 11

How are carbon and water linked in farming practices?

Answer 11

• Soil drainage leads to increased flood risk in adjacent fields.
• Farmer then uses the drained field in a way that increases carbon emissions
• Greater flood risk

Question 12

Evidence to support farming practices

Answer 12

• 44% of agricultural CO2 comes from Asia, 25% from Americas

Question 13

Impact of glacier and interglacial change on the water cycle

Answer 13

• Water locked up as snow and ice, size of freshwater store increased -> sea levels 100m lower than current
• During warmer periods in past (3 million yrs ago), ocean levels were 50m higher

Question 14

Impact of glacier and interglacial change on the carbon cycle

Answer 14

• Climates triggered by Milankovitch cycles
• Lower temps associated with CO2 levels and vice versa
• During cold periods:
  
  • Carbon stored as biomass would have become incorporated into permafrost = less atmospheric CO2
  • Increased chemical weathering -> more co2 transferred from atmosphere
  • Oceans are more saline during cold periods -> take in greater amounts of carbon via oceanic pump

Question 15

How are carbon and water linked in glacier and interglacial change?

Answer 15

• More water stored as ice means less carbon released from water.
• Warm periods -> sea levels rise due to ice melt
• Increases risk of permafrost melt - releases CH4 into atmosphere
• Accelerated warming

Question 16

Evidence to support glacier and interglacial change

Answer 16

• Every 100,000 yrs, Earth alternates between glacial and interglacial periods
• At peak of last ice age (18,000 yrs ago) 1/3 of Earth’s surface was covered by glaciers and ice sheets.