Week 6: Lead Lessons
Biological Impact of Climate Change
Anthropogenic climate change
2 main reasons:
- Increased levels of GREENHOUSE GASES added to atmosphere by human activities
- DESTRUCTION of CARBON SINKS [rainforests, oceans]
Effects
1. Changes in ATMOSPHERIC/OCEAN TEMP and SEASONS
2. Changes in RAINFALL PATTERNS
3. Changes in SPECIES DISTRIBUTION
Changes in temperature and seasons
Some areas will experience an INCREASE or DECREASE in temperature
Change in temp will affect ENZYME ACTIVITY
Respiration and photosynthesis both rely on enzymes
Temp changed too much => BOTH OF KEY PROCESS could be affected => affecting whole
organisms
Temperature co-efficient (Q10)
Means of expressing the EFFECT OF A TEMP CHANGE on RATE OF AN ENZYME-CONTROLLED
REACTION
- Most reactions Q10 = 2
- Rise of 10 degrees leads to a DOUBLING in rate of reaction
- Fall of 10 degrees leads to a HALVING in rate of reaction
Deviation from optimum temperature
Temperature at which they can achieve their maximal rate of reaction
- Increasing temp beyond this [global warming] => DENATURING ENZYMES and a fall in
reaction rate
- Rates of GROWTH, DEVELOPMENT/REPRODUCTION also affected
, Faster growing plants
Plants grow faster => rate of photosynthesis will need to increase to match this
Result in them REMOVING MORE CO2 from atmosphere
Optimum temp for some enzymes exceeded => plants will die along with other organisms
Tropics vs temperate
1. Tropics has SMALLEST RANGE OF TEMP CHANGES throughout year globally
2. Tropics has HIGHEST SPECIES RICHNESS globally
Tropics has roughly SAME NUMBER OF DAYLIGHT HOURS all year round [temperate regions
have LARGE VARIATION]
Tropics have LARGEST VARIATION IN RAINFALL between wet/dry seasons compared to
temperate
Organism adaptations
Tropics => show LEAST ADAPTATION to CHANGES in TEMP
Temperate => BETTER TOLERANCE to temp changes as they will have adaptations for a wider
range of temps
Desert => cope with LARGE FLUCTUATIONS in temp on a daily basis
SELECTION PRESSURE OF TEMO CHANGE WILL HAVE ADIFFERENT EFFECT ON EACH OF THESE
Biological Impact of Climate Change
Anthropogenic climate change
2 main reasons:
- Increased levels of GREENHOUSE GASES added to atmosphere by human activities
- DESTRUCTION of CARBON SINKS [rainforests, oceans]
Effects
1. Changes in ATMOSPHERIC/OCEAN TEMP and SEASONS
2. Changes in RAINFALL PATTERNS
3. Changes in SPECIES DISTRIBUTION
Changes in temperature and seasons
Some areas will experience an INCREASE or DECREASE in temperature
Change in temp will affect ENZYME ACTIVITY
Respiration and photosynthesis both rely on enzymes
Temp changed too much => BOTH OF KEY PROCESS could be affected => affecting whole
organisms
Temperature co-efficient (Q10)
Means of expressing the EFFECT OF A TEMP CHANGE on RATE OF AN ENZYME-CONTROLLED
REACTION
- Most reactions Q10 = 2
- Rise of 10 degrees leads to a DOUBLING in rate of reaction
- Fall of 10 degrees leads to a HALVING in rate of reaction
Deviation from optimum temperature
Temperature at which they can achieve their maximal rate of reaction
- Increasing temp beyond this [global warming] => DENATURING ENZYMES and a fall in
reaction rate
- Rates of GROWTH, DEVELOPMENT/REPRODUCTION also affected
, Faster growing plants
Plants grow faster => rate of photosynthesis will need to increase to match this
Result in them REMOVING MORE CO2 from atmosphere
Optimum temp for some enzymes exceeded => plants will die along with other organisms
Tropics vs temperate
1. Tropics has SMALLEST RANGE OF TEMP CHANGES throughout year globally
2. Tropics has HIGHEST SPECIES RICHNESS globally
Tropics has roughly SAME NUMBER OF DAYLIGHT HOURS all year round [temperate regions
have LARGE VARIATION]
Tropics have LARGEST VARIATION IN RAINFALL between wet/dry seasons compared to
temperate
Organism adaptations
Tropics => show LEAST ADAPTATION to CHANGES in TEMP
Temperate => BETTER TOLERANCE to temp changes as they will have adaptations for a wider
range of temps
Desert => cope with LARGE FLUCTUATIONS in temp on a daily basis
SELECTION PRESSURE OF TEMO CHANGE WILL HAVE ADIFFERENT EFFECT ON EACH OF THESE
