Lecture 10: Climate Change

Question 1

Loss of Arctic Sea Ice

Answer 1

• Decrease in Albedo (the proportion of light/radiation reflected by a surface) with melting sea ice creates a positive feedback.
• Sea levels rise
• Changing ocean currents

Question 2

Ocean Acidification

Answer 2

ongoing decrease in the pH of Earth’s oceans, caused by the uptake of CO2 from the atmostpher

Question 3

Positive Feedback

Answer 3

a process that occurs in feedback loop in which the effects of a small disturbance on a system include an increase in the magnitude of the perturbation.

Question 4

Ocean Currents Slowing

Answer 4

changing ocean currents equals changing weather and potentially stronger weather systems.

Question 5

Effects on Biodiversity

Answer 5

1. Changing geographical distributions
2. Challenging physiological thresholds
3. Changing phenologies and biotic interactions

Question 6

Changing Geographical Distributions

Answer 6

latitudinal expansions/shifts are common: species expand North(or South) as climate becomes more suitable.

• Pathogens and parasites of humans interact
• High alt species vulnerable (nowhere to go to escape temp increases)
• Loss of habitat with sea level rise
• Range shifts may be natural, but habitat loss and fragmentation shifts more difficult.

Question 7

Challenging Physiological Thesholds

Answer 7

many sensitive species have limited tolerance for changes in temp, water availability, and chemistry.
-Coral bleaching

Question 8

Biotic Interactions

Answer 8

changes in timing of life histories

• Phenology: study of the timing of life cycle events.
• Timing of events may be based on day length or temp.
• Trophic Mismatch/Decoupling

Question 9

Trophic Mismatch/Decoupling

Answer 9

between a consumer and its food resource.

• Warbler migration timing is based on photoperiod cues, has not changed
• Eastern Spruce Budworm emergence in spring is based on temp cues, and has shifted to be earlier
• Warblers arrive at stopover too late to make use of peak caterpillar abundance.