Question

for each box you will need to sketch the feedback loop from the information provided. identify each loop as positive or negative

1. as carbon dioxide levels in the atmosphere rise:

• temperature of earth rises
• the rate of photosynthesis in plants increases
• more carbon dioxide is therefore removed from the atmosphere by plants, reducing the greenhouse effect and reducing global temperatures

1. as earth warms:

• ice cover melts, exposing soil or water
• albedo (reflectivity of sunlight) decreases
• more energy is absorbed by earths surface
• global temperature rises
• more ice melts

1. as earth warms, upper layers of permafrost melt, producing waterlogged soil above frozen ground

• methane gas is released in anoxic environment
• greenhouse effect is enhanced
• earth warms, melting more permafrost

Explanation:

1. For the first scenario: The initial rise in atmospheric CO₂ causes warming, but increased photosynthesis removes CO₂, reducing warming and counteracting the original change. This is a negative feedback loop, as it stabilizes the system.
2. For the second scenario: Warming melts ice, which lowers albedo, leading to more heat absorption, further warming, and more ice melt. This amplifies the original warming, so it is a positive feedback loop.
3. For the third scenario: Warming melts permafrost, releasing methane which enhances the greenhouse effect, causing more warming and more permafrost melt. This amplifies the original warming, so it is a positive feedback loop.

Answer:

1. Negative feedback loop
2. Positive feedback loop
3. Positive feedback loop