Question
Today we also learned about feedback loops, these are loops that either build upon themselves, or loops that self correct. These loops can have drastic impacts on the systems of the Earth. Give an example of a positive feedback loop and explain how it fits the definition of a positive feedback loop.
Answers
Answered by
GPT-4o mini
A classic example of a positive feedback loop is the melting of Arctic sea ice as a consequence of global warming.
### Explanation of the Feedback Loop:
1. **Initial Cause**: As global temperatures rise due to increased greenhouse gas emissions, the Arctic region experiences significant warming.
2. **Melting of Ice**: The higher temperatures lead to the melting of sea ice, which normally reflects sunlight back into space (this property is known as high albedo).
3. **Reduced Albedo Effect**: When the sea ice melts, it exposes the darker ocean water beneath, which absorbs more sunlight instead of reflecting it. This leads to an increase in sea surface temperatures.
4. **Further Melting**: The warmer ocean water contributes to further melting of sea ice.
5. **Cycle Reinforcement**: As more ice melts, even more sunlight is absorbed, leading to even higher temperatures and more ice loss. This cycle can continue to intensify as the initial warming prompts further ice melt.
### Why It Fits the Definition of a Positive Feedback Loop:
- **Reinforcement**: The process amplifies itself, meaning each step leads to a further increase in temperature and subsequent ice melt.
- **System Change**: It fundamentally alters the balance of the system, leading to a more open ocean surface, which exacerbates warming and continues the cycle.
- **Long-term Impact**: This loop not only impacts the Arctic climate but also has global implications, as changes in Arctic ice can affect ocean currents, weather patterns, and global climate.
Overall, this exemplifies a positive feedback loop because the initial change (warming and ice melt) leads to effects that further increase that change, creating a cycle that can have drastic effects on Earth's systems.
### Explanation of the Feedback Loop:
1. **Initial Cause**: As global temperatures rise due to increased greenhouse gas emissions, the Arctic region experiences significant warming.
2. **Melting of Ice**: The higher temperatures lead to the melting of sea ice, which normally reflects sunlight back into space (this property is known as high albedo).
3. **Reduced Albedo Effect**: When the sea ice melts, it exposes the darker ocean water beneath, which absorbs more sunlight instead of reflecting it. This leads to an increase in sea surface temperatures.
4. **Further Melting**: The warmer ocean water contributes to further melting of sea ice.
5. **Cycle Reinforcement**: As more ice melts, even more sunlight is absorbed, leading to even higher temperatures and more ice loss. This cycle can continue to intensify as the initial warming prompts further ice melt.
### Why It Fits the Definition of a Positive Feedback Loop:
- **Reinforcement**: The process amplifies itself, meaning each step leads to a further increase in temperature and subsequent ice melt.
- **System Change**: It fundamentally alters the balance of the system, leading to a more open ocean surface, which exacerbates warming and continues the cycle.
- **Long-term Impact**: This loop not only impacts the Arctic climate but also has global implications, as changes in Arctic ice can affect ocean currents, weather patterns, and global climate.
Overall, this exemplifies a positive feedback loop because the initial change (warming and ice melt) leads to effects that further increase that change, creating a cycle that can have drastic effects on Earth's systems.