Which of the following best describes the relationship between ice-albedo feedback and greenhouse-gas concentrations in Earth's climate system?

• A. Ice-albedo feedback amplifies warming caused by increased greenhouse-gas concentrations by reducing surface reflectivity as ice melts.
• B. Greenhouse-gas concentrations have no effect on ice-albedo feedback mechanisms.
• C. Ice-albedo feedback only occurs in tropical regions and is unrelated to greenhouse gases.
• D. Ice-albedo feedback decreases greenhouse-gas concentrations by increasing the amount of ice that forms at the poles.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the concept of ice-albedo feedback. Ice-albedo feedback is a climate process where the melting of ice reduces the Earth's surface reflectivity (albedo), causing more solar energy to be absorbed, which leads to further warming and more ice melting. This creates a positive feedback loop.
2. Step 2: Recognize the role of greenhouse gases in Earth's climate system. Greenhouse gases trap heat in the atmosphere, leading to an increase in global temperatures. This warming can trigger ice melting, which is directly related to the ice-albedo feedback mechanism.
3. Step 3: Analyze the relationship between ice-albedo feedback and greenhouse-gas concentrations. Increased greenhouse-gas concentrations amplify warming, which accelerates ice melting. As ice melts, the surface reflectivity decreases, further amplifying the warming effect caused by greenhouse gases.
4. Step 4: Evaluate the incorrect options. For example, the statement that ice-albedo feedback only occurs in tropical regions is incorrect because ice-albedo feedback is most significant in polar regions where ice and snow are abundant. Similarly, the idea that greenhouse gases have no effect on ice-albedo feedback mechanisms is incorrect because greenhouse gases drive the warming that initiates the feedback loop.
5. Step 5: Conclude that the correct description is: Ice-albedo feedback amplifies warming caused by increased greenhouse-gas concentrations by reducing surface reflectivity as ice melts. This explanation aligns with the scientific understanding of the interaction between greenhouse gases and ice-albedo feedback in Earth's climate system.