Which statement about permafrost feedback in a warming climate is most accurate?

• A. Warming reduces permafrost; no effect on methane.
• B. Permafrost thaw releases carbon quickly, but methane release has no climate effect.
• C. Methane release occurs slowly and negligible.
• D. Methane release from thawing permafrost can amplify warming, creating a positive feedback.

Answer: (D)

Thawing permafrost can speed up warming because it releases stored organic carbon as greenhouse gases, especially methane, whose heat-trapping power is very strong on short timescales. When permafrost thaws, microbes break down the newly exposed organic material and emit carbon dioxide and methane. Methane is a potent greenhouse gas, so these releases can boost the atmosphere’s temperature, which then causes more permafrost to thaw. That creates a self-reinforcing, positive feedback loop: warming leads to more methane release, which leads to more warming.

So the statement that methane release from thawing permafrost can amplify warming, creating a positive feedback, is the best answer. The other ideas miss that methane does affect climate, that permafrost thaw can release carbon rapidly, and that methane release is not negligible in its climatic impact.