Question

part 1c: describe a feedback loop involving permafrost thaw that includes at least two earth systems (spheres) from the list below.
your response may include multiple feedback loops, if that helps you talk about two systems more easily.
you can use ideas we have built as a class throughout the unit as part of your thinking.
you may annotate on the model to support your response.
atmosphere biosphere cryosphere geosphere hydrosphere

Explanation:

Permafrost is part of the cryosphere. When it thaws, it releases methane and carbon - dioxide into the atmosphere. These greenhouse gases trap heat, causing more warming. The increased warming then leads to more permafrost thaw, creating a positive feedback loop between the cryosphere and the atmosphere. Also, thawed permafrost can change the landscape (geosphere) and affect plant and animal life in the biosphere. For example, the collapse of ground due to permafrost thaw can damage habitats.

Answer:

One feedback loop is between the cryosphere (permafrost) and the atmosphere. As permafrost thaws, it releases greenhouse gases (methane and carbon - dioxide) into the atmosphere. These gases cause more warming, which in turn leads to more permafrost thaw. Another possible aspect is the impact on the biosphere. Thawed permafrost can change habitats, affecting plant and animal life.