Question

in the arctic, wildfires have been increasing in both size and frequency. some of these fires, known as zombie fires, are unusual because they can continue to burn underground through the winter, even when snow covers the ground. these fires smolder in peat, a layer of partially decayed plant material that holds large amounts of stored carbon. when spring arrives and temperatures rise, these underground fires can reignite above the surface.
zombie fires release massive amounts of carbon dioxide and methane - both greenhouse gases - back into the atmosphere. this releases stored matter and energy that had been locked in the ground for thousands of years. as more greenhouse gases trap heat, the arctic warms faster, melting more permafrost and drying more peat. drier peat becomes easier to ignite, creating a cycle that releases even more stored energy from the earths surface into the atmosphere.
question: which statement best explains how zombie fires affect the flow of matter and energy?
they stop the movement of energy through ecosystems.
they create new carbon through burning.
they trap carbon and energy in the ground.
they release stored carbon and chemical energy into the atmosphere.

Explanation:

The text states that zombie fires release massive amounts of carbon dioxide and methane (greenhouse gases) back into the atmosphere. These gases were stored in the ground (in peat) for thousands of years. So, they release stored carbon and chemical energy (as the burning of peat releases energy) into the atmosphere.

• Option 1: The text shows they contribute to energy (heat) trapping (due to greenhouse gases), not stop energy movement.
• Option 2: Carbon is released, not created.
• Option 3: They release, not trap, carbon and energy from the ground.

Answer:

They release stored carbon and chemical energy into the atmosphere.