Permafrost query

[Charise]

I am working on a new unit for my 8th grade science class and am somewhat perplexed about the permafrost carbon cycle. What I understand is - as the permafrost melts carbon is released in the form of carbon dioxide due primarily to the decomposition of the organic material in the soil by bacteria. Is this the primary action or does the soil simply release the stored carbon? Or have I completely misunderstood?

[David]

I think a greater danger may be a massive release of methane resulting from a thawing of the tundra. Methane is a more potent greenhouse gas than carbon dioxide.

[Mosca]

As I understand this, the melting of the permafrost is also a feedback loop.

As more carbon dioxide and methane gas are released, more permafrost melts. And as more permafrost melts, more co2 and methane are released. The increase increases! This becomes exponential.

And it has already started.

This is one of the most frightening aspects of global climate change.

[Charise]

I was actually more confused about the exact process of release of both methane and carbon dioxide. Are both primarily released due to decomposition of the soil via bacteria?
From what I have read methane is more potent but persists for less time in our atmosphere than carbon dioxide. The more research I do, the more I realize there is probably quite a bit my students are unaware of. Hopefully we can generate some great discussions.

[Charise]

I found an excellent website (finally) on the subject:
http://nsidc.org/cryosphere/frozengro...