Some Global Warming Models Predict That, If Permafrost in the Tundra

Multiple Choice

Some global warming models predict that, if permafrost in the tundra regions in the northern hemisphere melts, atmospheric CO2 levels will increase. Which of the following statements best explains this prediction?

A) The heat released by the melting of the ice on such a vast scale will cause atmospheric CO2 saturation levels to increase.
B) All of the tundra producers will die if the permafrost melts, and because the tundra regions are vast in the northern hemisphere the tundra plants will not take part in photosynthetic removal of atmospheric CO2.
C) CO2 tied up in the permafrost ice will be released during a thaw.
D) All of the undecayed organic material would be subject to decomposition following a thaw, which would lead to incredible increase in global cellular respiration, and add to atmospheric CO2.
E) All of the permafrost ice would become runoff, and this volume of water will cause sea levels to rise globally, flooding some of the most important photosynthetic CO2 sink regions on the planet.