Natural Leaking
Even if the carbon dioxide could be transported and installed in the underground seams safely, there is then the matter of the storage itself. It is naïve, perhaps even a bit arrogant and ridiculous, to believe that we can honestly store a gas underground without any leakage. Even a very subtle slow leak which is bound to occur with any storage method, will still negate any supposed benefits that the idea of storing CO2 proposed in the first place. However, this leakage would not only present the standard problems of CO2 emissions in relation to global warming, but the deadly gas would also threaten humans and other animal life and plant life in the areas where the leaks occurred. Gas will naturally leak from any surface, that is simply how it works, so storage of the CO2 is merely shifting the problem from the plant creating the gas to the storage area.
Mammoth Mountain:
Mammoth Mountain, in California, has taught us this lesson. Although plants in the normal “breath” cycle absorb carbon dioxide and release oxygen back into the air, they can still be affected by the gas when it leaks into the soil from underground, which literally begins to suffocate the roots of trees and other plants such as in the case of Mammoth Mountain. The leaks in Mammoth Mountain were also responsible for lethal build ups of carbon dioxide in poorly ventilated buildings. Since carbon dioxide is an invisible and odorless gas it can often become quite deadly before anyone is even aware that there was a problem with the leak in the first place.
Seismic Activity:
You then have the problem of worrying about seismic activity and geological processes. Something we can neither control, prevent, or accurately predict. Large seismic disturbances, or even smaller scaled activity could potentially release large quantities of deadly CO2 gas, poisoning water supplies, endangering the lives of people in near by communities, and wreaking havoc on the environment.