The article describing the potential use of pumping CO2 underground prompts me to provide an alternative, and perhaps less costly, way of sequestering carbon exhausted from industrial sources (HCN, 9/3/07). I would suggest that the energy producers pump gaseous CO2 through vast transparent vats filled with blue-green algae and nutrients. If the vats were placed on the roofs or the sides of a building facing the sun, algae would grow using the sunlight and excess CO2. The algae could be periodically (or continuously) harvested and refined as a biofuel, thus reusing the carbon expelled from the energy plant.

Although carbon sequestration could be done as described in the HCN article, perhaps at almost net zero carbon loss due to the necessity of requiring energy to pump the gas at very high pressure into essentially solid rock, I would suggest that the limited funds would be better spent on continued research into the adaptability of blue-green algae under elevated CO2 conditions.

Matthew Kaser
Castro Valley, California