In 1977, the physicist Freeman Dyson proposed the burial of biomass, as a scalable, economical solution to the Carbon Dioxide problem. Today we know that the harvested vegetation should be salted and buried in an engineered dry biolandfill. Plant biomass can be preserved for thousands of years by burial in a dry environment with sufficiently low thermodynamic “Water Activity”, which is the relative humidity in equilibrium with the biomass. Helpful to maintaining a dry environment within the engineered dry biolandfill is the recognition that salt preserves biomass, which has been known since Babylonian times. A “Water Activity”<60% will not support life, suppressing anaerobic organisms, thus preserving the biomass for millenia. Current agriculture costs, and biolandfill costs indicate US$60/tonne of sequestered CO2 which corresponds to ~US$0.53 per gallon of gasoline. The technology is scalable owing to the large area of land available for cellulosic crops, without disturbing food production. If scaled to the level of a major crop, prior years CO2 can be extracted from the atmosphere, and in addition, a significant fraction of annual world CO2 emissions can also be sequestered.
Prof. Yablonovitch (Electrical Engineering and Computer Sciences Dept., University of California, Berkeley, CA, 94720)