Biotechnology
Another focus area in GTSP Phase II is biotechnology. The achievement of market penetration of commercial biomass cannot occur with present technology. Harnessing advances in the genomic sciences could enable the development of new plants with attractive features such as the ability to be refined into a high energy density product in the field. Almost as important are continued advances in crop productivities. With these continued advances, lands currently needed for food production can be released to energy production. In that same vein, the development of rice strains with low methane emissions and low emissions of other greenhouse gases such as nitrous oxide may be made possible through biotechnology. It may also be possible to develop bioreactors that can harness the potential of microbial organisms, such as photosynthetic bacteria, to produce clean fuels such as hydrogen. These bioreactors can exploit our increasing understanding of microbial enzymes and metabolic pathways.
Advanced biotechnology, including increased agricultural productivity and new bioprocessing techniques, may provide a unique, closed loop contribution to our energy needs in the future.
Traditional plant breeding attempts to increase crop productivity by increasing photosynthetic efficiency, producing stronger, deeper root systems, and imparting increased resistance to drought, heat, and cold stress and to disease, insect, and weed damage. Genetic engineering provides new tools that may facilitate achievement of these objectives. Already genetic engineering has proven effective in creating cultivars genetically coded for protection against specific viral diseases and insects. Weeds in fields of the genetically engineered "Round-up Ready" cultivars of a number of important crops are effectively and cheaply controlled in an environmentally beneficial way. In 2001 more than 52 million hectares were planted with genetically engineered crops worldwide. The USDA estimates that more than 36 million hectares were planted in corn, soybeans, and cotton in the United States in 2002 . Recent success in mapping the genomes of japonica and indica rice indicates that an even wider variety of genetic modifications of crop plants are in the offing.
A special section in Science (296:115) on the rice genome explains, "Through selective breeding, humans have for many thousands of years promoted development of desirable traits and discouraged development of undesirable traits in the crops we rely upon. More explicit knowledge of gene function, the genetic control networks, and the cellular physiology that cause these traits allows for more refined management of these traits". Thus the use of Genetically Modified Organisms (GMOs) could profoundly affect the ways in which land resources are allocated in the future to food, feed and biomass production. Still more so if genetic engineering also improves livestock feeding efficiency, thereby reducing the area needed to support each animal.
Biotechnology may also be applied to enhanced productivity of biomass crops. In addition, a need exists for biological agents and processes that effectively breakdown raw biomass to concentrated forms that are more economically transported or even that allow for on-farm production of final products in the form of combustible solids, liquids, or gasses.
Another realm in which biotechnology may contribute to stabilization of greenhouse gas emissions is soil carbon sequestration. Participants at the St. Michaels Workshop "Carbon Sequestration in Soils: Science, Monitoring and Beyond" sponsored by DOE and other agencies. (Rosenberg and Izaurralde, 1999; 2001) indicated the need for research on biological and physical methods to stabilize carbon incorporated into soil in chemically and physically recalcitrant forms. Plants bred for greater lignin and cellulose content offer one pathway for accomplishing this. Ways must also be found to increase the binding of organic materials on mineral surfaces and in aggregates with pores too small for bacterial penetration. Genetically altered plants may contribute to these objectives. Biotechnology may also offer opportunities to stimulate microbial processes that foster long-term soil carbon sequestration.
A three-year effort is envisioned involving dedicated workshops, simulation modeling, and integrated assessment. Information on actual and potential accomplishments of biotechnology with respect to crop and biomass productivity, energy concentration, and soil carbon sequestration will be parameterized and used to drive the crop growth model i-EPIC to estimate potential impacts on the global scale. Projected impacts on crop and biomass yields and soil carbon sequestration will be incorporated in runs of the SGM model and the developing modules of the TGM.