Genomics:GTL

Fig. 1. Potential Role of Biotechnology in the Global Energy System. These diagrams show results of an economic analysis that considered competition among energy technologies in the 21^st Century and explored conditions under which biological energy sources could develop (Edmonds et al. 2003). Fig. 1A presents the MiniCAM B2 reference case. In this scenario, the world’s economic activity and number of inhabitants continue to grow, with the population reaching 9.4 billion by 2100. Energy technologies continue to improve; however, strategies to address global environmental challenges (such as mitigating greenhouse gas accumulations) are not a priority.

Fig. 1B shows another possible energy-consumption scenario in which a global commitment has been made to stabilize long-term atmospheric CO₂ concentration at 550 ppmv (about double the preindustrial level of 280 ppmv); the current level is around 380 ppmv.* Placing limits on CO₂ emissions provides an incentive for developing noncarbon-emitting energy technologies and reducing energy consumption through conservation and improvements in energy efficiency. Over the century, increased biofuel consumption combined with reductions in energy use would displace hundreds of exajoules of fossil-fuel energy (Fig. 1C), and by 2100 biofuels would equal roughly all fossil-fuel usage today (coal + oil + natural gas). By decreasing fossil-fuel use in the stabilization case, hundreds of gigatons of CO₂ emissions would be avoided (Fig. 1D).

*The case of 550 ppmv was chosen to illustrate the types of changes that might occur; currently, no scientific basis exists for preferring any particular CO₂ concentration.