The study's call for prompt and aggressive energy research and development distinguishes it from the Bush administration's Energy Plan, which focuses on domestic oil exploration, and the recent United Nations Intergovernmental Panel on Climate Change "Mitigation" report, which indicates that existing technologies can stabilize human-induced adverse climate change.
The research team, which also included Tyler Volk, associate professor of biology at New York University, focused on the following alternative energy sources: terrestrial solar, wind, and solar power satellites, biomass, nuclear fission, nuclear fusion, fission-fusion hybrids and fossil fuels from which carbon has been removed or "sequestered". Scientists evaluated the different technologies for their capability to supply mass amounts of carbon-emission-free energy required to satisfy current world energy consumption (estimated at 10 terawatts of power), their ability to meet future energy consumption (estimated at 30 terawatts of power) and their potential for large-scale commercialization. The team also explored non-primary power technologies that could contribute to climate stability and slow down global warming, such as conservation, efficiency improvements, hydrogen production, storage and transport, superconducting global electric grids and geoengineering.
CO2 emissions from fossil fuels trigger global warming by enhancing the atmosphere's "greenhouse effect", which traps energy that would otherwise radiate from earth back into space. Due to population growth and industrialization, atmospheric CO2 has increased from 275 parts per million to 370 parts per million over the last century, and is projected to pass 550 ppm this century. Given that 85% of the world's energy is derived from carbon dioxide-emitting fossil fuel, climate models and data indicate that the earth's temperature could climb 1.5 to 4.5 degrees Celsius (3 to 8 degrees Fahrenheit) over the next century, comparable in magnitude but opposite in sign to global cooling of the last Ice Age.
"What our research clearly shows is that scientific innovation can only reverse this trend if we adopt an aggressive, global strategy for developing alternative fuel sources that can produce up to three times the amount of power we use today," said Dr. Hoffert. "Currently, these technologies simply don't exist - either operationally or as pilot projects."
Dr. Hoffert's team's analysis clearly delineates the advantages and limitations of each alternative power source. For example, while replacing combustion engines with fuel cell engines appears promising in cutting down the CO2 emissions vehicles, the study demonstrates that the current process of producing the hydrogen required to power fuel cells actually creates more CO2 emissions than the combustion engines would create. Photovoltaic or "solar" energy, which requires only the sun as fuel, would require surface arrays of roughly the size of the entire Sahara desert to meet the world's current power needs and there is limited infrastructure for transmitting this power across distances. Even solar space power, which the study points out is more efficient in harnessing power because it evades the earth's spinning, cloudy atmosphere, could only meet the world's existing energy needs with 660 energy units, each of which having a surface array of roughly the size of Manhattan.
"The disparity between what is needed and what can be done without pain becomes more acute as the global economy grows," Hoffert added. "Therefore, what is needed now is political will, targeted research and development and international cooperation."
The research paper was published in Science under the title "Advanced Technology Paths to Global Climate Stability: Energy for a Greenhouse Planet." In addition to Dr. Hoffert and Dr. Volk, the paper's authors include Ken Caldeira and L. John Perkins of Lawrence Livermore National Laboratory, Gregory Benford of the University of California, David R. Criswell of the University of Houston, Christopher Green and H. Douglas Lightfoot of McGill University, Howard Herzog of the Massachusetts Institute of Technology, Atul K. Jain and Michael E. Schlesinger of the University of Illinois at Urbana-Champaign, Haroon Kheshgi of ExxonMobil Research and Engineering Company, Klaus S. Lackner and Michael E. Mauel of Columbia University, John S. Lewis of the University of Arizona, Wallace Manheimer of the Naval Research Laboratory, John C. Mankins of NASA and Tom M.L. Wigley of the National Center for Atmospheric Research.
The project was partially funded by the Department of Energy's Office of Biological and Environmental Research and the Office of Fusion Energy Sciences.
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