Active measures for reducing the global climatic impacts of escalating CO2 concentrations

The buildup of CO₂ by fossil-fuel burning and associated climatic changes have become the subject of intensive investigations. Although the time scale on which significant climatic changes (e.g. mean temperature changes of several degrees, appreciable changes in global and regional rainfalls and winds, etc.) are expected to occur is long, it has been noted that the magnitude of the energy system is so vast that modifications in the primary resource mix should preferably be initiated within a decade or sooner. The notion that the most economical energy source will be replaced globally in response to longterm climate model predictions is probably false. Before policy matters of this type can be discussed reasonably, careful assessments must be made of alternative global measures that do not require curtailments of fossil-fuel applications. This study on active measures for reducing climate changes caused by escalating CO₂ concentrations deals with potentially important areas of research. We find: (a) reductions in the solar input to the Earth by reflecting sunlight directly are prohibitively costly; (b) desired changes in Earth albedo through judicious introduction of small particles can probably be accomplished at acceptable cost through the use of modified combustors on high-flying aircraft.