"...faith in technologies, markets, and correcting feedback mechanisms is less than satisfying for a situation such as the one you are studying at this year's Ewing Symposium... Few people doubt that the world has entered an energy transition away from dependence on fossil fuels and toward some mix of renewable resources that will not pose problems of CO2 accumulation. ...I'm generally upbeat about the chances of coming through this most adventurous of all human experiments with the ecosystem.... Beyond our normal twenty-year outlook period, we recently attempted a forecast of the CO2 [carbon dioxide] build-up. We assumed different growth rates at different times, but with an average growth rate in fossil fuel use of about one percent per year starting today, our estimate is that the doubling of atmospheric CO2 levels might occur sometime late in the 21st century. That includes the impact of a synfuels industry. Assuming the greenhouse effect occurs, rising CO2 concentrations may begin to induce climactic changes around the middle of the 21st century.... Clearly, there is vast opportunity for conflict. For example, it is more than a little disconcerting the few maps showing the likely effects of global warming seem to reveal the two superpowers losing much of the rainfall, with the rest of the world seemingly benefitting."