Scientific American presents "A Path to Sustainable Energy by 2030" in its November issue. In many ways, it sounds good. But let's think about the details: What would the end result look like? Would it really be sustainable? What would the costs really be? Is there any way we could afford to do what is proposed?

The authors of the article, Mark Jacobson and Mark Delucchi, propose substituting wind, water, and solar (WWS) energy for all other forms of energy by 2030, not for just the US, but for the world. The types of energy sources that would be eliminated include the following:

• Petroelum (including gasoline, diesel, propane, heating oil, etc.)
• Natural gas
• Coal
• Liquid biofuels, such as ethanol
• Wood and other biomass
• Nuclear

All that would remain would be wind, wave power, tidal energy, hydroelectric, geothermal, and solar. Because of the ambitious timeframe, the only techniques that can be used are ones that work at large scale today, or are very close to working.