Can "green" fuels replace oil? Short answer: hell, no.

CNet has the bad news.

4.2 billion ...That's how many rooftops you'd have to cover with solar panels to displace a cubic mile of oil (CMO), a measure of energy consumption, according to Ripudaman Malhotra, who oversees research on fossil fuels at SRI International... [in other words,] we'd need to equip 250,000 roofs a day with solar panels for the next 50 years to have enough photovoltaic infrastructure to provide the world with a CMO's worth of solar-generated electricity for a year. We're nowhere close to that pace.

Many of these stats and a far lengthier discussion of the issue will be found in a book coming from Oxford University Press by Crane, Malhotra, and Ed Kinderman called A Cubic Meter of Oil... And judging by some of the stats Malhotra gave me, the book will alarm policy makers, environmentalists, and pretty much anyone else interested in weaning ourselves from fossil fuels...

One of the more compelling aspects of Malhotra's research is how it highlights the amount of energy, particularly in the form of fossil fuels, that the world consumes. Oil provided about one-third of worldwide energy (1.06 CMO) in 2006 followed by coal (0.81) and natural gas (0.61). Together, the three fossil fuels accounted for 2.48 CMOs of the 3 CMOs consumed that year.

The figures drop quickly after that. The fourth largest source of energy is biomass, mostly in the form of burning wood. Biomass, however, only provide 0.19 CMOs, while hydroelectric and nuclear provided, respectively, 0.17 and .015 CMOs...

The minuscule size of renewables, unfortunately, also means progress will come slowly. Some more comparisons: A large hydroelectric dam can generate about 18 gigawatts of power a year. To get an annual CMO from new hydroelectric dams, you'd need to build the equivalent of 200 Three Gorges Dams. There aren't that many available rivers in the world left to dam up. Solar thermal? 7,700 plants, or 150 a year for 50 years, required for an annual CMO. One plant went up last year, and it was the first in over 15 years. In his calculations, Malhotra takes into account the fact that solar, wind, hydroelectric, and even nuclear plants don't operate at optimal conditions 24-7; in other words, he has baked in real-world assumptions.

If consumers worldwide could replace 1 billion incandescent bulbs with compact fluorescents, it would save only 0.01 CMOs in a year...

"What is truly humbling is that we aren't going to make any impact on CO2 emission levels for the next 20 to 30 years," Malhotra said. Much of the growth for energy demand will come from emerging markets...

Saying that we may need oil for the next few decades is like telling someone in the path of a hurricane that they may experience moisture.

Update: Charlie Foxtrot: "Starvation = Greener Planet."