My last post argued that based on the figures Scientific American projected for a slow, partial phaseout of fossil fuels, we could do a full, fast, near-total elimination for between 170 and 240 billion dollars a year — somewhere less than a third, possibly even less than a quarter, of our military budget.

I’d like to offer some other comparisons to put those numbers into perspective: We spent $840 billion buying fossil fuels in 2004, according to page 72 of the 2006 Annual Energy Review (10 Meg PDF). So a 95% reduction in U.S. fossil fuel use will pay back a $170 billion annual investment by a nearly 5 to 1 ratio, and a $240 billion a year investment by well over a 3 to 1 ratio. Yes, the time value of money reduces this a great deal — but you still end up with a return exceeding that of the stock market during the bubble.

Another comparison: we sometimes talk about needing a commitment equal to what it took to win WWII. U.S. war spending grew from less than 2% of our national GDP just before Pearl Harbor, to around 5% immediately after, to around 37% at the peak of WWII defense spending. Yet in the scenarios under discussion, we advocate spending between 1% and 2% of the 13.3 trillion dollar U.S. GDP to fight global warming. So we are not talking about anything like a WWII-level commitment economically. And we don’t have to shoot anybody, or get shot by anybody, or drop any bombs.

It’s about green jobs, clean air, and a cure for our fossil fuel addiction. I think the politics are doable. If the public backs this strongly enough, they can walk right over any of the fat cats who try to get in the way.