If you don't know that rehabbing the homes and other buildings we already have is going to be one of the most important initiatives of the next 20 years, it's OK. That puts you well in the mainstream.

But that's going to change. Buildings use almost half the energy in America, and there are 110 million homes alone. Even if every new building in America over that time were to be zero net energy, we will have continued to squander energy and affect the climate adversely if we don't redo what we already have.

A big question most people ask, when I talk about this, is what the payback period will be — how long before the lesser amount I'm paying for my energy will compensate for the money I had to lay out to achieve the reductions. Though I can relate to wanting to know that, I still say it is the wrong question.

First of all, what's the payoff on a utility bill? N-e-v-e-r! You just keep paying, with the almost certainty that rates will be higher next year than they are this year. You may not know the "when," but you know it's going to happen.

Secondly, though, of course, household costs are not theoretical — we have a budget at our house, too — there is more at stake than only money. Tightening up our building stock is going to help save life as we know it. No, really, it is like that.

So how do we get there sooner than soon? How 'bout a revolving multibillion dollar loan fund for building owners that has no interest or payback for, say, the first three years? That way, the larger "we" start getting the planet-saving benefits sooner, and the funds can be paid back with the energy savings that will certainly result.

Such a program will also function as an economic stimulus, giving the building industries an unending source of work and giving them cause to train and hire lots of people to get the work done. This touches on Van Jones's inspirational vision of tieing the greening of America to the economic rebirth of lower-income people. (Locally, Gary Kaplan and JFY Networks are working to implement a similar vision.)

(I saw a blog comment recently from a solar installer who said, "who needs training programs for this stuff? It's not rocket science! If we have the work, we can train on the job." Well, yes, that's partially true. But how many untrained, less-educated, inner-city people are going to get those jobs? I say, let's do both — first, underwrite the work because we have a stake in its getting done, and meanwhile, train the disadvantaged so they get a big share of the growth.)

It used to be that proposing a multibillion dollar program was nuts, 'cause where were we going to get that kind of money, but with talk of a trillion-dollar deficit, this seems easy. We "spend" the money, but unlike the bailout money that goes into the banks to cover past mistakes, this money all comes back — actually is paid back to the federal treasury.

We get the energy savings, the national security gains, the economic benefits, and the money is all paid back. Who's got a beef with that?

Let's get started.