California has a requirement that all new buildings be zero carbon by 2020; every electron a building uses must come from power generated onsite. Obama plans the same requirement nationwide by 2030.

So you would think that to meet their new neighborhood certification, on-site renewable energy would be a LEED requirement, not just an option. But it won’t be. What’s worse, it will be worth a measly 3 points out of the total 110 possible points to get LEED certification. But you can change that.

Every year America throws away 250,000 homes.

Bulldozers are knocking down almost 700 houses every day and trucks are carting the demolition debris for burial in landfills all across the country. It's estimated that 1.2 billion board feet of usable lumber ends up in the garbage, not to mention salvageable hardware, fixtures, wiring, piping, doors and windows.

But a new appreciation of the value of this waste stream is leading to the growth of a nascent industry: deconstruction. In a worsening economy and in the effort to create green jobs for a low-carbon future, deconstruction could prove to be a boom industry -- if it wasn't so cheap to throw things away -- creating jobs, recycling valuable materials and recovering and reusing the energy embedded in these existing construction materials.

The New York Times Magazine followed around a deconstruction crew involved in the painstaking, labor-intensive work led by Brad Guy, a "journeyman architectural academic" who is supervising the deconstruction of two homes in Cleveland, one of the cities hardest hit by the subprime mortgage crisis. The city of Cleveland is expecting to spend $9 million in the next year demolishing 1,100 of its 8,000 vacant homes. It's a $9 million expenditure that is largely headed headed straight for the dump.

What if that money could be put to more productive use? It's a question Cleveland is exploring by helping to fund Guy's experiment in deconstruction -- to determine whether the cost of the labor required to deconstruct some of these homes would be offset by the value of the material the labor recovers. The short answer appears to be yes.

As Wall Street and the American economy continue to crumble around us, it is time - now more than ever - to begin building the next American economy - the low carbon, clean energy economy.

Former President Bill Clinton believes that creating the low carbon clean energy economy presents the greatest economic opportunity for the United States since it mobilized for World War II. He has it exactly right. Here are three examples.

Building efficiency.

Take New York City, for example, where we have almost one million buildings. If we decided to reduce carbon emissions 30 percent in those buildings and systematically pursued that goal for 20 years, we would save tens of
billions of dollars a year and create tens of thousands of jobs. It would be a whole new economy for New York to build on as it reels from the losses on Wall Street. Mayor Mike Bloomberg is going to need a strategy like this to rescue New York.

Every city in America could do the same thing. Enormous savings and a massive economic engine would result. Wholesale, retail, shipping, manufacturing and retrofitting businesses would all grow steadily to meet the need. Sales of insulation, caulking, windows, doors, furnaces, boilers, air conditioners and dozens of other products would skyrocket.

And we'd need tens of thousands of plumbers, electricians, carpenters, and contractors to make it happen.

The American Council for an Energy-Efficient Economy (ACEEE) has just handed out its annual energy efficiency rankings for the US states. Here are the top 10:

10. New Jersey
9. Wisconsin
7. Minnesota (tie)
7. Massachusetts (tie)
6. Washington
5. New York
4. Vermont
3. Connecticut
2. Oregon
1. California

Stats: California earned 40.5 total points, out of 50. Wyoming was dead last with zero. Idaho (number 13) earned "most improved." Wisconsin scored in the top ten (a first). Rhode Island was the most energy-efficient as a percentage of its total electrical sales -- achieving a savings of 1.23 percent.

More to the point: The US states, combined, spent two to three times more than the federal government did on energy efficiency -- the most common-sense and available solution to energy and climate change.

The clean energy economy is already working in unforeseen ways. The latest beneficiary? A Denver-based company called Prologis, the world's largest owner and manager of industrial warehouses and distribution facilities.

What does Prologis have more of than anyone else -- to offer the clean energy economy?

Here's a hint: the company has more than $40 billion of real estate assets under management representing more than 500 million square feet of space in North America, Europe and Asia.

The answer is: rooftops. Acres and acres of sun-washed rooftops. And Prologis is starting to cash in.