This post is by Jackie Roberts, director of sustainable technologies at Environmental Defense Fund.

Shifting to a low-carbon economy means creating renewable energy and energy efficiency technologies. This will take a lot of work, but in a good sense. We'll see increased investment, new businesses, and new products to manufacture — the creation of many new jobs.

The ball won't start rolling in earnest until the U.S. passes cap-and-trade legislation, but movement has already started. For example, check out this map we created of green businesses and their suppliers in Ohio:

To get a sense of the larger impact, we've mapped the green economy in other states, as well. More on this in a future post.

The project started with a simple question:

How can we concretely describe the economic opportunity of a low-carbon economy?

To find the answer, we scoured Web sites, databases, and news stories, and called companies across the country with questions. The process was labor intensive and sometimes tedious, but eye-opening. We found that new jobs from a growing green economy are a reality today, but the potential is even more exciting.

Some of the businesses we identified were obviously part of the green economy — for example, companies that perform energy efficiency audits. But the cascade effect can be surprising. We also identified businesses that manufacture nuts, bolts and bearings for wind turbines, and businesses that make piping and generators for industrial waste heat recovery systems. These suppliers may not even think of themselves as part of the green economy.

As our list got long, we looked for a way to succinctly convey the data and discovered Google maps. We created interactive states maps with the names and locations of each company. Renewable energy businesses and their suppliers are marked in green, and energy efficiency businesses and suppliers are marked in blue. The maps vividly convey the economic potential.

We're adding companies to the maps all the time — most recently through our own original research on the supply chains of green technologies. It's exciting research that's only just beginning. Stay tuned.