With a growth rate making "green jobs" one the few bright spots in the national employment picture in recent years, efforts spent to define and count these jobs reveals the sector still has some growing pains.
A recent report by the Brookings Institution and research group Battelle counted 2.7 million jobs in the United States' "clean economy," paying an average salary of $44,000 — a premium of nearly $6,000 over the average salary of all U.S. jobs.
Mark Muro, senior policy analyst at Brookings' metropolitan policy program and a co-author of the report, says the working definition "green jobs" was "any job engaged in the production of goods and services with an environmental benefit."
This includes everything from wind turbine plant workers, to organic farmers, to subway conductors.
But this vague definition doesn't sit well with others trying to capture the "green job" sector's value.
Ron Pernick, co-founder and managing director of cleantech research firm Clean Edge, says the Brookings report is a "good first effort" but that some metropolitan regions' green job impact goes undercounted because of the rapid growth in renewable energy.
He points to his home base of Portland, Ore., as an example. Though Brookings has concluded there are fewer than 100 solar-related jobs in the region, one firm, SolarWorld, has over 1,000 employees.
"Oregon should be a top-five solar state," he says, yet it languishes much further down the rankings.
"This is inevitable given how fast things are moving [in renewables], but also confirms the findings of our report — that cleantech jobs are growing very fast from a small base," counters Brookings' Jonathan Rothwell, also a co-author of the report.
"Folks [in Oregon] think we undercounted, and we agree that a few newer firms were missed, and we plan on updating the database in a few months to capture them," he says, but adds, "our estimates are larger than those produced by any other comparable source, including state labor market surveys done in Oregon" by that state's labor department.
Muro admits their broad definition didn't necessarily make the job of counting easier.
But he says that traditional job definitions — whether from the U.S. Bureau of Labor Statistics and private firms like Dun and Bradstreet — haven't caught up to some quickly evolving sub-sectors of "green jobs," such as renewable energy.
"Not only do 'green' or 'clean' activities and jobs related to environmental aims pervade all sectors of the U.S. economy, they also remain tricky to define and isolate-and count," he says.
Whatever the counting process, some interesting trends emerge from the Brookings report.
The relatively lower education levels of "green collar" workers in the report bodes well for this hard-hit portion of the unemployed; 47 percent of green jobs requiring a high school degree or less-compared to the overall average of around 37 percent .
According to the report, another 22 percent of green jobs require a Bachelor's degree or higher, compared to around 33 percent overall.
The current unemployment rate among those with high school diplomas or less is 14.3 percent.
Other findings show that despite the West Coast's reputation of being cutting edge in the green sector, the south has the largest number of clean-economy jobs overall; seven of the 21 states in that region have at least 50,000 such jobs in the sector.
Less surprising is the concentration of green jobs in urban centers; three-quarters of all new ones can be found in the nation's cities.
The report also found that green jobs were manufacturing-intensive, with 26 percent of them coming in manufacturing and export, compared to a 9 percent national average.
But while the renewable energy segment grew at a rapid 8.3 percent annual rate, the bulk of "green jobs" Brookings counted were not in these high-growth areas.
Most jobs were counted in mature segments like mass transit, or in areas like housing improvements.
Ironically, this latter segment weighed upon the wider sector's growth over the 2003-2010 timeframe of the report; the housing sector reduced green-job growth to 3.4 percent from a national average of 4.2 percent in the same period.
Subsidy and Controversy
One of the biggest knocks against these jobs is the perception that they survive on government subsidy, moving workers away from other segments of the economy.
"There is no money shed from which the government can finance all the green subsidies," David Kreutzer of the conservative Heritage Foundation noted this past spring. "These resources are extracted from other parts of the economy. They do not, and cannot, come from outside the economy."
Clean Edge's Pernick says that continued job growth in the sector at this stage relies ultimately on new technologies, and as with biotech or the Internet, this often requires government incentives of some kind.
Even if the U.S. cuts subsidies for areas like wind and solar power, "the Chinese are spending hundreds of billions" of dollars" and Germany and Japan both are looking to move beyond nuclear to cleaner forms of energy.
The next wave of technological advance in renewable energy will need to come from somewhere, he adds.
"This is really about the U.S.' technological competitiveness," he says. "The U.S. [government] has got to take a stand. If it doesn't we will lose out on the technologies — and jobs — of the future."
Brookings' Muro says that while his report didn't address the impact of growth in the clean economy on other sectors of the economy, he says: "We don't believe that job growth in the clean economy will come at the expense of jobs in any other sector. Rather, we see the clean economy as an important potential source of new jobs and new growth at a time the country needs both."