I’ll soon be tackling new eco-job and career issues, but I’ve got one last piece of business related to my time at the Good Jobs, Green Jobs conference last week. I’ve recounted what happened and who was there, and explained how we might define green jobs. Now, I’ll address one final question from Grist readers: “What’s the main barrier to the growth of green jobs?”

In a word: politics. In the dim past (1970-1999), it was generally agreed that government action was needed to generate environmental protection and conservation. And we learned along the way that creative public policies, regulations, and investments aimed at air quality, water quality, conservation, and better control of toxic materials generated all sorts of economic benefits in the form of new technologies and lots and lots of “environmental” jobs.

Sometime in the last few years, the idea started to take hold that the financial advantages of “sustainability” were so obvious that “the market” alone would become the primary driver for a whole boatload of new green jobs at every level of the workforce. Certainly, logical people would see, for example, that massive investment in retrofitting buildings to be dramatically more energy efficient would produce a great return on investment in just a few short years. Get out of the way and let market-based environmentalism do its thing in a more unfettered world.

Not so fast, grasshopper.

For the promise of green jobs to really take off, we need innovative government policies, incentives, investments, regulations, and direct programs aimed at fueling private-sector investment and job creation. The “green economy” won’t spring up like weeds after rain — even with the rising cost of a barrel of oil.

Demanding government action to create the right conditions for green job creation isn’t a rap on the green jobs movement. It’s a sign that it’s realistic. You think that Big Oil, Big Coal, and big Bear Stearns brokerage bailout bankers haven’t figured out that government support is absolutely essential to the health of their industries? Read David Roberts’ excellent posts from the ECO:nomics conference for your answer to that one.

That doesn’t mean that there aren’t lots of new green jobs being created all over the country in solar energy, wind power, green buildings, organics, mass transit, and related fields. And it doesn’t mean that there aren’t tens of thousands of current jobs that are being reshaped with new “green” training and certification requirements. Of course there are, and I’ll have lots of stories to tell about them as the year goes on.

It does mean, however, that the main thrust of the green jobs movement right now is political, and that’s just as it should be. Government action is still one of the primary drivers in our efforts to become more carbon-neutral, and government action comes out of big, strong coalitions of organized voters.

The green jobs folks, with their focus on an economy that deals effectively with climate change and also provides good jobs for lower-income people with “more than high school but less than a four-year degree,” are testing the validity of the sustainability idea right now in the real world.

They’re asking whether we really mean it when we say that there’s a new kind of world possible that generates economic security and ecological health and social justice at the same time. Or whether we’ll jettison the social justice of the sustainability equation along the way, just as we have so many times in the past.

It’s no wonder that they get a little annoyed by people who keep asking for evidence of a massive green jobs payoff right now. Work with us, they say, to get local, state, and federal government leaders who want to innovate and invest in partnership with business, unions, universities, and activists.

That’s a necessary prerequisite to a new kind of green economy, and the lack of it is the central barrier to success.