This Pew Trust Study is interesting and probably merits getting a serious academic involved in counting these "green jobs". I respect that these guys actually state a definition (based on industry categories) of what is a green job and look at medium term growth trends (from the mid-1990s until now) by state. The green jobs total counts do look small to me. California (a state with 35 million people)has 125,000 green jobs and 6.5 billion dollars worth of venture capital invested? (see page 8).
The key issue here is the potential for this sector of the economy to accelerate. If Waxman/Markey don't sign a serious bill or if AB32 in California fizzles, will the "green job" sector fizzle? We appear to be approaching a key public sector/private sector synergy here. We need carbon pricing to gain some momentum. In the absence of carbon pricing or carbon cap & Trade, we need some "Peak Oil" and price spikes for exhaustible fossil fuels to push companies to invest in green R&D.