According to this, California’s total greenhouse gas emissions rose by about 14 percent from 1990 through 2004.

OK, so that’s not exactly good news.

But it’s not the worst news in the world either, really. Over the same period, California’s population grew by about 20 percent; so, running the numbers, it looks as if per person emissions fell by about, oh, 5 percent. That is, at the same time California’s cars and homes got bigger and its economy boomed, the state managed a 5 percent reduction in per-capita GHG emissions.

And about that economy — adjusting for inflation, California’s economy (as measured by Gross State Product) grew by about 50 percent from 1990 to 2004. Again, running the numbers, that means that climate warming emissions per dollar of economic output fell by about a quarter from 1990 through 2004.

Obviously, though, what really matters is total emissions: the climate isn’t affected by per capita emissions, or per dollar emissions, but just by emissions, period.

Still, the news does suggest that, even in a policy environment with relatively low energy taxes and limited investments in conservation, per capita emissions have fallen. Now that California’s ramped up its commitment to climate change, could we see even faster reductions in per capita emissions? Time will tell.