My wife and I had the pleasure of leaving Las Vegas last night. We were in the city for the weekend to visit friends who moved there from Portland earlier this year. We love our friends, but our next get-together is going to have to be in Portland or some neutral location.

This was my first trip to Vegas for something other than to attend a conference. Since my last visit almost 10 years ago, it’s fair to say my environmental consciousness has been raised. So when I looked upon the huge glimmering casinos on The Strip this time, I couldn’t help but shudder at the unsustainability of it all. And surrounding the city core are vast grids of slapped-together strip malls and subdivisions entirely dependent upon the automobile for their existence.

Yes, we saw the occasional Prius and solar panel array. And we visited the outstanding Spring Preserve, a 180-acre venue within city limits meant to “provide a vision for a sustainable future.” I also understand many casino hotels are doing more to conserve energy and the city is trying to encourage more dense “non-gaming” residential development. But the sheer enormity of the casino industry in Las Vegas makes the thought of sustainability almost absurd. I can’t imagine how much energy is consumed and CO2 emitted each hour as the casinos suck in electrons for their humongous neon signs, ubiquitous slot machines and the computing farms that keep all the gaming operations running. And with each new casino hotel complex, the ante gets raised in size and sizzle.

The greening of Las Vegas remains strictly of the monetary variety. SustainLane ranked Las Vegas the 27th most sustainable city in its 2006 ranking of the 50 largest US cities. (That seems very generous.) The organization placed Portland at the top. I was no doubt experiencing this chasm between the two cities this weekend. An environmentally green Las Vegas seems far-fetched as long as casinos dominate its economy and suburban-style development continues unabated. Still, I’m confident things can change there. And they must, if we are to stop gambling away our energy future.