On a family trip to Colorado this month, we made a short stop at the National Center for Atmospheric Research (NCAR) in Boulder. They run a nice lunchtime tour there, and it was interesting to hear what they're working on in the area of climate change and modeling. They bought a Connection Machine that I helped design way back in the Thinking Machines days, and I've always loved visiting there.
I couldn't resist asking one embarrassing question, though. When we were standing in front of their world-class supercomputing center talking about how it was helping analyze climate change, I had to raise my hand and ask how much CO2 that data center was responsible for? I know from our data center near Boulder that the electricity there is very "dirty" (over 2 pounds of CO2 per kWH, much higher than the national average which is around 1.3 pounds).
I got a graceful but data-free answer. I was hoping they were exploring alternate energy, but it sounded like they were mainly focused on lower power usage by the computers (which is tough with high end scientific computers).
For what its worth, my guess is that they're somewhere over 10,000 tons of CO2/yr (that'd equate to a 10MW facility), which is similar to driving a car 20 or 30 million miles.