I should acknowledge what some of you are no doubt thinking: OK, cruises might be fun, but they're not the most environmentally responsible way to vacation. Cruise ships used to routinely dump crap into the ocean (they're supposed to follow rules about it now) but they also used to do things even stupider and more wantonly destructive, all in the name of entertaining tourists.
One day we visited Hubbard Glacier in Yakutak (pronounced "Yak Attack") Bay. As we approached, we were allowed to go up to the front of the bow so we could lean over the railings and stare right at this massive chunk of ice. It's a damn impressive sight: 76 miles long and six miles wide at the point where it meets the ocean, and every so often it will calve off icebergs the size of a ten-story building. If you saw the chunk fall off, you'd shout, "Oh! Look!" as you pointed; if you didn't, you'd look where someone was pointing and say, "Oh, crap." You actually had to WATCH the glacier and WAIT if you wanted to see it DO anything.
And apparently that patience which is now necessary used to be considered an avoidable inconvenience. While hanging out on the bow, I talked to a guy who was on his third Alaskan cruise. He said that the first two times he went, someone would bombard whatever glacier they were visiting with sonar so that it would calve more often and more dramatically. But then someone else pointed out that since 95% of the world's glaciers are receding on their own, it probably wasn't wise to help them, and the practice was abandoned.
A few days ago, Chris posted an entry about the fact that being crappy residents of this planet should motivate us to STOP being crappy residents instead of rushing about space looking for a new home to move to after we've completely trashed this one. (Not that he's opposed to space exploration--he says that about a dozen times and people still seemed to miss it.) But he went so far as to compare humanity to a cockroach infestation, and both his basic point and that comparison pissed a lot of people off. Personally I thought the post was both funny and apt, and the fact that we would speed up the dissolution of the polar ice caps just because its cool to watch, is one more reason I think that.