I'll reread the chapter later today to refresh my memory, but my first thought about the canal is that they would try icebreakers to attempt to free up the canal. If that's not possible for some reason, then, aside from the problems Tom has already mentioned would be some increase in shipping costs for goods that have to travel around the southern tip of South America, unless everything is solar-powered by then (probably). Also, more danger travelling that route since the winds down there can be severe. If planes are also solar powered, then the canal becomes less relevant, since good can be shipped via Fedex. :-)
My biggest question is how the world came to be frozen over. I think a reader would really like an answer to that to be able settle into a good sci-fi story.
My other question was where the world is growing food if it's close to freezing over. There would be massive wars around the world fighting over scarce food-growing land. Most the human race should be dead or dying. Come to think of it, if the Panama Canal freezes over, then even the Equator (one of the warmest places on Earth) has frozen over, so most of the rest of the world, both north and south, would have frozen over as well, including most freshwater lakes and rivers.
Even if the Equator is still warm enough for food growth, then everything will be clearcut for farmland, unless food growth moves underground. The scale of engineering for the latter would be astounding, although I use it on one of the worlds in my own book. It's doable in my case, because I don't have billions to feed, just millions. For underground food growth, here, too, I suggest solar power instead of oil to power the hydroponics, since oil reserves are probably gone by the 24th century.
Given all that, you may want to leave the Panama Canal clear of ice, to allow for food growth on land around the Equator.
I did quite a bit of research for terraforming worlds, since I have about 60 inhabited planets so far in my galaxy. It turns out, the vast majority of Earth's oxygen came from microorganisms in the oceans (farting oxygen). So, to really terraform a planet, life should already have a long-established foothold on your prospective planets (hundreds of millions of years, if not billions; I don't recall the exact number). You also need a way to rapidly grow organisms for soil formation, since natural soil formation on Earth takes 1000 years per inch (doublecheck me on that one too). Obviously, if microscopic life already exists, then you risk all humans and human food crops being unable to survive on those planets. My book is more space opera than sci-fi, so I glossed over some of those problems, since that level of detail would slow my book's Star Warsian pace.
Obviously, you don't need to answer all these questions in chapter 1, but I think it would really help to give us the cause of this worldwide disaster up front, otherwise you're asking us to accept a premise without explanation. A supervolcano might be able to do it. Or, an asteroid. In the latter case, humans would probably have excellent asteroid detection and deflection technology by the 24th century, although something kicked out of the asteroid belt by Jupiter would come at us so quickly, deflection may not be possible in time.
Dirk
