The USA and Russia are seriously considering building a tunnel under the Bering Sea to link Siberia with Alaska, a rail tunnel obviously. The cost? A mere $100 billion, chickenfeed at the world level.
This is a fantastic move and suggests that at least at government level people are thinking beyond oil and the obvious demise of air travel. The intention is that we will be able to travel from London to New York by rail, not really that far fetched as the first stretch of water (the English Channel) already has a tunnel under it and the Bering Tunnel will only be about twice as long.
We're off to New York in December, by air of course, but I very much doubt our kids will be able to do the same thing, and their kids certainly won't be able to. But they will still be able to make (an albeit longer time-wise) trip around the world, train from London to New York, then sailing ship across the Atlantic. All is not lost! And it will be so much more fun doing it the modern way.
The journey across Siberia and Alaska will be fantastic. worth doing for the scenery alone. Perhaps it will incorporate the White Pass and Yukon Railroad (in the pictures) on its journey through North America.