Time of the great freeze

I recall reading this book long ago and thinking it was pretty good.
I wanted to see if it held up so I read it again.
And it doesn't hold up.
There is actually very little plot and the characters were hard to tell apart.
Most of the Earth is under a mile of ice and our heroes are exiled to the surface from New York
because they dared to communicate with people in London.
While traveling across the ice to England, they meet a surprising number of people living on the ice.
They encounter people who have reverted back to early hominid culture, another group who are similar to pre-Columbian Native Americans and some Vikings.
Somehow these people live exclusively on moose and/or walruses (the moose somehow live on algae)
and have fires and wooden ships even though there are no trees on the ice.

Most of these encounters are violent but luckily one of our heroes knows Judo and they have some
kind of combination flame thrower/disintegrator ray.
They travel in solar powered sleighs where they are exposed to the elements, kind of like a
big snowmobile.

All of this sounds silly to me now, but teenage me thought it was a cool adventure.
Young me was also oblivious to the sexism in the book.
A lot of SF books from the 1960s and before and women in only stereotypical roles.
But this book essentially has no women in it.
About the only reference to women is when one of the primitive peoples they encounter is described as ‘screaming like a woman'.

So I was disappointed in the book and can't recommend it.
I have a few others that I am rereading and I hope they hold up better.

“It's time to come up out of the ground. Time for men to breathe the air again, to walk under the open sky.”

The sun and all its planets had been engulfed by a vast cloud of cosmic debris, and dust motes were screening and blocking the sun's radiation from Earth. And so immense was the cloud that it would take centuries for the Solar System to pass entirely though it! The result is a new Ice Age. Self-contained, atomic-powered cities were built, capable of surviving under the ice for an indefinite length of time. The underground city of New York was ready for occupancy in the year 2297, about a century after the Earth had entered the cloud of cosmic dust. And now it was 2650 a.d., and the underground cities were more than three hundred years old. They had long since lost contact with one another, and by now all such contact was taboo. The New Yorkers, whose number had grown to 800,000 and then had been fixed there by law, were warm and happy in their underground hive. But after 300 years the ice is finally rolling back. Who cared for the outside world? Why go back to that vale of tears? ⠀
⠀
Silverberg's post-apocalyptic adventure story was really good for me. A nice piece of fiction from one of the Grand Masters of the genre. This is the kind of book that makes me love speculative fiction even more, and in this case not only because of the global reaction to an impending ice age but also because of the anthropological implications. Human beings can get used to everything, right? Give resilience some time and new standards will emerge, we might even forget the surface and open spaces and become agoraphobic beings living comfortably in underground cities (which reminds me of Asimov's “The Caves of Steel”). Fortunately, some would not settle. Some would try to search for other survivors and even surface and travel thousands of miles across frozen lands and oceans just for the sake of human contact. This is their story.