* The first humans to arrive in the Americas would have had to contend with a much more challenging environment. The cold climate would have made it difficult to find food and shelter, and the lack of water would have made it difficult to travel and settle in many areas.
* The development of agriculture would have been much more difficult. The cold climate would have made it difficult to grow crops, and the lack of water would have made it difficult to irrigate fields.
* The spread of humans throughout the Americas would have been much slower. The thick ice sheet in the north would have blocked the migration of people from Asia, and the harsh conditions in the south would have made it difficult for people to travel and settle in many areas.
* The development of complex societies in the Americas would have been much more limited. The cold climate and the lack of resources would have made it difficult for people to build large and complex societies.
In short, if the ice age had not ended, the development of human societies in the Americas would have been much more difficult and would have taken a very different path.