Ah! The Ice Ages!
I presume that what we are discussing involves a two mile thick chunk of Ice still covers central North America and much of Europe, that sealevels are greatly depressed, that there is still a land bridge at the bering straights and that the North Seas is above water in enough places that walking to Britain is very easy?
There might still be civilizations. What we know as "civilization" arose in Mesopotamia, the Nile and Indus Valleys, and in China, and those places weren't glaciated. Not only that, they had far more water and rainfall than is found at present, so an emerging civilization and agriculture MIGHT in fact have been easier.
So far as I know, our knowledge of the human condition as found from 12,000 to 6000 years ago is very limited. Whole civilizations of whom we have never found a trace COULD have existed. If Civilization first emerged under conditions that included ample rainfall, high fertility of the soil, and a lush climate, why then there you have it---The Garden of Eden, which unfortunately dried up and became buried under sand dunes when the rainfall ceased and weather patterns changed, after the Ice receded.
If the Ice had not melted and retreated to the poles, all of the arid, desert places such as the Sahara, Arabia, Mesopotamia, and Northern Mexico/SouthWestern USA would be wet, semi-tropical, verdant places.