Climate crisis: world is at its hottest for at least 12,000 years – studyJanuary 31, 2021
I think you’re mixing up some terms. When historians & archaeologists say “civilization” they are specifically referring to groups of humans organized under a political structure that live mostly sedentary lives that rely on agriculture. Generally there the group has a writing system and some degree of organized religion, which is often a key part of the political structure.
The definition isn’t perfect and there’s constant debate about what is needed to be considered a civilization. The idea is expanding though because the politics+writing+agriculture+religion definition describes “Western” civilizations most effectively but it struggles the further you get.
The Inka, for example, were undeniably a massive, complex society with organized religion & agriculture but they didn’t have a writing system as we’d consider it. (They used colored, knotted string for records, called Qipu.)
Without a doubt humans have been intelligent and organized for 10s of thousands of years, but we don’t have evidence (yet) for a “civilization” older than Egypt, Sumeria, and those surrounding cultures.