Pre agriculture society has built Goḱbi Tepe, and other "stone age monuments", its not far fetched that they diverted rivers and thus caused desertification of some area which may had other effects on global climate.

Wasnt the Sahara a swamp pre-agriculture?

Also, the "pre-agriculture = low population" is just a speculation, it could have been far higher population in some areas and we wouldnt have any evidence for it today. See for example Americas before conquestadors, there were areas with millions of people, and not all doing agriculture or even horticulture.

The best areas which could have supported a very high population have been destroyed, all the best areas were taken by "civilized" war people, and now the only nomads/hunter gatherers left are in far-reached shitty areas.

You're confusing anthropogenic climate change (pollution) with natural climate change (end of ice age).

I was replying to:

> Maybe this latest global warming/climate change, is not the first time humans had an impact on climate? Its certainly not the first time any species had an impact on climate, looking at you cyanobacteria.