TLDR: All energy usage produces waste heat, and while right now the planetary heating from altering the atmospheric composition (GHG emissions) dwarves that from waste heat, even if we were to switch all our energy production to "green" energy tomorrow, assuming continued exponential increase in energy consumption as at present, in one century waste heat alone would account for about 1K of planetary heating. Any technological civilization that follows a similar trajectory of exponential increase in energy consumption would make its planet uninhabitable within 1000 years.
TLDR: All energy usage produces waste heat, and while right now the planetary heating from altering the atmospheric composition (GHG emissions) dwarves that from waste heat, even if we were to switch all our energy production to "green" energy tomorrow, assuming continued exponential increase in energy consumption as at present, in one century waste heat alone would account for about 1K of planetary heating. Any technological civilization that follows a similar trajectory of exponential increase in energy consumption would make its planet uninhabitable within 1000 years.