Is there a number between 20,000 (which seems so low as to not be a serious suggestion I have ever seen anyone make) and "growing forever"--for which there was

Is there a number between 20,000 (which seems so low as to not be a serious suggestion I have ever seen anyone make) and "growing forever"--for which there was that great analysis done by the physicist arguing with the economist, to whom they were trying to explain that even small amounts of growth forever led to us boiling our oceans with heat output to satisfy everyone's energy needs--that would work for you?