Earth's Ultimate Environmental Problem

Over the next millennium and for the rest of human history, earth's major environmental problem will be warming due not to greenhouse gases but rather to increased waste heat from non-solar energy (initially petrochemical, but then fusion). The problem emerges when a world population in the tens of billions all enjoy an energy budget equivalent to levels in the industrialized West in 2000. Humans in 2000 consume 10 terawatts, wherease the total solar energy received by Earth is estimated variously at 109000 to 174000 terawatts. Ten billion humans at U.S. levels of energy use would consume 1000 terawatts. All the waste heat from all the energy uses adds up, and the laws of thermodynamics guarantee that energy use always creates heat exhaust. Heat pollution will have to be managed to prevent a runaway greenhouse effect like on Venus.