[GMoromisato]

Satellites below 500 km do not need energy to reenter. Their orbits will naturally decay from friction with the upper atmosphere.

CO2 emissions from reentering satellites is far lower than CO2 emissions from terrestrial datacenters. If you need 1,000 tons of satellite for a 100 MW of compute, you're not going to get more than 1,000 tons of CO2. In fact, you'll get much less since metal doesn't release CO2 when it melts.

1,000 tons of CO2 is negligible compared to 40,000 tons at launch and invisible compared to 1.5 million tons for a terrestrial datacenter.