Earlier quoted context omitted.
Hilariously, a dyson sphere operating at 5% capacity would still generate more power every second than humanity currently generates in 10,000 years.
But at even just 4%, the thermal emissions from a partial Dyson swarm would still be enough to heat Earth by twice what anthropogenic climate change has managed so far: https://www.sciencedirect.com/science/article/pii/S092702482...
Luckily with that kind of energy you can do absolutely insane things, like build planet-sized sunshades or push the earth to a more distant orbit. These challenges can be engineered around.