Construct lots of gigantic heatsinks, attached to the earth but stretching up above the atmosphere.
Wouldn't the heatsinks need to have very high temperature conductivity? Do we have suitable materials today? Are we talking about mountain-masses of superconductors?
Allow me to draw your attention to the first word in the title of the thing we're commenting on.
Yes, I think they would need to conduct well. I don't think they'd need to be superconductors. I have made no attempt to do the calculations that would be needed to figure out what would actually be needed.
Mine was to work tax policy to incentivize companies to make all their packaging shiny and white, incentivize people to litter, and disincentivize everybody from recycling.
My friend's was to use a giant rocket to push the earth farther away from the sun