My solution to the same problem would be to reduce insolation by deploying large shades in earth orbit to cast shadows. Something like humongous, gigunda ultrathin and ultra light reflective parasols to reflect excess sunlight away.

This is almost possible with today's technology (we're not moving an entire planet around the solar system) and has the added advantage that the shades could be moved around, replaced, maintained, or discarded, as needed. without much permanent damage to us.

Whenever possible, all engineering fixes to any problem should be made reversible, just in case we change our minds later on.