What about ablation and/or ablative thrust using lasers?
You'd need to fuel a laser platform, but it could target debris over a huge region. The goal would be to both reduce size and to gently nudge smaller debris to lower (and atmosphere-intersecting) orbits.
You don't need to put a laser in space to do this.
You build a ground based laser, and fire it at objects when they're approximately directly overhead. Pushing upwards on the object basically rotates it's orbit so one side of it will not be lower into the atmosphere.
You build a ground based laser, and fire it at objects when they're approximately directly overhead. Pushing upwards on the object basically rotates it's orbit so one side of it will not be lower into the atmosphere.