According to Dr. Kristen Gates, all we need to do is attach a giant drag-causing balloon to the defunct spacejunk, then sit back and watch it burn as it slowly enters the earth's atmosphere. Interesting concept Doctor, but I suggest we keep exploring our options until we come up with something that involves a powerful burning laser.
The "GOLD" envelope she's proposing -- or the Gossamer Orbit Lowering Device -- is basically the toughest balloon in the world. It's sent up to orbit in a box no larger than a suitcase, and then it's fastened to a dead satellite or a piece of space junk. After that? It inflates into a massive balloon, enveloping whatever it's designed to lower.
Lower into the atmosphere, that is, where the piece of debris will burn up and trouble the Earth's orbit no more. The balloon's size amplifies the amount of drag acting on the space junk already, which slowly decays an object's orbit.
Sure we could just use boring round balloons, or we could -- wait for it -- use giant balloon animals. You know how many people would buy telescopes just to see a giant wiener dog dragging a dead satellite to its fiery death? I'm talking double-digits.