[apt-apt-apt-apt]

I will solve this for you so you can worry about other things like the obsolescence of humanity and killer drones/bots.

In 200 years, we will have tamed the ability to generate energy efficiently and have relatively intelligent drones. These drones in swarms can track space debris, match their horizontal speed and push them out to outer space. Space debris will not be an issue. Maybe they can also take little bubbles of greenhouse gases and drop them out into space too.