Earth Aurora (Auroral X-ray emission observed from Earth's north polar region.)
Originally uploaded by Smithsonian Institution.
The [Van Allen] belts are a hazard for artificial satellites and moderately dangerous for human beings, difficult and expensive to shield against.
There is a proposal by the late Robert L. Forward called HiVolt which may be a way to drain at least the inner belt to 1% of its natural level within a year. The proposal involves deploying highly electrically charged tethers in orbit. The idea is that the electrons would be deflected by the large electrostatic fields and intersect the atmosphere and harmlessly dissipate.
Besides that I personally can't imagine the risk we'd be taking by making such a huge change to the makeup of space just outside our atmosphere (can some of you more astronomy/science-minded folks chime in?), I wouldn't want to lose the auroras!