Why are the can allen radiation belts important to life on earth?

Van Allen Radiation Belts








The belts are not important to life on the surface of the Earth, but you can turn this around and say that, if there were no belts, the earth would not have a magnetic field. This means that cosmic ray particles would be free to collide with the earth's atmosphere in greater numbers, and from these you would get a higher background level of secondary 'air shower neutrons' which would lead to higher background radiation doses on the surface. The Belts do not directly impact human life, but if they were gone, this would imply that other effects would have to be in effect as a consequence of what the larger system would look like.