The geographic limits of the South Atlantic Anomaly, as defined by radiation
damage, are compared to contours of geomagnetic total field
intensity, as defined by the 1995 IGRF, for the present and recent
past. The most likely secular variation of the geomagnetic field is estimated
and used to extrapolate the geomagnetic field to the year 2100. This indicates
that radiation damage to spacecraft and humans in space will likely increase
and to cover a much larger geographic area.