Geophysicist: Although scientists do not entirely agree on the causes of geomagnetic reversal, they do agree that the process has the potential for significant changes on the earth. A geomagnetic reversal occurs when the magnetic field of the earth adjusts in its orientation, so that the magnetic north becomes the magnetic south, and vice versa. What is more, studies indicate that the magnetic field is gradually losing its strength and that we might expect to see a reversal within the next few millennia. While this might not seem significant, the reversal of the magnetic fields would occur over a long period of time, leaving the earth potentially unprotected from the sun’s radiation.

Reviewing the information in the passage above carefully, which of the following represents the geophysicist’s primary argument?