My mistake. What drives climate is the subject, not global warming. I still don’t see how magnetic pole drift affects climate, though.
Change in pole strength directly effect the amount of charged particles entering the earth’s atmosphere. Charged particles from the sun & cosmic rays. The earth’s field as well as the Sun’s field - which also changes, Jupiter’s & even Saturn’s field! They all change over time!) deflect these particles. Primarily its the earth’s field, weak field more particles are let in and we have more clouds hence cooler earth. Clouds reflect light & heat back. (Think of charges particles going through a cloud chamber, they leave a vapor trail - a cloud!). Stronger the field fewer particles fewer clouds more light & heat is absorbed. There seems to be places along the galactic rim as the solar system rotates around the galaxy where there are higher rates of charged particles (cosmic rays). These “patches” correlate to major cooling events particularly if the earth’s field strength is down.