Wasn't sure about that one Macro. My first reaction was to google "Position of magnetic pole effects on climate" .
www.ipgp.fr/fr/are-there-connections-between-the-earths-magnetic-field-and-climate" These seem to correlate with significant climatic events in the eastern North Atlantic region. A proposed mechanism involves variations in the geometry of the geomagnetic field (f.i. tilt of the dipole to lower latitudes), resulting in enhanced cosmic-ray induced nucleation of clouds. No forcing factor, be it changes in CO2 concentration in the atmosphere or changes in cosmic ray flux modulated by solar activity and geomagnetism, or possibly other factors, can at present be neglected or shown to be the overwhelming single driver of climate change in past centuries. "
According to these guys the magnetic pole drift is competing with C02 as the main suspect driving the current climate drift!
AC will merely oscillate the pole but if you can show that your proposed coast to coast DC will bend the pole in a climate-cooling direction. Win , win, you'll get funding for sure.
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However, another thought. If sending power DC from east to west is beneficial, when WA has all the sunlight all the good would be undone. We'd need two transmission lines, ACDC. AC west to east. If power shifting was done this way world wide, need to do some sums.