Santa's workshop.
Polar wandering might be an alternative explanation for the alleged "global warming" recently reported on Mars. I've always felt the usual suspect for this effect, an increase in solar output, was too miniscule to produce effects visible from Earth over just a few years.
On Earth, polar wandering is limited to just a few meters per year and appears to be random; on Mars, the effect might be much more pronounced and cumulative and have climatological consequences over shorter timescales.