The only things that can change that resultant point of temperature equilibrium are changes in solar radiance coming in or changes in overall atmospheric density which affect the radiant energy going out. (newclimatemodel.com)
Let me repeat: the south pole of Mars is getting less sunlight in 2005, because of variation in solar radiance over the 11 year cycle, then it did in 2001 and 2003. (realclimate.org)
This is the case even if there is a change in the mean radiance over decades (between solar cycles) because the year - to - year variation within a cycle is larger than the variation between cycles, and we measured solar radiance in 1999 - 2005. (realclimate.org)