The string (X / Y °C / decade) gives the associated 100 year and 50 year linear slopes in degrees Centigrade per decade. (folk.uib.no)
Try to randomize the solar data and then put them on a linear slope equal to the actual linear slope found in the solar data and do again your calculation, then let me know if you find the same good pattern correspondence I found. (realclimate.org)
Now you have the physical cause for the convection in the troposphere and the linear slope observed there, it is caused by the physics of the transmission of thermal radiation through the air. (notrickszone.com)