Isostasy is the condition in which the lighter crust of the earth floats on the denser lithosphere below. If ice weighs down a region, that crust will sink lower into the earth and rise after the ice melts. If more crust builds up in an area because of subduction or continental collision, then deeper roots will form that will float the upper crust higher and form mountains. If the upper mountains are eroded, mass will be removed and isostasy will cause the remaining crust to float even higher. A feedback is that erosion leads to mountains which increase erosion.
Mountains also lead to cooler conditions, more snow, higher albedo, and yet cooler conditions.
The snow leads to glaciers, more erosion, and higher mountains. Cooling of the planet in the last 20 million years has coincided with increased mountain building. Another connection is in the carbon cycle. During periods of volcanism more CO2 is added to the atmosphere leading to warmer conditions. But after volcanism, increased weathering of mountains takes CO2 out of the atmosphere through carbonate and silicate weathering so having mountains can lead to cooler conditions to glaciers to isostatic response to higher mountains.