Something a reader sent me reminded me of something I had forgotten. He wrote:
A glacier is a river of ice flowing slowly to the sea, fed by the head waters due to a build up of pressure, the same as a river of liquid water. They even have currents and flow around boulders that will not break loose and the bottom and sides flow slower than the middle. A glacier that has receded is due to a lack of new moisture at the source.
The central point in that is that glacial advance and retreat is primarily a function of precipitation. Which means that a lack of snowfall is what causes a glacier to shrink/retreat. Warmists, by contrast, regularly attribute glacial retreat to warming, completely ignoring the fact that glaciers around the world wax and wane all the time, even when temperatures are plateaued.
And the really interesting thing about that is what causes fluctuations in snowfall. There are many local factors but if we are talking about global influences, what causes reduced snowfall is COOLING. A warming world evaporate more water off the oceans and that water vapor would fall again as rain/snow. Conversely, a cooler world would evaporate less ocean water, leading to reduced precipitation.
Greenies rarely these days talk about melting glaciers except in the case of Greenland but next time you hear a Greenie talking about a shrinking glacier somewhere say to them: "So we are having global cooling now, are we?" It won't help your friendship, though. I was once on quite good terms with a man who had a solid scientific background when some shrinking glaciers came up in conversation. I started to explain to him the role of precipitation but he cut the conversation rather short and I have never heard from him again. Warmists are fragile souls. How sad is it that some simple scientific facts can upset someone!