The case against AGW / global warming / "climate change" being caused by human activity, part 17

The theory that human activity is causing the earth's climate to warm by more than an insignificant amount is called "AGW"--anthropogenic global warming--and for this theory to be correct, four things must be true: 
   1.  the amount of CO2 in the atmosphere must be increasing;
   2.  the climate must actually be warming by a significant amount;
   3.  any such warming must be caused by CO2, rather than other gases;
   4.  a significant percentage of this CO2 must be emitted by the burning of carbon fuels.

Measurements (in Hawaii) have shown that atmospheric CO2 has been increasing for the past 50 years or so, and that fact alone causes concern among members of the public and the scientific community.  Nevertheless, many, many things could refute this theory:

   1.  If it can be shown that the earth's climate had natural cycles of average global temperature before humans started burning a significant amount of carbon fuel;
   2.  If it can be shown that at many times in the past, increasing CO2 did NOT precede a temperature increase;
   3.  If it can be shown that gases *other than* CO2 have a much larger "greenhouse effect";
   4.  If it can be shown that the climate is not actually warming significantly.

I've done several posts showing how NOAA and NASA have actually *changed* temperatures originally reported, making the new "official" temp different from what the person reading the thermometer actually wrote down.  In every case, the changes made by both agencies have made temperatures from the last couple of decades warmer and temps from decades earlier cooler, which has the effect of making the trend look like the climate is warming a LOT more than it really is.

This time I'd like to call your attention to a different metric of climate change:  Glacier retreat.

A mainstay of the AGW crowd is that all over the world, glaciers are retreating!  Which obviously means the globe is getting warmer, right?  But take a look at the historical locations of glacier faces {"terminii") at Glacier Bay, Alaska, below.  As you see, the glaciers there have been retreating since the bay was first mapped in 1760 or so.

So...these glaciers were retreating since 1760.  But humans didn't start burning gazillions of tons of fossil fuels until 190 years later.  But...but...but... if CO2 causes global warming, how can that be?
 
And that's the point.