Note that, although our current warming trend began in the late 1600s, the glacial retreat wasn't initiated until the early 1800s. That is because it took 100-plus years for the warming to cause more summer melting than winter accumulation.
A highlight of many Alaskan cruises, Glacier Bay is often pointed to as a warning of our "sins of emission." However, retreat of this glacier began in the late 1700s and had retreated some 50 miles before significant additions of CO2 in the mid-20th century. There have been only about 10 miles of retreat since (Seramur 2001).
Glacial facts simply do not support the theory that CO2 is the primary cause of modern warming.
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