The bottom line is this, many have speculated that MMGW is possible, but none have actually proven it is the primary or even a major mechanism for climate change or even present over the last 16 years of intensive study.
No warming for 16 years despite dire and incorrect predictions by many.
We could be entering a cooling phase or it could be a pause in the 15,000 year cycle of warming. Nobody knows, but they do know warming stopped for 16 years.