Challenge to Debate Natural Climate Change Deniers

I still haven’t watched Chasing Ice; I’ve had too much good science to read and ponder this past week to waste time on an entertainment that purports to be science by recording a short time period of glacier retreat. Where were these climate change “documentary” film makers when the Muir Glacier, Glacier Bay, Alaska, retreated 60 miles in the 1800’s and only 6 miles since?

The most interesting study I read blows away the extremely limited and misinterpreted proxies that underpinned Al Gore’s “Hockey Stick” in An Inconvenient Truth.  As we all remember from my previous letters, the Hockey Stick did not display the well-documented higher warmth of the Medieval Warm Period (850-1350AD) or the cold of the Little Ice Age (1350-1850AD), and without disclosure the Hockey Stick eliminated tree ring samples and replaced them with instrumental records when recent tree rings showed cooling when alarmist scientists wanted warming.

However, torturing tree rings to make them divulge desired outcomes can’t stand against natural evidence. Nature provides us unequivocal records of past greater warming: coral mounts rising high above current sea level. Simply, coral does not grow above water, so high-and-dry coral skeletons prove Earth has had warmer periods.  One such previous warm period was the Eemian, only 125,000 years ago; coral mounts formed during the Eemian show sea level was almost 30 feet higher, indicating temperature about 10°F above the present. Other coral mounts show sea levels up to 10 feet higher during three recent warming periods – the Holocene Climatic Optimum, Roman, and Medieval, during the past 8,000 years.

Since atmospheric CO2 never rose above 280ppm during these earlier warm periods, it would give me great pleasure to debate a natural climate change denier and begin by asking: Did CO2 cause these warmer periods?

How?