We discovered this on YouTube, in a series called "Climate Denial Crock of the Week." The video maker is Peter Sinclair, an advocate of environmental awareness and energy alternatives. Here's what he has to say about it:
"Climate Deniers S. Fred Singer and Dennis Avery make their livingby confusing and obfuscating the science of climate change. Theirlatest book, Unstoppable Global Warming every 1500 Years, is acompendium of vintage as well as cutting edge climate crocks. Let'sfind out who they are and how they are bamboozling their audience."