X-Message-Number: 22655 Date: Mon, 06 Oct 2003 09:28:47 -0400 From: Keith Henson <> Subject: Re: CO2phobia [Steve Harris] At 09:00 AM 06/10/03 +0000, Steve wrote: snip >Ice ages are probably environmentally benign, since the come on and >retreat at time scales of 10,000 years or more, which time enough to let >plants and whole ecosystems migrate. But do that in 50 years, and temp >change from north to south generally outrun the plants, and then you get >mass extinction. Let's not go there, is my message. Steve, I am certainly not arguing with you about the undesirability of rapid climate changes. But the ice core record reflects the climate "chattering" into and out of ice ages on scales shorter than 50 years. At the end of the Younger Dryas cooling the climate warmed up 13 deg F in 50 years! The jump to ice age conditions is even faster. It seems there are large positive feedbacks involved that are poorly understood, but may involve abrupt shutoff of the massive movement of heat from the tropics to the far North Atlantic through the thermohaline circulation of the ocean. Here is a starting point: http://faculty.washington.edu/wcalvin/1990s/1998AtlanticClimate.htm thermohaline "ice age" in Google will take you into much of the rest of it. The consequences of an ice age for cryonics and humans in general are not good. Keith Henson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=22655