Worse than we think

At 04:00 24/10/2006, you wrote:

>Some "climate sceptics" make a big thing about the graphs of

>paleo-climactic temperature vs paleo-CO2 concentrations showing that

>in the past, increasing atmospheric CO2 concentration was apparently

>not the cause of warming in most cases, but instead, its concentration

>increased in response to rising temperatures. However, it is

>simply not true that this has any bearing upon the present

>circumstances, since in the past, only "natural" (if the Gentle Reader

>will indulge me in an artificial separation of "man-made" and natural

>matters, while recognizing of course that we are in fact as "natural"

>as anything else in the biosphere!) forces worked upon the biosphere,

>whereas in the present, anthropomorphic (i.e., caused by our species,

>Homo sapiens) causes are the driving factor behind the current rapid

>rise in ambieint average global atmospheric temperature - with the

>large increase in the greenhouse gas CO2, due to the burning of

>immense amounts of fossil fuels, being the principle forcing factor -

>in other words, you can indeed have two opposite sequences of events

>occuring, when the causes are different: in the past, increases in

>atmospheric CO2 were most often a result of rising global

>temperatures, whereas in the present, they are the principle cause of

>rising global temperatures: there is no contradiction or problem here:

>sometimes you're the windshield, sometimes you're the bug - causes can

>be interchangeable with effects, if the underlying driving forces are

>different.

>

> From a rapidly cooling New Scotland,

>Ross Mayhew.

>

In fact it may be even worse than this. The paleo-climate record seems to

show that rising temperatures release greenhouse gases which then have a

positive feedback on the warming that is happening. It is by no means

certain that our present day climate models have incorporated all of these

feedbacks in their projections, so the temperature rises we will eventually

experience from our anthropomorhic emissions may well be higher than those

models presently predict.

Chris

Dr Chris Hope

Judge Business School

University of Cambridge

Tel: 01223 338194

posted to Yahoo Group ClimateConcern