Is science getting it right?

Question It's this measure of uncertainty that is the greatest concern. Can you see an end to that?

There's no complete escape of uncertainty. (I'm about to post something about that to the ClimateConcern list.) Debunkers have used demands for tighter certainty to keep scientists scrambling for each next new round of next-better evidence, which has certainly made the science tighter, but also tied up the budget for studying second-order impacts such as species distributions/extinctions, crop hazards, disease risks, ad nauseum.

Question The scientists seem to be playing catch up rather than predicting what is going to happen by using their models. This means we do not have sufficient understanding of the problem yet. Items like the more rapid loss of the polar icecaps, warmer Arctic and the first hurricane in the South Atlantic seem to take them by surprise and they have to reconsider their models and timescales.

Yup, and they know it. For one example, the National Academy of Sciences said a few years back that scientists' models tend to underestimate a) the speed and b) the extent of change. And the scientists themselves have confirmed that on many occasions, as when a team set up to study likelihood of insect-borne disease reported that it is already detecting trends it had not expected to see until 2080. One major result is that we'll all be seeing an IPCC Fourth Assessment, due out in early 2007, that will be noticeably different than its 2001 Third Assessment.

In talks to university and conservationist groups, I've been saying that we have committed the climate to a very bad situation, and, given political/social realities, may not even avoid committing it to a much worse one. But I'm not exactly at the forefront here, because as long ago as 1970 at least a few voices were saying (see the September 1970 issue of Scientific American) that our mucking around with the carbon cycle might prove fatal to our species.

Recent work like Harte's below, tends toward confirmation of scientists' concerns that are actually rather old, but long-challenged, long-derided, and even suppressed in the current political climate.

Lance

In a message dated 17/10/2006 22:25:46 GMT Daylight Time, lance@wildrockies.org writes:

" it is likely that the future will be hotter than we think."

Geophysical Research Letters

33, L10703, doi:10.1029/2005GL025540.

Missing feedbacks, asymmetric uncertainties, and the underestimation

of future warming

Margaret S. Torn and John Harte

Received 19 December 2005; revised 17 March 2006; accepted 24 March

2006; published 26 May 2006.

ABSTRACT:

Historical evidence shows that atmospheric greenhouse

gas (GhG) concentrations increase during periods of

warming, implying a positive feedback to future climate

change. We quantified this feedback for CO2 and CH4 by

combining the mathematics of feedback with empirical ice-core

information and general circulation model (GCM)

climate sensitivity, finding that the warming of 1.5 -4.5 degrees C

associated with anthropogenic doubling of CO2 is amplified

to 1.6-6.0 degrees C warming, with the uncertainty range deriving

from GCM simulations and paleo temperature records.

Thus, anthropogenic emissions result in higher final GhG

concentrations, and therefore more warming, than would be

predicted in the absence of this feedback. Moreover, a

symmetrical uncertainty in any component of feedback,

whether positive or negative, produces an asymmetrical

distribution of expected temperatures skewed toward higher

temperature. For both reasons, the omission of key positive

feedbacks and asymmetrical uncertainty from feedbacks, it

is likely that the future will be hotter than we think.

If you'd like to see pdf file of full Torn & Harte article, just ask.

Lance Olsen

--

Cold Mountain, Cold Rivers

Working at the Crossroads of Environmental and Human Rights since 1990

PO Box 7941

Missoula Montana 59807

(406)728-0867

Posted to the Yahoo Group ClimateConcern 16/10/06