The crucial issue surely is that we cannot be certain. The situation
is hugely complex. I think I agree that we should do all we can to
slow down the rate of change however it seems unlikely that
there is any way that society can reverse the direction of change
(more carbon dioxide, more warming) Hopefully the optimistic
view from the Guardian article will be the major effect but
whatever it will not turn out positive for everyone / everything
(That much is certain?)

My personal concern is that with the warming the energy flows
through the atmosphere will become substantially greater and thus
weather will be, on average, more violent. This seems rarely to be
considered - or perhaps I read the wrong papers.

From a school teaching viewpoint the antagonism is between
exploring possibilities and probabilities and expecting pupils to
focus on 'facts' to gain high grades in tests and examinations.
There seems to be no credit given for uncertainty and pupils are,
not surprisingly, low on patience when it comes to having opinions.
Mostly teachers pretend that they know all the answers?

Alan

To: Biology Tutors Discussion List <BIOTUTOR-L@...>
Copies to: science-education <science-education@...>
From: Keith Taber <kst24@...>
Date sent: Sat, 27 Apr 2002 13:55:06 +0100
Subject: [science-education] Sometimes it may be sensible to play safe
when unsure - Re: GCSE
English and Global warming
Send reply to: science-education@...

Okay (1), I strongly think that pupils should be taught
science with 
a much stronger emphasis on its modelling nature, and
less as if it 
deals with facts. This (IMHO) is one of the major
limitations of 
current science education.

Okay (2), we really don't know for sure about when, if
or how global 
warming will proceed.

BUT: given that if global warming due to human activity
does occur to 
any significant extent - and perhaps much, much quicker
than climate 
change has done in the past:
a) the world's ecosystems will change significantly;
b) there is likely to be considerable amount of
extinction of many 
different types of species;
c) this could conceivably include extinction of human
beings.

Now (b) is not certain, and (c) certainly (sic) not. We
do believe 
(i.e. our current models, based on very imperfect
knowledge) that (i) 
life on earth as it now is (e.g. range and variety) has
probably 
depended upon the inherent nature of a system which has
in-built 
checks and balances - i.e. for such a system to evolve
and survive 
potential catastrophes it would need to have various
negative 
feedback cycles built ('evolved') in; that (ii) whilst
small 
perturbations are 'absorbed' by the system, large
changes may tend to 
switch the system into the next stable state available
(where life on 
earth continues, but often with a significantly
different overall 
pattern!); that (iii) Venus provides a model of how an
earth-like 
planet may turn into a very unearth-like planet when
climate change 
occurs without the protection of a sufficiently varied
and 
established biota.

I don't know
how much global warming is occurring;
how much this is due to humans or would be happening
anyway;
how much or how quickly the average temp. may be rising;
how much local variation in effect there will be;
how much human-influenced extinctions have weakened the
inherent 
protective nature of the biosphere;
how much of the world may become more/less habitable
for people;
how much the balance of plants that we depend upon will
change (e.g. 
C3 vs C4? - not my area of expertise);
how likely it is that we may experience 'runaway'
effects where 
positive feedback cycles becomes more important than
the negative 
ones - as appears to have made Venus so inhospitable;
etc., etc.

HOWEVER: even if we are unsure (and we need to make
that clear to 
pupils) let's not just shrug out shoulders and say 'it
may not 
happen'.

Many regular smokers don't die of smoking related
diseases;
Many alcohol abusers are not killed by alcohol realted
conditions;
It is possible to have unprotected sexual intercourse
with an HIV 
positive person without necessarily contracting HIV;
Some regular extreme sun-worshippers do not suffer skin
cancers;
Some LSD trips are very positive experiences. etc.

In each of these cases we do not understand all the
factors operating 
in enough detail to advise pupils on exactly how much
of a danger 
they (specifically) might be in - so we work with the
balance of 
probabilities on the basis of best information - and
advise pupils 
accordingly.

We do not have thousands of earths to observe to judge
the true 
dangers of global warming - so perhaps we should play
safe?

Russian roulette gives some people a thrill, without a
bullet in the 
brain...at least the first few times.

Or am I missing the point here?


Keith

(Yes, I'm a veggie, often wear sandals, don't have a
car, and listen 
to those noisy 70s prog records. And I'm lucky to work
on a campus 
with lots of lovely trees. But I don't think any of
this makes me a 
bad, or a stupid, person.)





>I'm pleased to see this. The GCSE syllabuses included
global warming
>years ago, long before there was any consensus amongst
scientists. Why?
>There isn't consensus now and yet it's still there.
>
>The sanctimonius tree-huggers and lentil-eaters who
are happy to see
>pupils taught dubious science should be ashamed of
themselves. The basic
>grounding in science we give our young folks should be
free of
>politically motivated material or it should be taught
in a more balanced
>way. This document is no more biased than our own
syllabuses but at
>least it appears to be introduced for discussion.
>
>
>Andy


-- 


Dr. Keith S. Taber
http://www.educ.cam.ac.uk/staff/taber.html
University Lecturer in EducationUniversity of Cambridge Faculty of
EducationHomerton College site
Hills Road
Cambridge CB2 2PH



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Alan Goodwin
Manchester Metropolitan University
Institute of Education
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