From Rhetoric to Reality on GW
In an undergraduate course we run on the "Global Environment and
Human Health" here in the University of Bristol, we set about, with a
group of 24 medical students, to try and reach balanced conclusions about
the science of climate change. But in seeking to diagnose the ailments of
the planetary system we soon found we couldn't really understand the
As is so often the case with medicine also, we relied on secondary
sources; books, articles, IPCC summaries (both sceptical and fanatical).
We did however have one unique source of knowledge in the form of Prof
Paul Valdes, one of our Geography professors and co-author of the latest
What a breath of fresh air! He explained the political process
whereby painstaking research is transmogrified into summaries, editorials
and media rhetoric. He said for instance that no climate scientist of
repute thought that Hurricane Katrina could be pinned on GW.
He explained that the rise in global CO2 is nearly 100% anthropogenic
(isotopes have proved this), that the "Medieval Warm Period" was a
European not a global warming and that the 2007 reworking of the
(in)famous "Mann et al" paper convincingly demonstrates a late 20th rise
in average global temperature (the hockey-stick curve much doubted by
The message is, unfortunately, not clear-cut. Clouds are a mystery.
Sea-level rises exceptionally hard to predict because we are not yet sure
what is happening with the glaciers. His uncertainty made me more inclined
to believe what he was certain about.
I now, unlike before, don't think it is scientifically reasonable, or
even responsible, to doubt the reality of GW. The students reached this
same conclusion. The impact of that reality and what we can do about it
are even more complex questions. But given the possibilities for a major
screw-up in the global system a "precautionary" approach seems wise,
Competing interests: No competing interests