In this final part of my climate paper, I talk about extreme events and other scare stories, and about how some scepticism is the result of the excessive zeal of climate change proponents.
Disasters that have nothing to do with a changing climate are ascribed to “climate change” as a means of raising awareness about the supposed threats. Nothing illustrates this aspect of the debate better than the ongoing accent on “extreme events.” A violent storm, such as the recent Sandy that struck New York, is immediately seized upon as evidence of “climate change.”
Weather is
ever variable. The vigour of every natural phenomenon has a wide range. Many
phenomena, for example rainfall, are best described by a distribution which is
very strongly skewed. Such distributions
are quite counterintuitive when it comes to trying to define what constitutes
“extreme”.
The problem
is how to decide the width of the ‘normal’ range, a decision essential for
describing an event as abnormal or ‘extreme’, that is, lying outside the normal
range. A lot of data is necessary to
define ‘normal’, which implies that data must be collected over a long period.
The long period may exceed a human lifetime.
If so, then few living individuals can have experienced the truly
“extreme” events – and an event much less than extreme may be seized upon as an
example of an extreme event when in fact it is no such thing.
In the case
of storm Sandy, there has been an assessment of the intensity of all hurricanes
and “post-tropical storms” (of which Sandy was one) that made landfall on the
continental United States between 1900 and 2012. The data are shown in Figure 8[i].
A person
born in 1900 would probably have experienced their most extreme event in
1936. However, that person might have
lived to the age of 106, and would have seen two stronger storms. That might
have convinced him/her that the world was getting worse. He/she would have been wrong, of course – the
random nature of extreme events would have fooled them.
 |
| Figure 8. Power dissipation index of storms which made landfall on the US, 1900-2012 |
This
illustrates quite nicely how long one must wait before one can determine even
the 100-year event – and how just because there has been such an event, another
nearly as bad can turn up in less than 100 years after that! The statistics of
extreme events are counterintuitive, and very long baselines are needed before it
is possible to decide if something is extreme or not.
There has been extensive concern about extreme events,
partly because almost every day somewhere on the globe there will be an event
that might be describable as ‘extreme’. The IPCC has issued a special report on
the subject[ii].
It can probably best be described as ‘delphic’ – a series of very cautious
pronouncements that can be interpreted in different ways, depending on your
viewpoint. Probably the best measure of the extent to which extreme events
should be viewed as likely to be caused by climate change comes from a study of
deaths caused by severe weather[iii]. The results are shown in Figure 9.
It is clear
that the absolute number killed each year has dropped since the 1920’s. In relative terms, the drop has been even
more dramatic, from a peak of 241 per million to 5 per million. At this low rate, extreme
weather no longer presents the same risks as faced previous generations.
 |
| Figure 9. Deaths and death rates per million people from extreme weather events |
The reasons
for this steep decline are several. One
is vastly better weather prediction, so that there is now adequate warning
about possible extreme weather conditions.
Secondly, there is much better communication of impending severe
weather. Finally, with improved knowledge of severe conditions, mankind has
learned to design structures that protect us from the hazards. If ‘climate
change’ is having any effect, it is invisibly by this measure.
The final
scare story that needs to be laid to rest is that of species extinction as a
result of climate change. The popular press reports this regularly. “’Climate
change now represents at least as great a threat to the number of species
surviving on Earth as habitat-destruction and modification,’ said Chris Thomas,
a conservation biologist at the University of Leeds in the United Kingdom. - - the
predicted range of climate change by 2050 will place 15 to 35 percent of the
1,103 species studied at risk of extinction. The numbers are expected to hold
up when extrapolated globally, potentially dooming more than a million species.
”[iv]
However, science prefers predictions that are testable. A recent serious study concluded
that “Surprisingly, [there is no] straightforward relationship between
local extinction and limited tolerances to high temperature.” [v]
Indeed, this follows from common sense.
Figure 10 shows the average monthly conditions for Cape Town. The boxes show the average daily maxima and minima, the lines
show the highest and lowest temperatures ever recorded, and the lower and upper
horizontal lines reflect the annual average temperature in 1900 and 2000
respectively.
 |
| Figure 10. Monthly temperatures in Cape Town, and annual averages in 1900 and 2000 |
It is reasonable to ask how the relatively small average
temperature change can be detected by organisms that every year are likely to
be exposed to changes some 50 times larger, to which they seem perfectly
adapted.
The final
reason for ongoing scepticism is the behaviour of some of the proponents of the
climate change thesis. It starts with
the Intergovernmental Panel on Climate Change.
It has become a political body rather than a technical body. The best illustration of this is the
publication of the Panel’s reports. It
is preceded by the publication of a summary for policy makers. This summary
often differs in material respects from the findings of the main report, and
invariably puts a politically correct slant on what is supposed to be a
dispassionate review of the scientific literature[vi].
The IPCC’s
work is not aided by the fact that much of the work reported is not scientific,
but reproduced from activist literature.
The Canadian journalist Donna Laframboise has documented this problem in
detail[vii].
For
example, she tracks how a relatively unknown professor of epidemiology, Anthony
McMichael, who had written a polemic in 1991, became a lead author of the
chapter on malaria and the health effects of climate change, even though he had
no professional publications about malaria and even though some of his
conclusions were rejected by members of the Panel who were world experts on the subject.
Sections of
McMichael’s book appeared almost verbatim in the IPCC’s Assessment Report in
1995. This led directly to the thesis that global warming will increase the
spread of malaria. There is no evidence that this is likely, because malaria
has been known in cold climates for centuries. Moreover, the spread of malaria
is known to be almost entirely a function of social conditions and public
health.
The fight
against malaria is not helped by those who claim that climate change is part of
the problem. If they had their way, the accent would be on addressing climate
change rather than fighting malaria. This illustrates a danger of accepting a
possibly flawed thesis too uncritically – resources may be diverted from
essential activities affecting the lives of millions in the hope that there
will be a positive impact on putative risks that might possibly affect
billions. Before taking such a decision,
one needs to be very certain indeed that the putative risks can be avoided by
the diversion of resources.
Another
reason for scepticism is that the debate about climate change has revealed some
major imperfections in the scientists themselves. Some players on the
human-induced climate-change playing field have shown themselves to be only too
human in the defence of the indefensible. For example, two scientists did what
scientists are supposed to do – they peer-reviewed the work of some 200 other
scientists[viii].
They reported that:
“Across the world, many records
reveal that the 20th century is probably not the warmest nor a uniquely extreme
climatic period of the last millennium.”
This was totally contrary to the
thesis that today’s warming was exceptional. Accordingly the believers in
human-induced change forced the editor of the journal that had published the review
to resign, and went out of their way to try to destroy the reputations of the
two authors. All this (and more) was
revealed when a series of emails found its way into the public domain from the Climate
Research Unit at the University of East Anglia[ix].
The world
is slightly warmer than a century ago.
The carbon dioxide levels of the atmosphere are increasing. Plants are doing better than before because
of the higher carbon dioxide[x].
The sea is rising in a barely detectable way. Climatic disasters are no worse
than previously. The animal kingdom is being squeezed by the growth of a single
species, us, but that has nothing to do with global warming.
And that is
why there is a climate of scepticism.
[i] http://rogerpielkejr.blogspot.com/2012/11/us-hurricane-intensity-1900-2012.html
Accessed January 2013
[ii] IPCC, 2012: Managing the
Risks of Extreme Events and Disasters to Advance Climate Change Adaptation.
A Special Report of Working Groups I and II of the Intergovernmental Panel on
Climate Change [Field, C.B. et al (eds.)]. Cambridge University Press,
Cambridge
[iii] Goklany, I.M. Wealth and Safety: The
Amazing Decline in Deaths from Extreme Weather in an Era of Global Warming, 1900–2010.
Reason Foundation, Washington DC and Los Angeles, CA, 2011
[iv] http://news.nationalgeographic.com/news/2004/01/0107_040107_extinction.html
Accessed January 2013
[v] Cahill, A.E, Aiello-Lammens, M.E.,
Fisher-Reid, M.C., Hua, X., Karanewsky, C.J., Ryu, H.Y., Sbeglia, G.C,
Spagnolo, F., Waldron, J.B., Warsi, O. and Wiens, J.J. How does climate change
cause extinction? Proc. Royal Soc. B 2012 doi: 10.1098/rspb.2012.1890
http://rspb.royalsocietypublishing.org/content/early/2012/10/15/rspb.2012.1890.full Accessed
January 2013
[vi] http://www.publications.parliament.uk/pa/ld200506/ldselect/ldeconaf/12/1207.htmAccessed January 2013
[vii] Laframboise, Donna The Delinquent
Teenager who was mistaken for the world's top climate expert. Ivy Avenue Press,
Toronto 2011. ISBN: 978-1-894984-05-8
[viii]
Soon, W. and Baliunas, S. Proxy
climatic and environmental changes of the past 1000 years. Climate Research Vol.
23, pp89–110, 2003
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