 As the Iowa
floods recede, leaving behind the impact of what the Iowa City Gazette
describes as the "500-year flood event," the world records another
sampling of climate change weather horror. It's Al Gore's nightmare
scenario happening today, right before our eyes.
As Roger Pielke
reports in today's Junk Science Week special, any such link between
climate change theoretical models and today's weather, while often
made, are really not supportable. Mr. Pielke, a political scientist at
the University of Colorado, says claims to such links give climate
modelers an aura of credibility that is not deserved. As he puts it,
there's nothing that could take place over a period of a decade or less
"short of an ice sheet advancing on New York" that would be
"inconsistent with climate change model predictions."
If all
weather events are consistent with climate models, then no current
weather events serve as any useful indicator of climate change or as a
sign that climate change is happening.
This would be news to my
local all-news radio station, which is constantly inundating listeners
with stories of our "wild and wacky weather." Any sudden downpour and
thunderstorm is treated like a staggeringly new development in local
climate behavior.TV news reports on weather developments routinely
treat extreme storms, floods, droughts, heat waves, hurricanes and cold
snaps as portents of ominous change in our climate.
Often, the
implied cause of the allegedly wild weather -- man-made climate change
-- isn't explicitly identified. Just the tone of the coverage of
weather -- as strange, anomalous, weird, unprecedented -- is enough to
convey the climate change message that the weather is now somehow
unnatural.
On CNN, during the network's extensive coverage of the
Iowa floods, the possibility that man-made climate change might be
behind the disaster isn't always raised directly. Instead, the message
is conveyed with the network note that the Iowa flood will be part of
its grand endless special series --Planet in Peril!
Canadians are
familiar with Andrew Weaver, of the School of Earth and Ocean Sciences
at the University of Victoria. As Canada's official climate modeler,
he's a regular on news reports linking weather events with long-range
climate change. "We're only now seeing the very, very early stages of
global warming. There's much more in store, even as we stabilize to the
levels of greenhouse gases that exist today," he told the CBC earlier
this year in the wake of one of Canada's coldest winters.
When
the weather is cold, it proves climate change is taking place. And if
it's hot, it proves climate change is taking place. Seven of the eight
warmest years on record have allegedly occurred since 2001 and the 10
warmest years have all occurred since 1997. The global average
temperature is said to have risen between 0.6C degrees and 0.7C degrees
since the start of the 20th century, with the rate of increase since
1976 estimated at three times faster than the century-scale trend.
"When you see these numbers, it's screaming out at you, 'This is global
warming,' " said Mr. Weaver last year. "It's the beginning and it's
unequivocal."
The Iowa floods
have produced numerous reports, especially on the green blog sites,
that climate change is the cause. The New York Times quotes two
scientists lending support to the idea that the floods were linkable to
climate change. One of the scientists, Henry F. Diaz, of the U. S.
Earth Systems Research Laboratory in Boulder, Colorado, nimbly fudged
the issue. "As everyone notes," he told the Times, "any particular
occurrence of a climate anomaly cannot be shown in any deterministic
fashion to have occurred as a result of global warming."
That
sounds clear enough: No event like a flood can be pinned on climate
change. But then Mr. Diaz slips a gear: "However, the continuous change
in the probability distribution of these various phenomena, as
greenhouse forcing proceeds full speed ahead, indicates that such
extreme events may be samples from the projected future distributions."
So the Iowa floods "may be samples" of what climate change would bring
in the future.
If all this is confusing, that's because many
climate scientists and climate modelers have been far from clear on the
true nature of their climate models. In Mr. Pielke's view, claims to
immediate and short-term climate model predictive accuracy are
dangerous. Exaggerations and false claims can create policy reactions
that can be more damaging than helpful when, as Mr. Pielke believes we
should, we make preparations for climate change.
In the case of
the Iowa floods, simply blaming climate change for local weather events
that cannot be linked to climate change could lull people into
believing that the solution is to fix climate change through radical
carbon policies-- rather than improve flood preparations. Mr. Pielke
also calculates that flood damage in the United States has been
declining over the last 70-plus years (see chart below).
Iowa
floods are nothing new. Stories of failed levee maintenance,
inappropriate settlement and development of flood regions are now
emerging. Declining investment in bridge and river services create
increased vulnerability to the inevitable and normal floods. A focus on
climate change, which cannot be accurately singled out as the cause,
can do no good. Source
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