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--></style><title>Western U.S. fire risk: Who saw it coming, and
when?</title></head><body>
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<div><font face="Geneva" size="-1" color="#000000">"A current
warming trend in AMO suggests that we may expect an increase in
widespread, synchronous fires across the western U.S. in coming
decades."</font></div>
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<div><font face="Geneva" size="-1" color="#000000">Proceedings of the
National Academy of Sciences</font></div>
<div><font face="Geneva" size="-1" color="#000000">January 9,<b>
2007 </b></font></div>
<div><font face="Geneva" color="#000000"><b><br>
Contingent Pacific-Atlantic Ocean influence on multicentury wildfire
synchrony over western North America </b></font></div>
<div><font face="Geneva" size="-1" color="#000000">Thomas Kitzberger,
Peter M. Brown, Emily K. Heyerdahl, Thomas W. Swetnam, and Thomas T.
Veblen</font><br>
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<div><font face="Geneva" size="-1"
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<div><font face="Geneva" size="-1" color="#000000">Widespread
synchronous wildfires driven by climatic variation, such as
those that swept western North America during 1996, 2000, and
2002, can result in major environmental and societal impacts.
Understanding<b> relationships between continental-scale patterns
of drought and modes of sea surface temperatures (SSTs)</b> such as
El Nino Southern Oscillation (ENSO), Pacific Decadal Oscillation
(PDO), and Atlantic Multidecadal Oscillation (AMO) may explain how
interannual to multidecadal variability in SSTs drives fire at
continental scales. We used local wildfire chronologies reconstructed
from fire scars on tree rings across western North America and
independent reconstructions of SST developed from tree-ring
widths at other sites to examine the relationships of multicentury
patterns of climate and fire synchrony. From 33,039 annually
resolved fire-scar dates at 238 sites (the largest paleofire record
yet assembled), we examined forest fires at regional and
subcontinental scales.<b> Since 1550 CE, drought and forest fires
covaried across the West, but in a manner contingent on SST
modes.</b> During certain phases of ENSO and PDO, fire was
synchronous within broad subregions and sometimes asynchronous
among those regions. In contrast, fires were most commonly synchronous
across the West during warm phases of the AMO. ENSO and PDO were
the main drivers of high-frequency variation in fire
(interannual to decadal), whereas the AMO conditionally changed
the strength and spatial influence of ENSO and PDO on wildfire
occurrence at multidecadal scales. A current warming trend in
AMO suggests that we may expect an increase in widespread,
synchronous fires across the western U.S. in coming
decades.</font></div>
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<div><font face="Bookman Old Style" color="#000000">"How does one
justify trying to cope with what may be intractable problems? The very
nature of the question belies its origins in the assumption of science
that one has to believe that all problems are solvable."<br>
<br>
Seymour Sarason. The Nature of Problem Solving in Social Action.<i>
American Psychologist.</i> April, 1978<br>
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" 'Triage' is a dirty word in some conservation circles, but like
many dirty words, it describes something common. Whether they admit it
or not, conservationists have long had to make decisions about what to
save.<br>
<br>
"As more and more admit it, open discussion about how the
decisions are best made -- by concentrating on particular species, or
particular places, or absolute costs, or any other criterion --
becomes possible. Whichever criteria come into play, one thing remains
constant. The decisions have to be made quickly."<br>
<br>
Emma Marris, "What To Let Go."<br>
NATURE November 8, 2007</font></div>
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