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<div>The truth is often more complicated than what is presented with political or ideological bias. Both climate change and "overabundant fuels" are considered as variables contributing to the dramatic increase in Western US wildfire activity in the article below:
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<h2>Warming and Earlier Spring Increase Western U.S. Forest Wildfire Activity </h2><strong>A. L. Westerling,<sup>1</sup><sup>,2</sup><sup><a href="http://www.sciencemag.org/cgi/content/full/313/5789/940#COR1">*</a></sup>
H. G. Hidalgo,<sup>1</sup> D. R. Cayan,<sup>1</sup><sup>,3</sup> T. W. Swetnam<sup>4</sup> </strong></div>
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<div><a href="http://www.sciencemag.org/cgi/content/full/313/5789/940">http://www.sciencemag.org/cgi/content/full/313/5789/940</a></div>
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<div>We compiled a comprehensive<sup> </sup>database of large wildfires in western United States forests<sup> </sup>since 1970 and compared it with hydroclimatic and land-surface<sup> </sup>data. Here, we show that large wildfire activity increased suddenly
<sup> </sup>and markedly in the mid-1980s, with higher large-wildfire frequency,<sup> </sup>longer wildfire durations, and longer wildfire seasons. The<sup> </sup>greatest increases occurred in mid-elevation, Northern Rockies
<sup> </sup>forests, where land-use histories have relatively little effect<sup> </sup>on fire risks and are strongly associated with increased spring<sup> </sup>and summer temperatures and an earlier spring snowmelt.<sup>
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<div>Robust statistical associations between wildfire<sup> </sup>and hydroclimate in western forests indicate that increased<sup> </sup>wildfire activity over recent decades reflects sub-regional<sup> </sup>responses to changes in climate. Historical wildfire observations
<sup> </sup>exhibit an abrupt transition in the mid-1980s from a regime<sup> </sup>of infrequent large wildfires of short (average of 1 week) duration<sup> </sup>to one with much more frequent and longer burning (5 weeks)
<sup> </sup>fires. This transition was marked by a shift toward unusually<sup> </sup>warm springs, longer summer dry seasons, drier vegetation (which<sup> </sup>provoked more and longer burning large wildfires), and longer
<sup> </sup>fire seasons. Reduced winter precipitation and an early spring<sup> </sup>snowmelt played a role in this shift. Increases in wildfire<sup> </sup>were particularly strong in mid-elevation forests.</div>
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<div>However, the same study states:</div>
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<div>We describe land-use history versus climate as competing explanations,<sup> </sup>but they may be complementary in some ways. In some forest types,<sup> </sup>past land uses have probably increased the sensitivity of current
<sup> </sup>forest wildfire regimes to climatic variability through effects<sup> </sup>on the quantity, arrangement, and continuity of fuels. Hence,<sup> </sup>an increased incidence of large, high-severity fires may be<sup>
</sup>due to a combination of extreme droughts and overabundant fuels<sup> </sup>in some forests. </div>
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<div>Thus, although land-use history<sup> </sup>is an important factor for wildfire risks in specific forest<sup> </sup>types (such as some ponderosa pine and mixed conifer forests),<sup> </sup>the broad-scale increase in wildfire frequency across the western
<sup> </sup>United States has been driven primarily by sensitivity of fire<sup> </sup>regimes to recent changes in climate over a relatively large<sup> </sup>area.<sup> </sup></div>
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<div>The overall importance of climate in wildfire activity underscores<sup> </sup>the urgency of ecological restoration and fuels management to<sup> </sup>reduce wildfire hazards to human communities and to mitigate<sup>
</sup>ecological impacts of climate change in forests that have undergone<sup> </sup>substantial alterations due to past land uses. At the same time,<sup> </sup>however, large increases in wildfire driven by increased temperatures
<sup> </sup>and earlier spring snowmelts in forests where land-use history<sup> </sup>had little impact on fire risks indicates that ecological restoration<sup> </sup>and fuels management alone will not be sufficient to reverse
<sup> </sup>current wildfire trends.<sup> </sup></div>
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<div>Vision2020 Post: Ted Moffett</div>