[Vision2020] Western U.S. Forest Wildfire Activity

Wed Oct 24 14:28:18 PDT 2007

Again with the selected experts. 

Ok...so you win on that front in that I refuse to play along.  Point is, which you REFUSE to acknowledge, this is not the first time earth's history has seen this type of activity nor will it be the last.

So please - continue on with your doomsday scenarios and good luck in reducing your stress level over it.  It simply is not worth the effort to continue this discussion.  I will just go back to what I started some time ago - deleting your e-mails as they come up.

And to set things clear - I am NOT saying we do not need to make changes.  I just will not fall into the "Chicken Little" mold of looking at things.  What you are doing is not improving anyone's life; certainly, it is not improving yours.

J  :]

Date: Wed, 24 Oct 2007 13:45:27 -0700
From: starbliss at gmail.com
To: jeanlivingston at turbonet.com
CC: vision2020 at moscow.com
Subject: Re: [Vision2020] Western U.S. Forest Wildfire Activity

All-

Regarding the ongoing Southern California fires, and the very important issue of Western US fire potential (especially in Idaho) and causes in general, the following fact and science based sources are critical.

Read about the record drought and heat waves for Southern California (both this year), coupled with the findings from the research on Western USA fires, in the Science magazine article below, co-authored by the scientist, Thomas Swetnam (University of Arizona), who I referenced at the start of this thread, who was interviewed on CBS 60 Minutes last weekend on the subject of wild land fire, with astonishing timing, given the explosion in the Southern California fires that occurred immediately after:

http://www.terradaily.com/reports/Western_US_States_Swelter_Under_Record_Heatwave_999.html

Parched California has driest 'rainy season' on record

Los Angeles (AFP) July 1 - Los Angeles suffered through the driest rainy season on record in 2007, marking the least amount of precipitation here in the 130 years 

http://www.noaanews.noaa.gov/stories2007/s2838.htm

In Los Angeles, the lack of rainfall led to the driest water-year to date for the city since records began in 1877. From July 1, 2006, through the end of March, downtown Los Angeles had received only 
2.47 inches of rain, almost one foot below the normal amount of rainfall for the period.

In the West, where mountain snowpack is relied upon to supply water needs throughout the region, below-average rain and snowfall have become increasingly common. In only two of the past nine years has snowpack on April 1 been at or above the long-term average in at least half the region.

--------------

For those who wish to skip most of the Science magazine article, here is a critical finding of their research, indicating human land use is not the cause of the documented increase (note not the cause of the "increase," not that humans do not start fires) in Western USA fires in recent decades:

http://www.sciencemag.org/cgi/content/full/313/5789/940

We compiled a comprehensive database of large wildfires in western United States forests since 1970 and compared it with hydroclimatic and land-surface data. Here, we show that large wildfire activity increased suddenly
 and markedly in the mid-1980s, with higher large-wildfire frequency, longer wildfire durations, and longer wildfire seasons. The greatest increases occurred in mid-elevation, Northern Rockies
 forests, where land-use histories have relatively little effect on fire risks and are strongly associated with increased spring and summer temperatures and an earlier spring snowmelt.

--------------------

I will excerpt a few more paragraphs from this article:

Science 18 August 2006:
Vol. 313. no. 5789, pp. 940 - 943
DOI: 10.1126/science.1128834

Prev | Table of Contents | 
Next 
Research Articles

Warming and Earlier Spring Increase Western U.S. Forest Wildfire Activity A. L. Westerling,1,2*
 H. G. Hidalgo,1 D. R. Cayan,1,3 T. W. Swetnam4 

http://www.sciencemag.org/cgi/content/full/313/5789/940

We compiled a comprehensive database of large wildfires in western United States forests since 1970 and compared it with hydroclimatic and land-surface data. Here, we show that large wildfire activity increased suddenly
 and markedly in the mid-1980s, with higher large-wildfire frequency, longer wildfire durations, and longer wildfire seasons. The greatest increases occurred in mid-elevation, Northern Rockies
 forests, where land-use histories have relatively little effect on fire risks and are strongly associated with increased spring and summer temperatures and an earlier spring snowmelt.

------

Snow carries over a substantial portion of the winter precipitation that falls in western mountains, releasing it more gradually in late spring and early summer, providing an important contribution
 to spring and summer soil moisture (35). An earlier snowmelt can lead to an earlier, longer dry season, providing greater
 opportunities for large fires due both to the longer period in which ignitions could potentially occur and to the greater drying of soils and vegetation. Consequently, it is not surprising
 that the incidence of wildfires is strongly associated with snowmelt timing. 
Changes in spring and summer temperatures associated with an early spring snowmelt come in the context of a marked trend over the period of analysis. Regionally averaged spring and summer temperatures for 1987 to 2003 were 
0.87°C higher than those for 1970 to 1986. Spring and summer temperatures for 1987 to 2003 were the warmest since the start of the record in 1895, with 6 years in the 90th percentile—the most
 for any 17-year period since the start of the record in 1895 through 2003—whereas only 1 year in the preceding 17 years ranked in the 90th percentile. Likewise, 73% of early years 
since 1970 occurred in 1987 to 2003 (Fig. 1). 
--------
If the average length and intensity of summer drought increases in the Northern Rockies and mountains elsewhere in the western United States, an increased frequency of large wildfires will 
lead to changes in forest composition and reduced tree densities, thus affecting carbon pools. Current estimates indicate that western U.S. forests are responsible for 20 to 40% of total U.S
. carbon sequestration (38, 39). If wildfire trends continue,
 at least initially, this biomass burning will result in carbon release, suggesting that the forests of the western United States may become a source of increased atmospheric carbon dioxide
 rather than a sink, even under a relatively modest temperature-increase scenario (38, 
39). Moreover, a recent study has shown that warmer, longer growing seasons lead to reduced CO2 uptake in high-elevation forests, particularly during droughts (
40). Hence, the projected regional warming and consequent increase in wildfire activity in the western United States is likely to magnify the threats to human communities and ecosystems, and substantially increase
 the management challenges in restoring forests and reducing greenhouse gas emissions. 
------
Vision2020 Post: Ted Moffett

_________________________________________________________________
Boo! Scare away worms, viruses and so much more! Try Windows Live OneCare!
http://onecare.live.com/standard/en-us/purchase/trial.aspx?s_cid=wl_hotmailnews
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.fsr.com/pipermail/vision2020/attachments/20071024/04a021ed/attachment.html 