Tag Archives: forest fires

Global wildfires are in decline

Stefan H. Doerr, Cristina Santín. Global trends in wildfire and its impacts: perceptions versus realities in a changing world Philosophical Transactions of the Royal Society B; Biological Sciences DOI: 10.1098/rstb.2015.0345

Wildfire has been an important process affecting the Earth’s surface and atmosphere for over 350 million years and human societies have coexisted with fire since their emergence. Yet many consider wildfire as an accelerating problem, with widely held perceptions both in the media and scientific papers of increasing fire occurrence, severity and resulting losses. However, important exceptions aside, the quantitative evidence available does not support these perceived overall trends. Instead, global area burned appears to have overall declined over past decades, and there is increasing evidence that there is less fire in the global landscape today than centuries ago. Regarding fire severity, limited data are available. For the western USA, they indicate little change overall, and also that area burned at high severity has overall declined compared to pre-European settlement. Direct fatalities from fire and economic losses also show no clear trends over the past three decades. Trends in indirect impacts, such as health problems from smoke or disruption to social functioning, remain insufficiently quantified to be examined. Global predictions for increased fire under a warming climate highlight the already urgent need for a more sustainable coexistence with fire. The data evaluation presented here aims to contribute to this by reducing misconceptions and facilitating a more informed understanding of the realities of global fire.

Mis-information campaign about California wildfires

“With wildfires engulfing over 620,000 acres of California, there’s been a concerted media campaign to single out man-made global warming as the primary force behind the deadly blazes. But that’s not what the data suggests, according to University of Washington climate scientist Cliff Mass.”

click here

Wildfires are in decline globally

“As usual with climate fear articles like this one in the L. A. Times the scientific reality present a far different picture. The latest scientific study completed by the Royal Society concludes that global wildfires are in decline.” click here

Forest mismanagement fuels California fires

“The Little Hoover Commission (LHC), an independent California oversight agency, has been documenting forest mismanagement in the Golden State for decades. LHC described California’s Timber Harvest Plan in 1994 as an “inadequate tool” for balancing environmental and economic needs.” click here

Wildfires are not increasing as climates change

 “Global area burned appears to have overall declined over past decades, and there is increasing evidence that there is less fire in the global landscape today than centuries ago.” click here for WUWT discussion

Stefan H. DoerrCristina Santín. Global trends in wildfire and its impacts: perceptions versus realities in a changing world. Philosophical Transactions of the Royal Society B. Biological SciencesDOI: 10.1098/rstb.2015.0345

Wildfire has been an important process affecting the Earth’s surface and atmosphere for over 350 million years and human societies have coexisted with fire since their emergence. Yet many consider wildfire as an accelerating problem, with widely held perceptions both in the media and scientific papers of increasing fire occurrence, severity and resulting losses. However, important exceptions aside, the quantitative evidence available does not support these perceived overall trends. Instead, global area burned appears to have overall declined over past decades, and there is increasing evidence that there is less fire in the global landscape today than centuries ago. Regarding fire severity, limited data are available. For the western USA, they indicate little change overall, and also that area burned at high severity has overall declined compared to pre-European settlement. Direct fatalities from fire and economic losses also show no clear trends over the past three decades. Trends in indirect impacts, such as health problems from smoke or disruption to social functioning, remain insufficiently quantified to be examined. Global predictions for increased fire under a warming climate highlight the already urgent need for a more sustainable coexistence with fire. The data evaluation presented here aims to contribute to this by reducing misconceptions and facilitating a more informed understanding of the realities of global fire.

National Forest Fire Acreage Burned Decreasing

“According to the National Interagency Fire Center, 9.4 million acres burned in the US this year. This is down 80% since the 1930’s.” click here

Wildfire Alters DBP Precursors

Wang JJ, Dahlgren R, Ersan M, Karanfil T, Chow AT. Wildfire alters terrestrial precursors of disinfection byproducts in forest detritus. Environmental Science and Technology. 2015 Apr 20.

Wildfire occurrence and intensity are increasing worldwide causing severe disturbances to forest watersheds used for potable water supply. The effects of wildfire on drinking water quality are not well understood, especially in terms of terrestrial dissolved organic matter (DOM) and DOM-associated formation of disinfection byproducts (DBP). As the forest floor layer is a major source of terrestrial DOM, we investigated characteristics and DBP formation of water extractable organic matter (WEOM) from the 0-5 cm depth of non-burned detritus (control) and burned detritus with black ash (moderate severity) and white ash (high severity) associated with the 2013 Rim Fire in California. Spectroscopic results suggested that the aromaticity of WEOM followed white ash > control > black ash and fluorescence region II (excitation 220-250 nm; emission 330-380 nm) of the emission-excitation-matrix was identified as a potential burn severity indicator. Compared to the control, WEOM from white and black ashes had lower reactivity in forming trihalomethanes (55%-of-control) and haloacetic acids (67%-of-control), but higher reactivity in forming the more carcinogenic haloacetonitrile after chlorination (244%-of-control) and N-nitrosodimethylamine after chloramination (229%-of-control). There was no change in reactivity for chloral hydrate formation, while WEOM from black ash showed a higher reactivity for haloketone formation (150%-of-control). Because wildfire consumed a large portion of organic matter from the detritus layer, there was lower water extractable organic carbon (27%-of-control) and organic nitrogen (19%-of-control) yields in ashes. Consequently, the wildfire caused an overall reduction in water extractable terrestrial DBP precursor yield from detritus materials.

Click here for paper (fee).