Blog dedicated primarily to randomly selected news items; comments reflecting personal perceptions

Tuesday, May 24, 2016

Our Changing World

"It's clear that the warming temperatures and extraordinary drought are major players here."
"We probably wouldn't be seeing the scale of some of these fires if it weren't for these factors."
Thomas W. Swetnam, emeritus scientist, ecology, University of Arizona
Increases in wildfire activity for 2030 and 2090, from Canadian
Climate Centre general circulation model (GCM).
"Implications of changing climate for global wildland fire"
Flannigan et al. 2009.

The extent and ferocity of the wildfire that struck northern Alberta early this month, necessitating an evacuation of 90,000 residents from Fort McMurray and environs struck firefighters as a demon all their efforts were unable to vanquish. The lightning-swift spread of the fire that consumed all in its deadly path, leaving long-time firefighters in dread of the menace it represented informed them that they were dealing with an event whose destructive fierceness knew few precedents.

The fire and the smoke it bellowed out in great, black gusts of burnt detritus seemed to those who were involved in trying to contain it, a living, crafty entity whose purpose it was to oppose every known manoeuvre useful in the past to fight such runaway fires. They spoke of the fire as having the properties of an evil demon, and from their experience it must have seemed justified; an evil sorcerer had convinced nature to threaten the lives of humans and other animals, consuming vast tracts of boreal forest.

A site near Sandy River, NWT suffered a severe wildfire in 2014, only 10 years after a previous burn. With all the new growth consumed, the area is now like a desert. Photo Credit: Dennis Quintilio

Such wildfires, environmentalists warn, are on the increase. Great areas of the Canadian boreal forest are in danger of that kind of spontaneous combustion. And when they break out during hot, dry, windy conditions and they're far from human habitation the emergency response to tackle them loses its impact. Those fires and the onset of insect populations threatening the boreal forest, denuding conifers of their needles and killing the trees reflect beetles now able to withstand the rigours of milder winters.

It is not only Canada's boreal forests that are under threat in the changing environment where climates have undergone huge alterations affecting the health of the landscape. About 28 million hectares of boreal forest burned in 2012's Russia, according to newly released statistics relating to isolated areas of Siberia. Most of the boreal forest in the United States is in Alaska, and it experienced its second-largest fire season on record in the year just past, with 768 fires turning over two million hectares to charcoal.

A wildfire at Lake Baikal in Siberia in 2015. In Russia, extensive mining and drilling for fossil fuels are damaging the forest. Credit Anna Baskakova/The Siberian Times
Global warming which is universally suspected of having brought more extreme weather conditions like torrential rains, or drought, the warming of the oceans and melting of icecaps and glaciers is also thought to have brought together conditions that make these wildfires so difficult to predict and control. Northern regions of the world appear to be particularly hard hit by climbing temperatures with snow cover prematurely melting leaving forests to dry out earlier making them susceptible to excess heat and lightning strikes.

In the 1990s, Brian J. Stocks, a scientist with the Canadian Forest Service, wrote a dire forecast warning of such an outcome in the foreseeable future and beyond. Now retired and working as a consultant, he has warned that more is yet to come, and worse than has been experienced: "We're kind of at a crossroads. We anticipate more fires, and more intense fires, in the future", he emphasizes. And that is very, very bad news since we are so  hugely dependent on these forests as carbon sinks.

The world's forests help offset the rise of greenhouse gases. They absorb a huge part of the carbon dioxide resulting from the burning of fossil fuels. Scientists are concerned that if the wildfires continue to destroy huge tracts of forest, alongside the devastation caused by insects which at one time would die off during cold winter months and now no longer do -- moving steadily north, in their path of destruction -- carbon stored in the forests will be released to the atmosphere as carbon dioxide.

Acceleration of the pace of global warming is not a good news story, nor is the fact that winds carrying soot from these northern fires onto ice sheets in Greenland creating a darkened surface causes it to absorb more sun's heat, and ending up melting that ice. This has happened; soot contributed to the surface of the Greenland ice sheet melting in 2012, the first such event since 1889. Should that continue to happen, the sea level could be raised by over six meters.

Data coming out of Alaska suggests that wildfires have been more dire than what has occurred in the previous 10,000 years. While forest fires occured naturally throughout the history of the boreal forest, recent decades inform that their frequency and intensity has grown exponentially. Earlier melts of spring snowpack across the Northern Hemisphere as a result of global warming is thought to be leading to the hot, dry conditions hastening these ferocious wildfires.

A fire in the boreal forest of Alaska last week. The state had its second-largest fire season on record in 2015, with 768 fires burning more than five million acres. Credit Bill Roth/Alaska Dispatch News

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