Let me point out how different the same study can look to different reporters in different arenas. Bettina Boxall, the Pulitzer Prize-winning LA Times reporter, looks at California in her big front-page story a week ago about long-term drought in California and SoCal, and finds little change in rainfall but substantial change in human behaviorContinue reading “Megadrought in the Southwest: LA Times vs NYT”
In a major study released today by the National Center for Atmospheric Research, scientists identify a climactic mechanism that increasingly appears to be blocking the kinds of storms that carry the most rain and snow from reaching California and the Southwest. From NCAR’s press release: “For the study, the researchers analyzed 35 years of dataContinue reading ““Ominous” news: CA faces megadrought”
The biggest and most horrifying story I stumbled across at the AGU involves forest mortality, as mentioned in this 2012 story in the NYTimes: Los Alamos National Laboratory studies tree deaths
It's good on the technical aspects, and really helped me understand the mechanism of "hydraulic failure" — how heat can not just challenge, but kill trees. The story doesn't want to be the last word on the subject, perhaps to its credit. It helps us understand the details:
To monitor how trees might succumb to thirst, researchers are measuring water flow inside each trunk. Normally ropes of water molecules are pulled up from the soil and roots by the atmosphere, moving through very small channels called xylem. When the air is warm, it exerts a greater pull on the water, increasing tension. If the tension gets high, the rope breaks and air is introduced. Like an embolism that can kill a person, air bubbles can block the flow of water. A tree can dry out and die.
It's helpful but I must say,it's not what the researcher in question, Nate McDowell, said at the at the AGU a couple of weeks ago. He framed it differently: as forest mortality.
In which case, the Times' approach almost literally misses the forest (mass mortality) for the trees (how individual trees succumb to climactic conditions).
In any case, talking to McDowell at the AGU, I mentioned that I was walking the Pacific Crest trail and had seen one burned out forest after another walking north through Southern California. Many huge fires have hit the trail before and after I have been walking just these past two years. Just weeks after myself and Chris Nottoli passed through the San Jacinto Mountains they were hit with a major fire, the Mountain fire, that consumed over 30k acres of pines near Idyllwild,and forced a long difficult roadwalk detour for those coming on the trail post-June 2013.
In Section C, I encountered another large area –more than 16k acres – of burned forest to the east and north of Big Bear Lake. Huge pines. Big Bear Fire. 2007. Took a full day or more to walk through the dead and twisted trees and scorched earth.
In Section D, coming down from the San Gabriel Mountains and turning north towards Agua Dulce, I had to walk through the vast scar left by the Station Fire of 2009, which burned over 160k acres and filled the sky with the life of thousands upon thousands of trees.
Then in Section E about thirty miles of trail north of Green Valley were completely destroyed by the Powerhouse Fire. A ranger told me that the soil itself had been changed by the extreme heat of the blaze. The trail had simply vanished.
Joe Anderson, who with his wife Terry takes care of hundreds of hikers passing through the trail near his town of Green Valley, told me that one hiker who did go through the burn emerged entirely blackened below his shoulders after walking through miles and miles of chaparral and pinyon pine turned to charcoal.
"It's like that the whole length of the trail, all the way up to Canada," said Nate McDowell, a couple of weeks ago, in the press room at the AGU.
I don't want to be alarmist, but McDowell and his friend and fellow scientist Craig Allen believe that the forests of the Southwest are doomed. They have a date in mind, for when they will have died off.
[for those curious about the mechanism of this catastrophe, the hypotheses and the studies, I've put some resources below the fold.]
Oh, c'mon. Now Accuweather is just getting silly: The last and strongest in the train of Pacific storms will unleash a new round of flooding rain, mudslides, feet of mountain snow, damaging winds and severe thunderstorms on California and the Southwest into Friday. Is is an all out weather war being waged by the atmosphereContinue reading “Accuweather: Storm is “war on the Southwest””
Hmmmmm…don't like the look of this. h/p: The stunningly great new site for the once-torpid US Global Change Research Program. Plus, you can find the full report here, or the executive summary here.
The big news in climate this week was the publication of a study by Susan Solomon, who testified before Congress on climate change about this time last year, on irreversible climate change. Even if we ceased emitting carbon dioxide today, Solomon and her coauthors show that we will be dealing with a thousand years ofContinue reading “Irreversible Climate Change and Drought in the Southwest”
One of the interesting reports coming out of the American Geophysical Union conference this year was on "abrupt" climate change. For a long time the Dust Bowl droughts of the l930's, which were indeed severe, were considered the worst the Southwest could expect. But now, based on tree-ring and pollen "proxy" studies, scientists can withContinue reading “Drought in the Southwest Can Last for Decades — or Centuries”
So says a new report — Weather and Climate Extremes in a Changing Climate — available at the U.S. Climate Change Science Program site. The title could be better, but it’s free. The report points to wetter storms (especially in the Midwest) and more severe droughts (especially in the Southwest). For someone living in SouthernContinue reading “The Wets Get Wetter, the Dries Get Drier”
The "new normal" in the Southwest is drought, about which we’ll be hearing plenty in the years and decades to come. Even some conservatives, such as the illuminating Rod Dreher, are writing about the fact that Dallas is expected soon to be a Dust Bowl, to the apparent anger and incredulity of most of hisContinue reading “Dueling Drought Stories”