Climate and Drought

Two items in ClimateWire today.

Surge of blazes linked to climate — study

Higher temperatures spawned by climate change played a “decisive” role in spawning extreme wildfires in California, a new study said.

AUSTRALIA: Mega-drought of 1903 offers grim climate warning

Past studies by the science agency predicted that rising temperatures could afflict Australia with warmer summers and winters and more intense drought. Now, a new study that zeros in on the “mega-drought” from 1895 to 1903 suggests that “an increase in such events could be devastating for global biodiversity.”

8 thoughts on “Climate and Drought”

  1. Thanks 4 posting these Steve —

    And the USFS is doing what to manage forests to sequester carbon? NF’s in PNW Region 6 have some of the highest potential for carbon storage on earth!
    And what are they doing to accurately evaluate the carbon releases and potential climate impacts in project level NEPA analyses?
    Here on Mt. Hood NF the westside ID team is NOT doing a quantitative carbon analysis in NEPA. Just rolling merrily along as if climate change is not an issue…
    We can talk all we want about how climate change may affect forests but until we seriously grapple with the climate impacts of proposed timber sales, mega parking lot expansions (recent large new parking lot @ Mount Hood Meadows Ski Area) and other projects we are LITERALLY just blowing smoke!
    Heads in the sand approach may be fine with Trump but frankly, I expect better of the USFS.

    • Quantitative carbon analysis is not done on a project by project basis for the Forest Service for forest management projects. It is analyzed on a forest level and there is baseline data available at that level. So, just because they don’t look at that on a project does not necessarily mean that they aren’t concerned about climate change.

      • I’m afraid I don’t follow this. If the information is available at the forest level, what is the point unless it is to be used in project decision-making? This sounds like they are “concerned” but don’t have any intention of, or any mechanism for, doing anything about it. Maybe that mechanism is forest planning, and if so I look forward to seeing how it is used.

        Unfortunately, there’s still a NEPA problem: there is new information about the effects of the existing Forest management program, and the Forest owes the public a reasoned explanation of how that is being used in making its decisions.

    • Actually it is being funded and it is being implemented. PSW scientists will soon be publishing some work on that related to bark beetles and tree density – and they have good data to show that the density threshold for bark beetle areas should be lowered more than it currently is. And there are universities working on site-specific stand density models that incorporate climate, soils, and a host of other factors, and densities will probably be much lower on some sites. Insects are pretty good at showing us where we “mess up” when it comes to overly dense stands – especially during and after a drought…

  2. Here’s the Plain English abstract to the first study:
    “Since the early 1970s, California’s annual wildfire extent increased five-fold, punctuated by extremely large and destructive wildfires in 2017 and 2018. This trend was mainly due to an eight-fold increase in summertime forest-fire area and was very likely driven by drying of fuels promoted by human-induced warming. Warming effects were also apparent in the fall by enhancing the odds that fuels are dry when strong fall wind events occur. The ability of dry fuels to promote large fires is non-linear, which has allowed warming to become increasingly impactful. Human-caused warming has already significantly enhanced wildfire activity in California, particularly in the forests of the Sierra Nevada and North Coast, and will likely continue to do so in the coming decades.”
    The fact that large fires have increased may be due to a long term impact of fire suppression leading to more fuel onsite, which more readily dries out, as Larry says. The other part of the story that seems to be missing is fire suppression. It’s as if “climate change” goes directly to “drier fuels” which goes directly to “larger acreages of forest fires” without the intervening variables of “past fire suppression” and “how suppression currently works to reduce acreage of forest fires.”.

    • But what about a longer time period than since the 1970s? Is 4 or 5 decades enough to determine drought trends?

      This text is from a National Climatic Data Center web page entitled, “North American Drought: A Paleo Perspective.”

      “When records of drought for the last two millennia are examined, the major 20th century droughts appear to be relatively mild in comparison with other droughts that occurred within this time frame.”

      The link I have no longer works, but I captured a screen shot of the page several years ago.


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