By 2050, Southwest Forests Projected To See Worst Drought Conditions In At Least 1,000 Years

by Nick Sundt, via WWF

Scientists report in the journal Nature Climate Change that the drought-stress currently being experienced by forests in the Southwestern U.S. “is more severe than any event since the late 1500s megadrought” that “probably led to deaths of a large proportion of trees living at the time.”

They warn that climate projections indicate that “the mean forest drought-stress by the 2050s will exceed that of the most severe droughts in the past 1,000 years.”

In Temperature as a Potent Driver of Regional Forest Drought Stress and Tree Mortality (by A. Park Williams et al., Nature Climate Change, 30 September 2012), the authors say that the current severe drought event in the Southwest — which extends from 2000 to the present — is the fifth strongest since 1000 AD. They define the Southwest as including Arizona, New Mexico and the southern portions of Utah and Colorado. They attribute the current event both to natural variability and to rising atmospheric concentrations of greenhouse gases from human activity; and they associate it with “regional-scale declines in canopy greenness and tree survival, due in part to large bark-beetle outbreaks and increasingly large wildfires.”

A combination of declining precipitation during the cool season and rising temperatures during the warm season is likely by mid-century to be accompanied by increased forest decline. “If forest drought stress exceeds late 1500 levels, we expect that a lot of trees are going to be dying,” says the article’s lead research, A. Park Williams (Los Alamos National Laboratory), in a press release on Monday from the U.S. Geological Survey.

Consistent with many other recent studies, these findings provide compelling additional evidence of emerging global risks of amplified drought-induced tree mortality and extensive forest die-off as the planet warms,” said co-author Craig D. Allen, a research ecologist with the U.S. Geological Survey.

Nick Sundt is a climate change expert at the World Wildlife Fund. This piece was originally published at WWF and was reprinted with permission.

13 Responses to By 2050, Southwest Forests Projected To See Worst Drought Conditions In At Least 1,000 Years

  1. Chris says:

    My Firefox is reporting Think Progress as an attack site, thought you should know.

  2. Zimzone says:

    Mine as well, Chris.
    When you actually go to Google to see what the issue is, TP is given a clean bill of health.
    Right wing hacker, perhaps?
    We know how paranoid big oil is when it comes to the truth about climate change!

  3. Sime says:

    My version of Firefox is doing the same and was not doing so an hour ago – Firefox version is 10.0.7

  4. Zimzone says:

    I’ve got Firefox 13.0.1 and am getting it.

  5. Robert in New Orleans says:

    I am using IE8 and google is saying there is a danger to visiting this site, but does not show anything harmful on this site!?!? I got around the issue by typing the climate progress URL directly into the browser address line.

  6. Mike Roddy says:

    Let’s not forget logging. Intact forests store more water, and have much cooler microclimates. “Managed” forests and those subject to fire suppression are more vulnerable to serious damage and ecosystem alteration. Fire per se is not the problem.

    Not surprised that the oil companies are resorting to cyber warfare against this site. They are feeling the pressure, and it’s making them crazy.

  7. Mark E says:

    I’m getting the scare pages also. I use Firefox 15.0.1. Doing a google search for [climate progress] and then clicking the link produces

    this scare page.

    I then clicked the “safe browsing diagnostic page” link.

    Of the various explanations listed on that page, the one that appears most likely is “In some cases, third parties can add malicious code to legitimate sites, which would cause us to show the warning message.”

    Good luck resolving this issue.

    Mark E

  8. Jacob says:

    I’ll go out on a limb to say that like many other “projections”, we’ll reach this one far earlier than expected.

  9. Joan Savage says:

    From various sources, the decline and diaspora – if not complete disappearance – of the Anasazi included several centuries of recurrent droughts, with a last ditch attempt to survive drought by shifting from dry land farming to cliff dwellings.

    Short synopsis of dates:

    If I were a property owner in the Southwest, I’d be thinking hard about choices.

  10. Joe Romm says:

    problem is fixed.

  11. Joe Romm says:

    Been fixed, thx.

  12. Mark E says:

    WOW….. no megadrought after all!

    (sorry….. gotta take the laughs when they come)

  13. Merrelyn Emery says:

    You look pretty safe, ME