Dozens of news outlets today carried the alarming “news” that climate change is causing the worst drought in centuries in the Western United States. This is false.
Research shows droughts in the Western United States have been far more intense and prolonged historically than the one the West is currently experiencing.
The New York Times (NYT) version of the story is, titled “How bad is western drought? Worst in 12 centuries, study finds.”
NPR’s coverage of the research was titled, “Study finds western megadrought worst in 1200 years.”
Both dramatic headlines refer to a new paper in Nature Climate Change (NCC), titled: “Rapid intensification of the emerging southwestern North American megadrought in 2020–2021.” Lead author Park Williams describes himself as a “bioclimatologist.”
The paper performs tree-ring analysis (of roof beams) from Southwestern archeology sites dating back to 800 A.D., with Chaco Canyon being one of the sites used for data.
According to the paper, data were spliced together with living tree-ring cores to form a complete SW US regional wet/normal/dry picture spanning about 1,200 years.
It is well established that coniferous trees grow better annually in wet conditions, yielding wider rings rather than dry conditions that give narrower rings, so as far as Williams’s analysis goes, the basis of the science is sound concerning historical representations of precipitation.
The tree-ring data tells a story of five major Southwestern US droughts since 800 AD. The claim is that the worst is at present; the next worst was a period that lasted 23 years in the late 1500s.
To a reasonable person, this should mean these periodic western droughts have little to do with climate change.
However, there is some trickery afoot. Williams has redefined megadrought and ignored available data to support his assertion that humans are causing a megadrought.
As Dr. John Christy of the University of Alabama in Huntsville explained in an email to me:
These guys redefined a megadrought down to 22 years so it was optimized to fit the most recent 22 years. Had they used 30+ years, they don’t have a result.
The alpine lakes of the Sierras are fine now, but during the real megadroughts, these lakes dried up so that forests could grow in the lake beds.
The use of models is inadmissible because they fail in producing natural variability which was the cause of the previous megadroughts.
Further, this NCC paper isn’t anything new. Climate Realism discussed similar claims in the post, “Claims of Southwest USA ‘Megadrought’ Are All Wet.”
That story used a graph (Figure 1 below) from another tree-ring study:
Figure 1 above uses data from the 2007 E.R.Cook et al. study showing severe droughts lasting as long as 200 years going back to 1200 years ago.
Meanwhile, at the far right, the drought we’ve experienced in the 21st century is evident and minuscule by comparison.
Williams conveniently forgot to mention those droughts. Maybe he should look at what the Los Angeles Times had to say about it in 1994:
Williams told NPR that the present megadrought is about one-fifth attributable to “climate change.” Note the NPR subtitle: “Human-Caused Climate Change Contributing.”
“Researcher Williams said roughly one-fifth of the current megadrought can be attributed to human-caused climate change. Greenhouse gas emissions are warming the world, speeding evaporation and disrupting weather patterns,” writes NPR.
How did Williams arrive at that conclusion? According to Williams’s analysis, present trees show about 20x greater drought severity than in the late 1500s.
By his reasoning, the difference MUST be completely “climate change”-related rather than natural variability. NYT says so. NCC says so. A bioclimatologist says so.
Williams closed the NPR interview with this gem;
“We cannot let ourselves get tricked by a few wet years into giving up on the progress we’ve been making.”
By “we”, he must mean the USA. It surely isn’t India and China who aren’t reducing CO2 emissions at all. See Figure 2.
Reality check: There have been droughts in the West as long as two hundred years, Mauna Loa’s Keeling curve shows no CO2 progress whatsoever, and Williams’s regional research shows normal and wet years will return; but apparently, all these facts are irrelevant to Williams’s viewpoint of “giving up on the progress” if we don’t immediately kowtow to the green agenda of reducing our energy use.
Read more at Climate Realism
NPR.Nazi Public Radio their still financing this leftists Propaganda who like the rest of the M.S. Media are Propagandists for the left
We had an article in today’s left-wing rag called the Denver Post. Must have used the same article that appeared in the NY Times. But as pointed out in this column real(tm) megadroughts can last two centuries, not two decades.