Claim: The Current US Megadrought is Being Made Worse by Climate Change

Guest essay by Eric Worrall

According to New Scientist, anthropogenic CO2 is making the current drought harsher. But they admit an even worse drought occurred in the 16th century.

US megadrought is being made more intense by effects of climate change

ENVIRONMENT 16 April 2020
By  Adam Vaughan

Climate change caused by humans transformed an otherwise moderate drought in the US and Mexico into one of the driest periods in more than a millennium.

While the area was known to have suffered past extreme droughts due to natural cycles such as the La Niña climate phenomenon, A. Park Williams at Columbia University, New York, and his colleagues, have now revealed that potentially almost half of the current episode’s severity was down to human-caused global warming. The event was second in intensity only to a megadrought at the end of the 16th century.

Williams’s team worked out the region’s soil moisture, a measure of drought, for the past 1200 years. Calculating figures for the past century was straightforward, using temperature, rainfall and other weather records to construct soil moisture. To go further back in time, they used data from more than 1500 tree-ring records. These give an indication of how rapidly trees grew in a given year, which is based in part on how much water there was in the soil at the time.

“Even without climate change, we still would have had a drought,” says Williams. “But this drought would have been no big deal without climate change.”

Read more:

The abstract of the study;

Large contribution from anthropogenic warming to an emerging North American megadrought

A. Park Williams1,*, Edward R. Cook1, Jason E. Smerdon1, Benjamin I. Cook1,2, John T. Abatzoglou3,4, Kasey Bolles1, Seung H. Baek1,5, Andrew M. Badger6,7,8, Ben Livneh6,9

See all authors and affiliationsScience  17 Apr 2020:
Vol. 368, Issue 6488, pp. 314-318
DOI: 10.1126/science.aaz9600

Severe and persistent 21st-century drought in southwestern North America (SWNA) motivates comparisons to medieval megadroughts and questions about the role of anthropogenic climate change. We use hydrological modeling and new 1200-year tree-ring reconstructions of summer soil moisture to demonstrate that the 2000–2018 SWNA drought was the second driest 19-year period since 800 CE, exceeded only by a late-1500s megadrought. The megadrought-like trajectory of 2000–2018 soil moisture was driven by natural variability superimposed on drying due to anthropogenic warming. Anthropogenic trends in temperature, relative humidity, and precipitation estimated from 31 climate models account for 47% (model interquartiles of 35 to 105%) of the 2000–2018 drought severity, pushing an otherwise moderate drought onto a trajectory comparable to the worst SWNA megadroughts since 800 CE.

Read more (paywalled):

Unfortunately the full study is paywalled. But as the study authors admit, a worse drought occurred in the late 1500s.

Acting on climate change by eliminating CO2 emissions won’t stop severe droughts from occurring. There weren’t many SUV’s being driven around in the 1500s. But eliminating CO2 would throw away affordable energy, which is our best tool for addressing droughts when they occur.

Affordable energy makes it possible to survive a drought and prosper, by making large scale pumping economically viable. If groundwater runs out, there are regions of the USA with water to spare, which are currently experiencing an abundance of water.

If the situation deteriorates, if the entire USA starts to experience severe drought, affordable fossil fuel energy could be used to power monster desalination plants to make up the shortfall.

0 0 votes
Article Rating
Newest Most Voted
Inline Feedbacks
View all comments
April 18, 2020 6:11 am

“Current Mega-drought” where?
comment image

Reply to  JCalvertN(UK)
April 18, 2020 7:16 am

A mega-intelligence drought is worse than ever, especially in Boulder where cool temps and precipitation for almost the past decade are quite the opposite of what is claimed. Boulder just set the seasonal record in terms of precipitation going back over a hundred years and just this past week, 4 low temperature records have been set so far.

With regard to paywalls, Sci-Hub makes knowledge free and works on the science article. Another route for free knowledge is to log into many college and university networks.

Walter Sobchak
Reply to  JCalvertN(UK)
April 18, 2020 8:09 am

Where? Around Washington DC. It is not really a shortage of water, it is a shortage of good sense and clear thinking.

Bill Powers
Reply to  Walter Sobchak
April 18, 2020 8:39 am

Washington DC is also know as “Hollywood for Ugly People” and everyone knows how stupid Hollywood People are. They jump on social media and demonstrate stupid daily.

Robert W. Turner
Reply to  JCalvertN(UK)
April 18, 2020 8:10 am

Maybe there is “potentially almost” a mega-drought. Or perhaps they are mega-dumb or in mega-need of funding.

Reply to  JCalvertN(UK)
April 19, 2020 12:57 am

The Palmer Index uses negative numbers to indicate drought. I can’t correlate that to your picture at all. Are the green areas drought or no drought?

Reply to  pls
April 19, 2020 5:34 pm

Try this then . . .comment image

April 18, 2020 6:15 am

Where is this mega drought (century+ long)?


Walt D.
Reply to  DocSiders
April 18, 2020 6:28 am

Inside the Virtual Reality goggles of a broken computer model.

Curious George
Reply to  DocSiders
April 18, 2020 7:40 am

Ice cores indicate that periods of low temperature correspond to “megadroughts” when spreading desert areas make the air more dusty.

April 18, 2020 6:15 am

Old Aussie bush saying which has been proven 100% correct since forever –
At the end of every drought there’s a good rain.

Dr. Bob
April 18, 2020 6:25 am

CO2 also makes plants more tolerant to drought, so why is that not included in the analysis to give it a more complete picture of the situation? I would guess so that the mime hold together and they don’t spread rumors that plants might just be adaptive enough to tolerate climate changes.

What will be very interesting is to see the impact or lack of impact of the current 30% drop in crude oil consumption on Mauna Loa CO2 measurements. This impromptu experiment will be telling.

Reply to  Dr. Bob
April 18, 2020 10:24 am

Dr. Bob, if manmade emissions dropped by 30% over several years then perhaps it could be teased from the noise. Consider that CO2 naturally varies on multiple time scales, and the annual contributions from burning fossil fuels is about 3-4% of the total.

Currently, annual increases in CO2 are about 2.5 ppm. But this is variable mainly depending on sea surface temps. From 1996 to 1997 it was 1.12 ppm. From 1997 to 1998, the increase was 2.97 ppm. From 1992 to 1993 it was 0.65 ppm and from 2015 to 2016 it was 3.41 ppm.

It ought to be obvious that mankind’s emissions do not vary to that degree, but assume that all of that average 2.5 ppm annual increase is manmade. A 30% drop would on average yield a 1.75 ppm increase instead. That kind of difference would be within normal variability.

But then NOAA’s use of significant figures would make a college freshman blush and this opens them up to all kinds of nonsense. I doubt that the experiment will be meaningful, but we shall see.

Dr. Bob
Reply to  Scissor
April 18, 2020 12:19 pm

That is the point of the experiment. That the variability is greater than the effect. This is why there is a test to the theory. If the data doesn’t support the theory, then the theory has to be modified or discarded. Thus the interest in the “impromptu” experiment.

Garland Lowe
Reply to  Dr. Bob
April 18, 2020 12:36 pm

If the data delivers the wrong conclusion, they will adjust the data or blame faulty equipment. This is the way they roll.

Reply to  Garland Lowe
April 18, 2020 5:45 pm

Respectfully Garland, I think you phrased that incorrectly. They already have the conclusion, but the second part of your sentence is correct.

Reply to  Dr. Bob
April 18, 2020 1:58 pm

If the data doesn’t support the theory, then the theory has to be modified or discarded.

Normally yes Dr. Bob, however, in this case, “Dr. Stahle’s research is funded by NOAA, NSF, NPS and the USGS and he has published in a variety of journals including, Science, Nature, Journal of Climate and Bulletin of the American Meteorological Society.”

Now, given Dr. Stahle is funded by government AND he has submitted papers which have been approved for journal publication by a review of his peers, don’t you think that satisfies any reasonable criteria for modern-day scientific truth?

As opposed to, e.g., the Heart[less] Institute, which, by their own admission, accepts NO government funding whatsoever, AND does not reveal their donors, which therefore necessarily allows us to immediately assume the worst don’t you agree?

For example, according to one internet posting I found from user, Tim Huelskamp (formerly “congressman” (h/t Jeff Alberts) Tim Huelskamp, R-KS) replaced Joe Bast as president of the org in or around the year 2017. What’s to die for in this posting is the FACT that Huelskamp’s top donor at the time while a congressman was Koch Industries! Certainly if Koch contributed to Tim Huelskamp, R-KS, then why wouldn’t they contribute to Tim Huelskamp, President, Heartland Institute? Why I ask you???

Now . . . you COULD claim that from the former that it does not follow the latter is true. But if I’m just your average AGW climate believalist communicator peddling AGW truth from (and anyone could assume that I am) what am I supposed to do with these facts?

What say you Dr. Bob? How am I wrong?

Dr. Bob
Reply to  sycomputing
April 19, 2020 7:49 am

The answer is always “Yes” when data doesn’t fit theory. Science is a Data Driven activity. Theories have to account for the data as it exists, not after it has been manipulated. Read the Feynman Lectures on this subject for a clear view of how to interpret data.
The rest of your response is not worth commenting on as just because a person accepts donations from an organization doesn’t always mean he is indebted to that organization in perpetuity.
Your comment about “Dr. Stahle” shows that you don’t understand much about how science works today. What if a new piece of data arrives that doesn’t fit Dr. Stahle’s conclusions in papers he published and had peer reviewed? What should happen is the premise of the paper should be questioned and revised as needed to fit the data.
However, in CAGW thought, walls are built up and data adjusted to fit the preconceived theory. That unfortunately leads to erroneous conclusions which in this case cost society enormous sums of money and effort that could have been spent on more worthy causes. Such as preparing for global health issues and not worrying about a degree or two in normal temperature variations.

Reply to  sycomputing
April 19, 2020 12:49 pm

Dr Bob:

Wow THANKS! I’ve never looked at my commentary in this way before now. You’re the absolute BEST, Dr. Bob!

I am forever in your debt!

Reply to  sycomputing
April 19, 2020 11:38 pm

Well I thought it was a jolly good question, I would say you are not. Bob’s scepticism seems to be conditional.

April 18, 2020 6:38 am

There are places that are experiencing a shortfall of water, for various reasons. The Pacific Ocean is currently experiencing an abundance of water.

The fact of the matter is, the Earth has more water than ever. Tiny bits of ice bombard the Earth every day, so the Earth is adding to it’s stock. Precious little has left the Earth. It’s expensive to send it up into orbit.

As a regular poster here (I’ve forgotten who, sorry) posts on occasion, “there is no shortage of water.” It’s a distribution problem and an economic problem. Current technologies can get water of any sort in any amount anywhere.

It’s all a matter of ability to pay or willingness to pay.

Eric Worrall brings this point up in the article by reminding any worrywarts that desalinization plants are already a thing. However, I don’t think any worrywarts are reading this article.

Reply to  H.R.
April 19, 2020 1:10 am

Actually, a lot of water has left the earth, thanks to the sun. UV splits water into hydrogen and oxygen. The light hydrogen floats to the top of the atmosphere and is stripped off by the solar wind.

Over its history, Earth has net lost 25% (more or less) of its original water. Mars has lost more.

Dave O.
April 18, 2020 6:38 am

We’re hoping for a drought. We’ve had to endure flooding for the past year, but since weather is cyclical, drought is probably not far away.

April 18, 2020 6:38 am

The alarmists twist themselves into pretzels trying to explain why the current warming isn’t just a natural rebound from the Little Ice Age.

The climate deniers are the ones denying natural variability.

David A
April 18, 2020 6:41 am

Seriously, what mega drought?

Walt D.
Reply to  David A
April 18, 2020 7:55 am

Where ready a Climate Science puff piece you need to replace mega with micro and catastrophic with microscopic.

April 18, 2020 6:55 am

I was going to ask what mega drought. It looks like several have beaten me to it already. Piles and piles of snow here the last several years. In fact a few inches of new snow yesterday morning.

Stuart Nachman
April 18, 2020 7:23 am

comment image
comment image

Judging by data from Boulder, CO and the reality in CA last year, you would not know it.

Steve Keohane
April 18, 2020 7:43 am

What drought? Snowpack in the west central Rockies is 116% of normal in spite of a ‘warm’ winter….

Steve Oregon
April 18, 2020 7:49 am

Peter Gleick and others wrote on how the 2015 drought in California showed signs of climate change.
That one year has been milked exhaustively by alarmists as what to expect “in a warming world”.
The fully saturating, inundating, reservoir filling, aqua fir filling deluge years that followed blew up their concocted visions of permanent drought.
Now it’s a bit dry this year so they’re all hoping for another opportunity to recycle their bleating gibberish.

I’ve followed the California AGW drought meme for years and found this in 2018.
In a nearby precip record , 1942-present , shows zero climate change.—Present-PDF?bidId=

This morning I found this stunning recognition at the conclusion of an extensive Future Sustainable Yield report for Paso Robles, California.
“The estimated future sustainable yield is similar to the estimated sustainable yield
for the historic base period. This similarity indicates that potential future changes in climate are
not projected to have a substantial impact on the amount of groundwater that can be sustainably
used compared to historical conditions.”

April 18, 2020 8:29 am

What drought? Build a damn pipeline, knock down a few dams and repair or replace the rest. Then get to work replacing crumbling water delivery systems and filtering the contaminates out.

Tom Abbott
April 18, 2020 8:31 am

From the article: “Anthropogenic trends in temperature, relative humidity, and precipitation estimated from 31 climate models account for 47% (model interquartiles of 35 to 105%) of the 2000–2018 drought severity, pushing an otherwise moderate drought onto a trajectory comparable to the worst SWNA megadroughts since 800 CE.”

There’s the problem right there: using climate models that don’t represent reality.

There is no evidence that CO2 is causing the atmosphere to be warmer than in the past, so claiming human-caused CO2 is the problem and is causing droughts is not based on the facts. The facts are it was just as warm in the recent past as it is today. More CO2 in the atmosphere has not caused it to be warmer than in the past.

I wonder where the Dust Bowl of the 1930’s figures into this mix. That was about as dry a period as we have had, and today is nothing like the 1930’s when it comes to heat and drought. Not even close.

Here in Oklahoma, in the middle of the Dust Bowl area, we had a severe drought around 2011, and then the rains came and we have been sitting pretty ever since. I fact, we had record rainfall last year, and it was looking like it was going to be a repeat this year but the focus seems to have drifted off to the east a little this year.

It’s not uncommon for this area to suffer a severe drought of a year or two length but the rains always come and make things better and none of this has anything to do with human-caused CO2.

To claim CO2 is causing the atmosphere to do something, you have to demonstrate that it is. This has not been demonstrated, so any studies based on this being an established fact, are building their house on a foundation of sand.

The biggest problem with all these studies is they assume something not in evidence. They assume someone else has already established that human-caused climate change is real, and they just start off from there, I suppose never thinking that if the basic premise is wrong, that probably makes the results of their study wrong.

It’s like assuming lead can be transformed into gold, because someone said so, and then making all sorts of assumptions about the future based on that. Start off wrong, and you are going to stay wrong.

Tim Gorman
Reply to  Tom Abbott
April 18, 2020 9:10 am

Do these climate scientists ever actually get out in the field and talk to people?

You would think that with a mega-drought we would be seeing ever decreasing grain harvests in the US. Yet exactly the opposite is occurring. There *is* a reason for that. If these study authors would take a trip around the US sometime and actually do some field research perhaps they might actually learn something about reality instead of model outputs being their total universe!

April 18, 2020 9:52 am

Media told me that there has been no snow or rain anywhere in the continental USA for the last 18 months and we all died of da terrible virus anyways so y’all just need to trust da gubbament to take care of you(re rotting carcass). Have a nice day.

April 18, 2020 10:11 am

“There weren’t many SUV’s being driven around in the 1500s”

So there were some !

Reply to  Petit_Barde
April 18, 2020 11:10 am

I don’t know about SUV’s, but there were De Sotos, Mustangs, Jaguars and Road Runners.

Kevin McNeill
April 18, 2020 10:46 am

The graph shown is on the positive side(wetter) not negative and the trend is to the positive, ergo, no drought!

Andy Pattullo
April 18, 2020 2:04 pm

So if the real world behaved like the climate models then nearly half of a mega drought which doesn’t exist in the real world would have been caused by anthropogenic climate change for which there is scarcely any evidence in the real world. We are to believe the climate models are the truth and objective reality is an illusion because everything the models predict is absent in the real world. Clearly our perceptions are flawed and the computers and their puppet masters are omnipotent.

April 18, 2020 2:12 pm

Is Ancient People’s End a Warning for the Future?

But sometime in the late 1200s, the Anasazi abandoned all of their pueblos. And for more than a hundred years, archaeologists have been perplexed about why.

Kuckelman thinks the reason was climate change. A major drought hit the area in the 1270s. Kuckelman says her research from one of the villages, Sand Canyon Pueblo, shows that the drought destroyed the people’s ability to grow corn to feed themselves and their turkey flocks. They were forced to revert to hunting and gathering.

Where were the SUVs and coal fired energy plants in the Southwest in the late 1200’s and the late 1500’s ?

It sounds like there is some type of phenomena that cause periodic droughts. Climate change loonies say these cahnges are permanent. Then why was there a worse drough in the 1500’s maybe back in the 1200’s. Have they used their super whizbang weather gizmos to look back farther ?

April 18, 2020 3:45 pm

“….But this drought would have been no big deal without climate change.”….saying the opposite would not align with next year’s funding request.

Michael Jankowski
Reply to  DMacKenzie
April 18, 2020 6:17 pm

It also would have been no big deal without the increase in water demands in the region over the past few hundred years. Or better water resources planning.

April 19, 2020 9:11 am

The Current US Megadrought


%d bloggers like this: