From Brigham Young University:
Tree rings reveal nightmare droughts in the West
If you think the 1930s drought that caused The Dust Bowl was rough, new research looking at tree rings in the Rocky Mountains has news for you: Things can get much worse in the West.
In fact the worst drought of this century barely makes the top 10 of a study that extended Utah’s climate record back to the year 1429.
With sandpaper and microscopes, Brigham Young University professor Matthew Bekker analyzed rings from drought-sensitive tree species. He found several types of scenarios that could make life uncomfortable in what is now the nation’s third-fastest-growing state:
– Long droughts: The year 1703 kicked off 16 years in a row with below average stream flow.
– Intense droughts: The Weber River flowed at just 13 percent of normal in 1580 and dropped below 20 percent in three other periods.
– Consecutive worst-case scenarios: The most severe drought in the record began in 1492, and four of the five worst droughts all happened during Christopher Columbus’ lifetime.
“We’re conservatively estimating the severity of these droughts that hit before the modern record, and we still see some that are kind of scary if they were to happen again,” said Bekker, a geography professor at BYU. “We would really have to change the way we do things here.”
Modern climate and stream flow records only go back about 100 years in this part of the country, so scientists like Bekker turn to Mother Nature’s own record-keeping to see the bigger picture. For this study, the BYU geographer took sample cores from Douglas fir and pinyon pine trees. The thickness of annual growth rings for these species is especially sensitive to water supply.
Using samples from both living and dead trees in the Weber River basin, the researchers built a tree-ring chronology that extends back 585 years into Utah’s natural history. Modern stream flow measurements helped them calibrate the correlation between ring thickness and drought severity.
As Bekker and his co-authors report in the Journal of the American Water Resources Association, the west’s climate usually fluctuates far more than it did in the 1900s. The five previous centuries each saw more years of extremely dry and extremely wet climate conditions.
“We’re trying to work with water managers to show the different flavors of droughts this region has had,” said Bekker. “These are scenarios you need to build into your models to know how to plan for the future.”
Bekker collaborated with researchers from the U.S. Forest Service, Columbia University and Utah State University. The team is currently working on a climate reconstruction based on tree rings that date back more than 1,000 years.
ffohnad says:
May 2, 2014 at 11:32 am
In the early 1800′s the Great Plains were often referred to as the Great American Desert by cartographers and travelers alike. By the time large scale emigration started, climate had moved from the LIA into a bit wetter mode. There are many observations from early settlers that spoke of sufficient rain and the Term GAD disappeared from maps and minds.
Best
Doug
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But the settlers thought the change in climate was due to their agriculture and planting trees.
Hence, “Rain follows the plough” and Arbor Day. It seems mankind is perpetually fooling themselves into thinking they have much more influence over climate than they do. Heh heh.
These studies are only valid if the tree can be used for hockey sticks. It has to be able to flex and often blended with other wood for a composite of whatever feature the player wishes.
So how did the seagull count fluctuate, when these mega missing moisture malaises occurred ?? This could be significant for the future survival of Brigham Young, as a viable and livable research institution.
Why does my computer keep telling me that WUWT doesn’t have a legitimate “site certificate”, and windows update keeps on expunging it from my favorites list ?? Leave my “stuff” alone !!
Tim Ball says “None of this is new and no I am not tired of saying it, although I imagine some are tired of hearing it. It illustrates again how much the IPCC set back climatology.”
Absolutely. The focus on CO2 has misdirected our attention from the more powerfull natural causes of drought, The literature is chock full of similar studies for anyone who cares to seek the truth.
Tree stumps submerged beneath Lake Tahoe speak of unimaginable drought during colder times in an era when the atmosphere held 30% less CO2. Tree-ring studies reveal that droughts equal to the 1930s Dust Bowl and 1950s have occurred once or twice every century during the past 300–400 years, and a sustained mega-drought (a period of more frequent droughts lasting several decades) happens once every 500 years.
Central Africa suffered extreme droughts during the Little Ice Age. The effects of Little Ice Age mega-droughts also caused the collapse of the city of Angkor in Cambodia, and the Khmer empire, and coincided with the disintegration of nearly all of the major regional kingdoms of southeast Asia. The Great Victorian Drought during the cool 1870s resulted in horrendous famine in southeast Asia and caused the death of tens of millions of people, prompting widespread rebellions against the colonial French and British.
In North America, severe droughts lasting decades were centered around 1000 AD, 1500 AD, and 1800 AD. Reconstructions using lake and stream deposits as well as tree rings revealed a series of mega-droughts each lasting 20–40 years over a 400-year period. Reconstructions of California’s Sacramento River during the past 1000 years show the period beginning around 1350 AD was the driest 50-year period and the period beginning around 1140 AD was the driest 20-year period. The greatest frequency of extreme low river flow for the Colorado River occurred in the 19th century with “extreme event years in the 1840s and 1850s.”
More recently, studies around Glacier National Park (GNP) indicate the late 1800s suffered a series of droughts lasting more than 10 years, with the single most severe dry period occurring from 1917–41. That drought caused GNP’s immense Sperry Glacier to lose 60% of its mass between 1900 and 1950. All those severe droughts have nothing to do with rising CO2 or increased evaporation. They are better accounted for by changes in the El Niño cycles and the position of the Hadley Cell
read
Benson, L., et al. (2003) Influence of the Pacific Decadal Oscillation on the climate of the Sierra Nevada, California and Nevada. Quaternary Research, vol. 59, p. 151–159
Benson, L., et al., (2002) Holocene multidecadal and multicentennial droughts affecting Northern California and Nevada. Quaternary Science Reviews, vol. 21, p. 659–682.
Woodhouse, C., and Overpeck, J. (1998) 2000 Years of Drought Variability in the Central United States. Bulletin of the American Meteorological Society, vol. 79, p. 2693-2714
Russell,J.M., et al., (2007) Little Ice Age drought in equatorial Africa: Intertropical Convergence Zone migrations and El Niño–Southern Oscillation variability. Geology, vol. 35. p. 21–24
Buckley, B, et al., (2010) Climate as a contributing factor in the demise of Angkor, Cambodia. PNAS, vol. 107, p. 6748-6752
Sinha, A., et al., (2010) A global context for megadroughts in monsoon Asia during the past millennium. Quaternary Science Reviews, 1-16.
Mensig, S., et al., (2004) A Holocene pollen record of persistent droughts from Pyramid Lake, Nevada, USA. Quaternary Research, vol. 62. P. 29– 38.
Cook, E., et al., (2004) Long-Term Aridity Changes in the Western United States. Science 306, 1015-1018.
Cook, E., et al., (2010) Asian Monsoon Failure and Megadrought During the Last Millennium. Science, vol. 328, p. 486-489
Woodhouse, C. and Lukas, J. (2006) Multi-century tree-ring reconstructions of Colorado streamflow for water resource planning. Climatic Change, vol. 78, p. 293-315.
Pederson,G., et al., (2006) Long-Duration Drought Variability and Impacts on Ecosystem Services: A Case Study from Glacier National Park, Montana. . Earth Interactions, vol. 10, p.1 28
wws says:
May 2, 2014 at 11:43 am
It’s not nice to stop appeasing the storm gods with child sacrifices!
Now the Green Shirt druids have managed to remove their human sacrifice rituals from plain public sight. Also animals, of course, in the case of the windmill & solar panel sacrificial altars. And the odd light plane passengers & pilots.
Others have made the point about tree-rings being used for precipitation and for temperature, but I would like to pursue it more formally. Unfortunately, this particular paper is pay-walled so I can’t check it further. My questions are:
What feature or features of tree-rings is used to determine precipitation?
What feature or features of tree-rings is used to determine temperature?
The answers to these questions should presumably give a reasonable idea of whether tree-rings can legitimately be used for both.
I am glad too see others posting about North American droughts. I have heard tell from my native friends that there was a terrible drought in the south east region USA during the first half of the 16th century, they called it “The Great Starving Time” ….. It was long and devastating. I have heard stories from my native friends out west about a terrible climate changing event due to volcanoes popping off in the Four Corners area of what is today the South West USA. Said change was the rain stopped. For decades. These stories should serve to teach our world civilization that weather and climate can be nice or nasty and remaining sober and adaptive is a sound strategy for survival.
I have a problem with tree ring data. The obvious one, is that tree rings can be effected by numerous elements with the person(s) using the tree rings for their study doing the interpretation.
We all know that temperature and rainfall are factors which are hard to separate out(a cold/short growing season for instance could look like a drought) but in many cases, CO2 levels are even more important.
CO2 levels hundreds of years ago, during these severe droughts were very deficient at well under 300 ppm vs today’s less deficient 400 ppm. At these lower levels of CO2, small changes in CO2 have an even bigger impact in plant response. Woody stemmed plants/trees are effected most.
In the last decade, most scientists have underestimated these effects occurring right under their noses, so it’s hard to imagine that they are accurately estimating the effect of much lower CO2 levels on plants/trees response that lived hundreds of years ago.
We know that the increase in CO2 in the last few decades is even causing deserts to green up.
http://www.sciencedaily.com/releases/2013/07/130708103521.htm
Plants under drought stress are most effected (positively by more CO2) (negatively by lower CO2)
If I were comparing tree rings from the century prior to 1914, to those from the century after 1914, the older trees, growing with much less atmospheric fertilization should appear to have been subjected to more adverse conditions.
Droughts of equal intensity in 2014 and 1814, will clearly show up as more severe in trees from 1814 because they were not afforded the adaptation benefits of the 400 ppm CO2 levels in the atmosphere that humans have blessed them with.
Another related point that is a factor in slightly decreasing intensities of droughts since carbon dioxide have increased. This has not only caused massive increases in our planets vegetative health and plant growth and drought tolerance of plants but also increased evapotranpiration a great deal. As a result, there has been an increase in, especially, lower level atmospheric water vapor.
I note this as a negative feedback with lower lifting condensation levels for clouds (increase in low clouds and cloud height) as well as increasing precipitation.
With lower CO2 levels in the past, the reverse would be true, meaning droughts would be more likely.
As somebody forecasting weather in the US Cornbelt for over 30 years, I can tell you about the micro climate that sets up every year after the densely packed rows of corn are developed and adding 5+ degrees to dew points (at certain times) over an area the size of more than half a dozen states at times.
This does increase night time lows and the heat index but decreases day time readings, moisture stress and increases precip and soil moisture which causes additional contributions to future evapotranspiration, setting up a bit of a micro climate that is more beneficial to growing crops than before.
https://www2.ucar.edu/atmosnews/opinion/4997/corn-and-climate-sweaty-topic
Only Native Tribal legends capture the reality of worst case droughts. The White Man has not yet experienced the worst the Western US can offer.
Here are some peer reviewed abstracts showing US droughts and MEGA-DROUGHTS during the Holocene. It’s worse than you thought! And we must act now! Cheers.
But droughts are getting worse than we thought! We must, for the sake of the little grandchildren, act now! Yeah, of course we must.
Letter To Nature – 11 September 2012
Justin Sheffield et al
Little change in global drought over the past 60 years
…….Previous assessments of historic changes in drought over the late twentieth and early twenty-first centuries indicate that this may already be happening globally. In particular, calculations of the Palmer Drought Severity Index (PDSI) show a decrease in moisture globally since the 1970s with a commensurate increase in the area in drought that is attributed, in part, to global warming4, 5……..Here we show that the previously reported increase in global drought is overestimated because the PDSI uses a simplified model of potential evaporation7 that responds only to changes in temperature and thus responds incorrectly to global warming in recent decades. More realistic calculations, based on the underlying physical principles8 that take into account changes in available energy, humidity and wind speed, suggest that there has been little change in drought over the past 60 years. The results have implications for how we interpret the impact of global warming on the hydrological cycle and its extremes, and may help to explain why palaeoclimate drought reconstructions based on tree-ring data diverge from the PDSI-based drought record in recent years9, 10.
http://www.nature.com/nature/journal/v491/n7424/full/nature11575.html
You American’s should count yourselves lucky today you don’t live in the Little Ice Age.
It’s worse than we thought and it’s all man’s fault. We must act against climate change and the causes of climate change. Or is that global warming during the Little Ice Age? Of course and everything is entirely consistent with something or other.
I hear parts of Europe could get more droughts and floods. I suspect it’s part of that global weirding thingey.
Mike M
You say that plants suffer more under drought especially with a higher C O 2 level. I strongly disagree and ask for research positing this opinion. I have personally done studies and I believe the majority of research supports the fact the with higher CO 2 levels plants become more drought resistant. I would be interested in your sources.
After re-read. Nevermind
Tree rings only responds to temperature, just ask Mann. To infer other than temperature out of that is heresy. You all know that draught is because of cold, so when the rings are narrow, it is caused by cold. How complicated could it be?
By the way, global warming (climate change) also makes some places dryer, but it takes a climate scientist to deduce the prober connection.
I might be a lttle biased, but i find it amazing how any change is consistent with AGW.
Could they just tell which change would not be consistent with the AGW/CGW/CCC (catastrofic climate change).
ffohnad says:
“Mike M
You say that plants suffer more under drought especially with a higher C O 2 level. I strongly disagree and ask for research positing this opinion. I have personally done studies and I believe the majority of research supports the fact the with higher CO 2 levels plants become more drought resistant. I would be interested in your sources”
What are you looking at?
Here is what I stated:
“We know that the increase in CO2 in the last few decades is even causing deserts to green up.
http://www.sciencedaily.com/releases/2013/07/130708103521.htm
Plants under drought stress are most effected (positively by more CO2) (negatively by lower CO2)
If I were comparing tree rings from the century prior to 1914, to those from the century after 1914, the older trees, growing with much less atmospheric fertilization should appear to have been subjected to more adverse conditions.
Droughts of equal intensity in 2014 and 1814, will clearly show up as more severe in trees from 1814 because they were not afforded the adaptation benefits of the 400 ppm CO2 levels in the atmosphere that humans have blessed them with.”
I do have one correction to make in my previous statement:
“I note this as a negative feedback with lower lifting condensation levels for clouds (increase in low clouds and cloud height) as well as increasing precipitation.”
That should be an increase in low clouds and DECREASE in cloud height.
Tim Ball says: May 2, 2014 at 10:46 am
“None of this is new and no I am not tired of saying it, although I imagine some are tired of hearing it. It illustrates again how much the IPCC set back climatology.”
It’s not new in the IPCC either. The AR4 said, seven years ago:
Big droughts particularly around the LIA cold period!! This drought business is a cooling scenario it would seem. The Sahel greened following the 1990s hot period. Don’t the CAGW folks have this backwards.
george e. conant says:
May 2, 2014 at 2:13 pm
The worst was earlier. An entire civilization was effectively wiped out. The classical Mound Builders of the Mississippian Culture were devastated by the LIA that also destroyed the Greenland Norse. The great ceremonial center of Cahokia thrived for centuries during the Medieval Warm Period, which according to CACA adherents wasn’t global, if it existed at all, but was gone by AD 1400.
http://en.wikipedia.org/wiki/Cahokia
Natural climate change with a vengeance. Turn up the heat!
I am just plain glad to see tree ring studies used properly, i.e. not for temperature reconstruction.
Tim Ball says:
May 2, 2014 at 10:46 am
None of this is new and no I am not tired of saying it, although I imagine some are tired of hearing it. It illustrates again how much the IPCC set back climatology.
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Keep saying it Dr Ball. Every generation has its fraudsters who want to take credit for inventing the wheel. The role of the previous generation is to keep them in line.
When you go back and read some of the old research, the meticulous records, you realizable how shoddy a lot of the modern work is in comparison. Publish or perish creates quantity not quality.
It’s not new in the IPCC either. The AR4 said, seven years ago:
=============
“But the records (AR4 Section 6.6.5.5 ) were on display …”
“On display? I eventually had to go down to the cellar to find them.”
“That’s the display department.”
“With a flashlight.”
“Ah, well the lights had probably gone.”
“So had the stairs.”
“But look, you found the section didn’t you?”
“Yes,” said Arthur, “yes I did. It was on display in the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door saying ‘Beware of the Leopard’.”
Drought conditions mean fewer clouds from lack of humidity, which means not only hot summer days, but colder summer nights, and extremely cold and dry winters. If treering growth indicates that water levels were low from lack of rain and snow pack, you can bet some cold temperature records were broken.
Svend Ferdinandsen says:
May 2, 2014 at 4:25 pm
I might be a lttle biased, but i find it amazing how any change is consistent with AGW.
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A question for Nick Stokes and climate scientists everywhere. What would it take to show that AGW was wrong? What set of events would have to happen for you to accept that AGW was an incorrect explanation for observed climate change?