I am still trying to get a copy of the article in Science on which this is based, but the AZ Republic writes:
Western forests that withstood wildfire, insect attacks and drought are now withering under an even greater menace.
Heat.
Rising temperatures are wiping out trees faster than the forests can replace them, killing pines, firs, hemlocks and almost every other kind of tree at almost every elevation from northern Arizona to southwestern Canada.
Writing today in the journal Science, a team of 11 researchers says global warming is almost certainly the culprit behind a sharp spike in tree deaths over the past several decades. The higher death rates, which doubled in as few as 17 years in some areas, coincide with a regional increase in temperature and appear unrelated to other outside factors.
Perhaps this question is answered somewhere in the unreported details, but my first reaction was to want to ask “Dendroclimatologists like Michael Mann reconstruct history from tree rings based on the assumption that increasing temperatures correlates linearly and positively with tree growth and therefore tree ring width. Your study seems to indicate the correlation between tree growth and temperature is negative and probably non-linear. Can you reconcile these claims?’ Seriously, there may be an explanation (different kinds of trees?) but after plastering the hockey stick all over the media for 10 years, no one even thinks to ask?
Normally, I just ignore the flood of such academic work (every study nowadays has global warming in it — if these guys had just wanted to study the forest, they would have struggled for grant money, but make it about forest and global warming and boom, here’s your money). The reasons I picked it out was because I just love the quote below — I can’t tell you how often I see this in climate science-related work:
Scientists combed more than 50 years of data that included tree counts and conditions. The sharp rise in tree mortality was apparent quickly. Researchers then eliminated possible causes for the tree deaths, such as air pollution, fire suppression or overgrowth. They concluded the most likely culprit was heat.
Again, I need to see the actual study, but this would not be the first time a climate study said “well, we investigated every cause we could think of, and none of them seemed to fit, so it must be global warming.” It’s a weird way to conduct science, assuming Co2 and warming are the default cause for every complex natural process. No direct causal relationship is needed with warming, all that is required is to eliminate any other possible causes. This means that the less well we understand any complex system, the more likely we are to determine changes in the system are somehow anthropogenic.
Speaking of anthropogenic, I am fairly certain that the authors have not even considered the most likely anthropogenic cause, if the source of the forest loss is even man-made at all. From my reading of the literature, nearby land use changes (clearing forests for agriculture, urbanization, etc) have a much greater affect on local climates and particularly moisture patterns than does a general global warming trend. If you clear all the surrounding forest, it is likely that the piece that is left is not as healthy as it would have been in the midst of other forested land.
The article, probably because it is making an Arizona connection, makes a big deal about the role of a study forest near Flagstaff in the study. But if the globe is warming, the area around Norther Arizona has not really been participating. The nearest station to the forest is the USHCN station at the Grand Canyon, a pretty decent analog because it is nearby, rural, and forested as well. Here is the plot of temperatures from that station:
Its hard to tell from the article, but my guess is that there is actually a hidden logic leap embedded. Likely, their finding is that drought has stressed trees and reduced growth. They then rely on other studies to say that this drought is due to global warming, so then they can get to the grant-tastic finding that global warming is hurting the forest. But the “western drought caused mainly by anthropogenic warming” is not a well proven connection. Warming likely has some contribution to it, but the west has been through wet-dry cycles for tens of thousands of years, and has been through much worse and longer droughts long before the Clampetts started pumping black gold from the ground.
Warren,
Good post. I just posted on this subject about the same time you did. My local paper, The Oregonian (which is printed on dead trees I might add), reported on this subject this morning, and I thought your readers may be interested in my unscientific analysis of their reporting.
I found it ironic that they state a thirty year trend in warming caused more trees to die, which just happens to coincide with the last 30 or so year PDO warm period that I’m lead to believe has now ended. Perhaps this is worthy of some discussion here.
Here’s a link to my post…
http://gorelied.blogspot.com/2009/01/oregonian-1f-temperature-increase-in.html
Back in 1999, a friend of mine in Silicon Valley was running around trying to attract venture capital for a business startup. He could not attract an iota of interest from any of them. He soon found out that if his business plan did not contain “internet,” then no money would come his way. He noodled on it for a bit and came up with a business plan that incorporated “internet,” after which he had to beat back the VCs with a stick.
Flash forward to 2009. It is clear that if you want to attract money in the world of (pseudo-) science, you won’t get anywhere unless you have “global warming” in your thesis. I do believe that Warren is correct here: this “jarring” study’s conclusion was a foregone one. They would never have gotten their study off of the ground had their premise NOT had something to do with AGW.
If you’ve been wondering how to protect your assets from inflation in the coming years, it is obvious that the AGW phenomenon is where the Big Money is going to be during the reign of Premier Obama. Get in line now for your inflation-adjusted, plentiful, free money. You don’t need competence to earn it; only a preconceived outcome.
There is a huge Pulitzer out there for the journalist who bothers to check on this sort of bs at all and shows the obvious and accurate comparison between the quality of AGW hype and Wall Street financial management models.
Sensible people read a study, consider it, and then come to a conclusion. Idiots can apparently skip the first two.
“the assumption that increasing temperatures correlates linearly and positively with tree growth and therefore tree ring width” is one that is only made in your own bizarre fantasy world. Where do deniers get their crazed beliefs from? Would it not be wise to do some basic checking before exposing your horrific ignorance to the world?
RPJ,
Even less sensible is the process where, instead of gathering evidence, testing it and then publishing a conclusion based on the evidence, one does as AGW promoters do:
Reach a conclusion, manipulate data to support the conclusion and then pretend it is science.
But your trolldom is well established, so here we go again.
I hope that this is just an artifact of the scientist-to-journalist translation, but I can see a huge error in the methodology described in the article.
If all they’re doing is counting trees of each species, all they will be doing is measuring the process of succession, as the forest ages from an early mixed state with a high diversity of smaller trees to a later stage with fewer but larger trees with a lower variety of species. I’d also be interested in finding out if the researchers assumed that the forests were “pristine” at some past date, with no impact by Native American populations. These early populations seem to have been capable of large scale land use changes to make their local environments favor various easier to hunt species over others. The oldest growth stands in their study areas may be only one or two generations away from such practices prior to 1500.
Probably the best measurement of what they are trying to capture would be the rate of change of total cellulose mass per unit area in the study areas, as this would reach a peak at the point of maximum forest growth regardless of species diversity.
Here is the paper
http://www.werc.usgs.gov/seki/pdfs/Das%20et%20al%202008.pdf
I couldn’t find the direct reference to temperature in it, that probably wouldn’t have passed peer review without further substantiation.
The authors are being interviewed and throw in the global warming alarmist angle to get publicity
See the quotes in this article
http://www.mercurynews.com/breakingnews/ci_11532237
“”Rising temperatures have resulted in more of each year’s precipitation coming as rain rather than snow,” said Nathan Stephenson, a USGS ecologist and co-leader of the study. ”
This guy is really leaving the gist of the research behind.
At least teh lead author is less alarmist:
“If current trends continue, forests will become sparser over time,” van Mantgem said. “Simple projections of forest stand structure indicate that average tree age will eventually decrease by half, and this will potentially lead to decreasing average tree size.”
Sparser forests provide fewer places for animals to live, van Mantgem said, and also put trees at-risk for sudden die-off from catastrophic incidents such as fire, drought and bark beetle attack. In addition, because large trees absorb significant amounts of carbon dioxide, death of old-growth forests could further exacerbate climate change.”
It’s the press that fuels alarmism.
Hal
If the dieoff is due to drought, one possible cause is the current negative PDO in conjunction with a positive AMO.
http://oceanworld.tamu.edu/resources/oceanography-book/oceananddrought.html
“The most severe droughts occur when the PDO is in a negative phase, and the AMO is in a positive phase.
From McCabe (2004).
More than half (52%) of the space and time variance in multidecadal drought frequency over the conterminous United States is attributable to the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO). An additional 22% of the variance in drought frequency is related to a complex spatial pattern of positive and negative trends in drought occurrence possibly related to increasing Northern Hemisphere temperatures or some other unidirectional climate trend. Recent droughts with broad impacts over the conterminous U.S. (1996, 1999-2002) were associated with North Atlantic warming (positive AMO) and northeastern and tropical Pacific cooling (negative PDO). Much of the long-term predictability of drought frequency may reside in the multidecadal behavior of the North Atlantic Ocean. Should the current positive AMO (warm North Atlantic) conditions persist into the upcoming decade, we suggest two possible drought scenarios that resemble the continental-scale patterns of the 1930s (positive PDO) and 1950s (negative PDO) drought.
—McCabe (2004) “
If the tree loss is caused by drought, one possible cause is a negative PDO and a positive AMO.
“The most severe droughts occur when the PDO is in a negative phase, and the AMO is in a positive phase.
From McCabe (2004).
More than half (52%) of the space and time variance in multidecadal drought frequency over the conterminous United States is attributable to the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO). An additional 22% of the variance in drought frequency is related to a complex spatial pattern of positive and negative trends in drought occurrence possibly related to increasing Northern Hemisphere temperatures or some other unidirectional climate trend. Recent droughts with broad impacts over the conterminous U.S. (1996, 1999-2002) were associated with North Atlantic warming (positive AMO) and northeastern and tropical Pacific cooling (negative PDO). Much of the long-term predictability of drought frequency may reside in the multidecadal behavior of the North Atlantic Ocean. Should the current positive AMO (warm North Atlantic) conditions persist into the upcoming decade, we suggest two possible drought scenarios that resemble the continental-scale patterns of the 1930s (positive PDO) and 1950s (negative PDO) drought.
—McCabe (2004) ”
http://oceanworld.tamu.edu/resources/oceanography-book/oceananddrought.html
When I saw the first releases and articles about this study my curiosity set in. My initial reaction was to write a blog entry so I decided to investigate. The first thought was to look at the related states of the PDO and the AMO. I did a crude and rough comparison of the PDO and AMO states.
http://penoflight.com/climatebuzz/PDOAMOG1.jpg and then compared the combined states to the drought tendencies for those combinations.
Drought tendencies.
http://penoflight.com/climatebuzz/PDOAMO1.jpg
By that method I could not blame what they were saying on the PDO / AMO.
I checked the precipitation records for the US from 1976 to 2006 and there was a slight increase in precipitation nationally. Hence, if there study areas had drought they were anomalous to the national trend for the period.
Despite the divergence from the PDO / AMO drought tendencies I think it is most likely wrong to blame ‘Global Warming’. Not knowing the precise areas of study (yet) it is not possible to investigate further. Some have mentioned land-use, urbanization, etc. That is a possibility, depending on the exact areas of study the level of impact would change.
If I come to any solid conclusions I will be blogging them.
Another point to consider is this: To a certain extent, neighboring trees compete with eachother for sunlight. If some weather condition thins out a forest, conditions can potentially become more favorable for the remaining trees. So arguably there is negative feedback at work.
A system with feedbacks is much harder to analyze, understand, and predict.
My opinion only.
A possible cause of the drought is a switch from a positive to negative PDO.
“The most severe droughts occur when the PDO is in a negative phase, and the AMO is in a positive phase.
From McCabe (2004).
More than half (52%) of the space and time variance in multidecadal drought frequency over the conterminous United States is attributable to the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO). An additional 22% of the variance in drought frequency is related to a complex spatial pattern of positive and negative trends in drought occurrence possibly related to increasing Northern Hemisphere temperatures or some other unidirectional climate trend. Recent droughts with broad impacts over the conterminous U.S. (1996, 1999-2002) were associated with North Atlantic warming (positive AMO) and northeastern and tropical Pacific cooling (negative PDO). Much of the long-term predictability of drought frequency may reside in the multidecadal behavior of the North Atlantic Ocean. Should the current positive AMO (warm North Atlantic) conditions persist into the upcoming decade, we suggest two possible drought scenarios that resemble the continental-scale patterns of the 1930s (positive PDO) and 1950s (negative PDO) drought.
—McCabe (2004) “
I saw the article under discussion and soon after that saw this one:
http://www.paysonroundup.com/news/2009/jan/24/overgrowth_ponderosa_pines_endangers_arizona_water/
I understand that the two may not be mutually exclusive, but I did have a chuckle when I came across the Payson Roundup (in part b/c in my opinion the Republic has no credibility on this issue.)
Also, I heard Professor Covington (the primary source for the article I linked) speak about the health of western pine forests; his opinion is that the over-growth (trees too densely packed) is a problem that began about 100 years ago with the advent of fire-suppression and has taken that long to fully manifest itself. He also provided a couple of examples that were similar in that there was a 20 or 50 year lag between action and consequence.
With respect to the comment in re Native American’s effect: Prof. Covington’s view was that because indigenous people had been using fires in the forests for thousands of years, this (man-made fires) could be considered part of the “natural” state.
A. Statistical analysis is completely foreign to these people,
B. They have a documented socialist agenda, so
I don’t believe a goddamn thing “studies” like this say. They are written by amateurs for press releases to high school-level intellect journalists.
That’s it.
I saw the article under discussion and soon after that saw this one:
http://www.paysonroundup.com/news/2009/jan/24/overgrowth_ponderosa_pines_endangers_arizona_water/
I understand that the two may not be mutually exclusive, but I did have a chuckle when I came across the Payson Roundup (in part b/c in my opinion the Republic has no credibility on this issue.)
Also, I heard Professor Covington (the primary source for the article I linked) speak about the health of western pine forests; his opinion is that the over-growth (trees too densely packed) is a problem that began about 100 years ago with the advent of fire-suppression and has taken that long to fully manifest itself. He also provided a couple of examples that were similar in that there was a 20 or 50 year lag between action and consequence.
With respect to the comment in re Native American’s effect: Prof. Covington’s view was that because indigenous people had been using fires in the forests for thousands of years, this (man-made fires) could be considered part of the “natural” state.
(Pardon me if this is a double post — when I hit submit the first time it did not appear to work and nothing appeared after 30 minutes)
Alan,
You hit the nail on the head. Drought in the West is primairily caused by the formation of high pressure the moves in from the Northern Pacific and settles in and around the “Four-Corners” area of the Northwst Rockies. This high pressure cell has its genesis in the cold-moist areas south of Alaska, but as it builds into North America it does what all high pressure cells do -it drys the enviorment through subsidence. It is also responsible for the strong easterlies that over Southern California we call the Santa Anna winds. It is during La Nina events that the formation of the Four-Corners or Great Baisn High becomes most persistent.
Conversely, during El Nino events, strong zonal flow from the Pacific carries embedded short wave troughs that dump copious amounts of rain and snow across the Rockies. This provides plenty of moisture for undegrowth to spread along the windward side of the Western Rockies, and leads to massive forest fires during the dry seasons.
Winter fires are pretty normal during La Nina years, but Summer fires prevail suring El Nino years.
It would be inaccurate for scientists to blame drought on AGW as the most favorable atmospheric conditions for Western drought occur during prolonged La Nina years (also known as negative PDO events).
Warren:
Another study conducted by the University of Oregon reached a far different conclusion from that of the Science study:
You can read my post here:
http://herdgadfly.blogspot.com/2009/01/pine-trees-killed-by-beetles-are-shown.html
Hmmmmmmmmmm,
You deniers are just tools of our capitist society. Every one knows that corellation equals causation, Ipsdixit, it is proven.
I saw the article under discussion and soon after that saw this one:
http://www.paysonroundup.com/news/2009/jan/24/overgrowth_ponderosa_pines_endangers_arizona_water/
I understand that the two may not be mutually exclusive, but I did have a chuckle when I came across the Payson Roundup .
Also, I heard Professor Covington (the primary source for the article I linked) speak about the health of western pine forests; his opinion is that the over-growth (trees too densely packed) is a problem that began about 100 years ago with the advent of fire-suppression and has taken that long to fully manifest itself. He also provided a couple of examples that were similar in that there was a 20 or 50 year lag between action and consequence.
With respect to the comment in re Native American’s effect: Prof. Covington’s view was that because indigenous people had been using fires in the forests for thousands of years, this (man-made fires) could be considered part of the “natural” state.
Warren:
Another study conducted by the University of Oregon reached a far different conclusion:
“The massive insect epidemics that have plagued Pacific Northwest forests in recent years are mostly a reflection of poor forest health conditions, overcrowding, overuse of chemicals, fire suppression and introduction of monocultures or non-native species, a new report concludes.”
Read about it here:
http://www.watertalk.org/wawa/beetle/schowalter_study.html
“They have a documented socialist agenda”
Show us the documents then.
“We Eliminated Everything We Could Think Of, So It Has To Be Warming” is the same kind of thinking our ancient ancestors used when they came up with explanations for things they didn’t understand: “We Eliminated Everything We Could Think Of, So It Has To Be the Gods.” I thought we had left that type of thinking behind us long ago, at least in the scientific community, but I guess I was wrong.
RPJ,
First rule when losing is to dissemble, which you are getting a lot of practice at doing.
Hansen’s calls for the indictment of AGW skeptics is well documented.
But is their social agenda the point of this thread, or is the repeated use of highly questionable techniques to support pre-conceived results that do not conform with the historical record the real point?
I had to do a post on this paper too. These ‘scientists’ rationalizing global warming as a cause for what could be noise in their data because we couldn’t think of anything else was incredible.
You might be interested in the push by another less equal scientist who promotes global warming by power generation. This work comes to the same conclusions as AGW CO2 style, limit energy, ration and improve efficiency. But he claims the actual heat will warm the earth, well if he projects it out. This paper should never have made it past peer review.
http://noconsensus.wordpress.com/2009/01/26/another-kind-of-global-warming/
Wouldn’t trees dying from heat exhaustion at one elevation only thrive and prosper at a higher elevation?
Many of those tree populations live in mountain regions, spanning over large altitudinal ranges. A warming of 0.4 degrees per decade is equivalent to an altitudinal shift of 61 m at standard lapse rate, merely the height of some of those trees. They do use an elevation classification, in steps of 1000m. I wonder how a 61m equivalent shift can be detected in a 1000m range.
If warming were the cause, one would expect an elevation shift in the populations, none of that is reported.
Of course the word micrometeorology must be anathema here. It is all due to regional warming, even when slope and orientation within a single valley will have a stronger effect on temperature evapotranspiration and local hygric balance.
Even more interesting:
According to GISS maps, the Rocky Mountains forest area has had significant cooling since 1940.
http://data.giss.nasa.gov/cgi-bin/gistemp/do_nmap.py?year_last=2008&month_last=12&sat=4&sst=0&type=trends&mean_gen=12&year1=1940&year2=2008&base1=1940&base2=1980&radius=1200&pol=reg
Even more interesting:
According to GISS maps, there has been a significant decrease in temperatures in the the Rocky Mountain forest area since 1940.
http://data.giss.nasa.gov/cgi-bin/gistemp/do_nmap.py?year_last=2008&month_last=12&sat=4&sst=0&type=trends&mean_gen=12&year1=1940&year2=2008&base1=1940&base2=1980&radius=1200&pol=reg
The graph of grand canyon temperatures you gave is a complete fraud!
Why has it been hand-edited to end in 2005?
Why is the first temperature in 1900 and such almost 30 degrees above the rest?
Nah….
Indeed it is a complete fraud. Here is the actual data from USHCN. Looks a bit different, doesn’t it?
To be sure, there are plenty of examples where AGW believers / GW pessimists have manipulated data and published questionable statistical analysis. However, we have seen in politics that one side does not have a monopoly on sin. I have seen some skeptics / auditors (such as Watts, McIntyre, Christy) be very open with their sources and have made corrections when in error. Therefore, it tends to be easy for me to be more trusting of skeptic sources. However, Mr. Meyer’s Grand Canyon temperature data is suspect, and this is not the first time that he has posted questionable data. If he expects us to rely on the information in his posts, he needs to explain / correct / make it right. Independently, I did some research for the Rockey Mountain forest area on GISS — which of course has limited credibility but nevertheless has data going back into the earlier 1900s — and I see that the Rocky Mountain forest area has cooled noticeably since 1940 for the month of December. However, on an annual basis, the GISS adjustments show an upward trend in temperatures. (I have not been able to get the unadjusted option to work on the GISS website.)
You all are scientists and scientific thinkers, and I’m just a knee-jerk skeptic, but the very premise of this study made me laugh out loud. We are to believe that all manner of tree species thrive at one average annual temperature, but when that temperature is raised by 1 degree they die? These are trees that survive and thrive with annual variation in temperatures of 100 degrees?
That’s one of the stupidest things I have ever heard. God bless them if they can get people to believe that.
RPJ, you are comparing apples and oranges with that USHCN graph. That is the Monthly UHI Adjusted data. Warren is using the unadjusted Annual Mean data. Different fruit result in different images. You cannot get the annual mean data done as a chart on the USHCN website, best you can get is a CSV file from them. You can then convert that into a chart as Warren has done.
Flanagan, the chart is not a fraud as the USHCN data runs from 1903 to 2006. That is what Warren shows in the chart he generated and displayed for us. Do a little research before accusing someone. It is almost grounds for a libel suit in this instance.
Not so, Keith. My link was to a graph of annual means, which it is perfectly possible to get from the USHCN web site. UHI-adjusted, according to the heading, it is true, but the Grand Canyon is not noted for being subject to major urbanisation, or even being inhabited, so this makes no difference. Here is the unadjusted data.
The provenance of the originally posted graph is as yet unknown.
RPJ. You do know that USHCN data is heavily modified before you get a chart like that. They admit it on this page and this one as well.
I checked around the USHCN site, and found a data set from 1996, and there have been changes to data from that set to the current. I graphed the various sets to show the differences. I even graphed the sets matching the years involved, and the variance in the data is visual apparent.
Any idea what might be happening here?
Oh, they ‘admit’ it do they? I love the way a denialist idiot can pretend that simple documentation is some kind of ‘admission’. You’re getting your pants in a twist over tiny differences in data sets compiles twelve years apart, and yet you happily accept at face value the fraudulent posting of a graph that claims that the average temperature in 1904 was 14F higher than it was in 1905. Your hatred of science and love of ideology couldn’t be clearer.