Sunday, December 20, 2009

Tree Rings, Peer Review, and Fox News

Yesterday I watched a Fox News special on climate change called, "Global Warming... or a lot of hot air?". It was unsurprisingly biased to: 1) Raise doubt about the science and question the motivations of the majority of scientists who believe climate change is a serious problem, 2) Downplay the likely consequences of global warming, and 3) Up-play fears of big government control, increased taxation, and social and economic consequences that might be associated with reducing greenhouse gas emissions. I'm sure someone else on some other blog will do a better job of countering the program, but I'll do a quickie version here.

1. The Fox special didn't get much into the basic science of what global warming is; why there is concern about increasing greenhouse gas concentrations, etc., probably because the basic science is relatively simple and compelling, and Fox's mission was not to educate but to sow confusion and doubt. So, Fox mainly gave the grandstand to climate skeptics and spin-doctors from conservative lobby groups like the Cato Institute. These "experts" nit-picked at various real and imagined errors in the mainstream science of global warming. In particular, they quote-mined the emails stolen from the University of East Anglia's Climate Research Unit (CRU) in order to imply that the scientists there (and by extension, all global warming scientists) were conspiring to fake results and supress dissent. The quote from the CRU scientists that Fox kept repeating was "hide the decline", which was taken out of context but originally had to do with interpreting past climate from tree rings.

An old-growth Douglass Fir, the author's favorite tree species.

Since thermometer-based records of temperature are rare before about 100 years ago, scientists use "proxies" like tree rings and isotope ratios from ice cores to infer what the temperature was in the past. The tree ring method works pretty well, i.e. it correlates closely with the other temperature proxies and with real thermometer measurements, but only until the mid 20th century, at which point tree rings appear to show declining temperatures while all the other indicators show increasing temperatures. The reason the tree-ring vs. real-temperature correlation breaks down during this century is because increasing CO2 in the atmosphere is changing the pattern of tree growth. Trees have to open up pores on their leaves to take in CO2 for photosynthesis. When their pores are opened up they lose water, which slows their growth. But with the increased CO2 in the atmosphere they don't have to keep their pores open as long to get enough CO2, so they don't lose as much water and their growth is less affected by drought. That gives the same effect on their rings as if the temperature was decreasing. The scientist who wrote "hide the decline" was talking about how, in one particular graph from an old report, he had substituted the REAL temperature data for the tree ring data starting in 1960 where the tree ring data got screwy. That made a better representation of the real situation, but the graph wasn't properly labeled to show he had done that, which was sloppy work.

The same scientist who made the tree ring graph also had some math errors in some of his other data, which were pointed out by a global warming skeptic named Steve McIntyre. Even though McIntyre is idealogically motivated to attack the science of global warming, and often distorts the facts to that end, the problems he found in that particular scientist's data were real, and were later corrected. But after that, the CRU scientists were resentful against McIntyre, and resistant to sharing their data with him or other skeptics. They didn't want to have some skeptical papers included in one of the International Panel on Climate Change reports, and they talked about wishing they could change the definition of "peer-reviewed papers" so they could be excluded.

(Peer-review is the system for making sure that sloppy, flawed, unconvincing, overly-speculative or biased reports don't get published in official science journals. When a scientist writes a research paper and sends it to a journal, the journal editor randomly picks a small panel of "peers" to check it for quality. The peers are other scientists who are knowledgeable in the subject but unaffiliated with the writer. Sometimes mistakes get past the reviewers, or good studies get unfairly rejected, but usually it works pretty well.)

What the Fox News special didn't explain was that the CRU had no ability to actually change the peer-review system, and that the skeptical papers in question WERE accepted by reviewers and included in the IPCC report. In summary, the stolen emails showed some sloppiness and snobby behavior among the scientists, but real no conspiracy or fraud, which is more than one can say about the conservative spin doctor "think tanks" that are funded by multi-billion dollar industries to debunk global warming however they can.

Another thing that was silly about the Fox News report was how they kept referring to the results of Fox viewer polls, as if the misinformed opinions and suspicions of their conservative American audience were actually a better indication of reality than the worldwide consensus among climate scientists. One of the polls that I found particularly galling regarded the motivations of scientists. Apparently the majority of Fox viewers think scientists don't honestly believe global warming is a serious danger, but are drumming up fear and sensationalism to in a cynical effort to grab money and power for themselves. As a scientist myself, I can tell you that that is ridiculous. Scientists are definitely not out for money, at least not more than is necessary to continue studying the things that we think are interesting and important. And, while we would like it if politicians and voters would pay more attention to our scientific findings and make more rational, informed decisions, we're not out to sieze personal power.

2. The Fox special downplayed the likely consequences of global climate change. They mainly did it by not mentioning the consequences at all- consequences which include everything from loss of coral reefs, to spread of diseases, to crop failure, drought, and starvation. They even said, citing a very low-end estimate of sea level rise, that it would be "no big deal". That's a very naive and cavalier attitude to have, given that even natural ups and downs in weather and climate have had huge effects on human societies in the past, and man-made climate change is predicted to be a lot bigger and worse than those. Think of the 1930s dust bowl in the American plains, or the 19th century cities and towns on coastal islands that are now under water or eroded away. A bunch of things like that happening all over the world would definitely be "a big deal".

3. The key part of the Fox special's "don't give a hoot" message was casting aspersions on efforts to prevent climate change. They set up a false dichotomy, like, "if you want to prevent global warming you must also want to trash the economy, give up your indivdual rights and freedoms, neglect more pressing social concerns like third world health care and literacy, and basically go back to the stone ages". It's not like that, though. The whole "choose the environment or choose the economy thing is bogus" because you can't have a stable economy without a stable environment. The free "ecosystem services" that are provided by nature, like consistent rainfall, fish stocks, crop pollination by insects, waste-absorption by wetlands, erosion control by forests, etc., are a huge part of the economy that will be extremely costly, if not impossible, to replace if they get messed up by global warming and other types of environmental change.

We're a lot like the Easter Island society where the economy was based on cutting down trees for fuel and building material. Their whole economy and society collapsed when they ran out of trees and they pretty much all died off because they didn't have any alternative. The Fox special said that it would be impossible for our own society to meet all its energy needs with alternative sources other than fossil fuel, but they totally neglected to consider CONSERVATION. If we use energy less wastefully then it will be much easier for alternative energy to make up the difference.

As for the giving up rights and freedoms, it doesn't have to be so, but some kinds of regulation are necessary to avoid "the tragedy of the commons". That's like, where lots of people are sharing a resource that will get ruined if it's overused, but since it benefits each individual user to use it as much as possible before the other guys do, they will end up overusing it anyway and all being screwed in the end... Unless they can come to an enforced agreement about sharing it equitably and using it moderately.

Regarding the argument that spending money to fight global warming won't make as much improvement to the world as spending money on, like, vaccinating and feeding orphans in Rwanda, that's true. But only in the short term. Because in the long term, if we don't do something about climate change, unsustainable population growth, etc., there will be a lot more people experiencing poverty and starvation and stuff. So we need to both address current sufferring AND prevent future sufferring.

Anyway, that's about all I have for now. Feel free to leave a comment if you agree or disagree or whatever. Thanks.


Mary said...

I think you did a great job of explaining this stuff -- yours is the first explanation I've seen of the tree-ring data and "declining" temperatures, so I'm glad to understand what that's all about. The public's lack of basic understanding of how science works has always been disturbing to me. I liked the way you explained about the peer-review process. That's definitely one of the things the average non-scientist just doesn't get.

am said...

James - I find your comments on the Fox News show to be more ideological than scientific ("Ugh", "Silly", etc.). I, too am a scientist and have been appalled that most laymen have been largely influenced by the Gore film "An Inconvenient Truth" which is pretty lose with that same "truth". Most are ideologically or emotionally moved to fear and panic and know nothing of the real science behind the "movement". The major propenants of the AGW movement hide in their towers and refuse to share their data and are even more reluctant to debate the issue while all the time proclaiming the "debate" to be over. They claim the science is settled. To my mind, if they claim the science to be "settled" then they don't know much about science or fear the truth.
Fox had the most balanced presentation of what is going on that I have seen on TV. If there has been something better showing both sides of the argument then I missed it and am willing to watch anything you think is better.
More later.

James Douglass said...

Aunt Mary- Thanks. :) It was bugging me that the "decline" phrase was being used over and over again and never having the context explained. I'm disappointed, but unsurprised, that they didn't explain the science behind it in the Fox show.

Al- Thanks for calling my dad and my attention to the show. I'll admit it wasn't as overtly biased as most of the other stuff I've seen on Fox, but it did pick and choose what to say and what not to say in a way that I think showed the idealogical bias you'd expect from a conservative network.

My tree-hugging environmentalism is no secret on this blog and I don't hide my feelings about stuff I don't like. I deleted the "ugh" at the beginning though, because after you said something about it I realized it wasn't a very good opener. Anyway, even though I'm a godless hippie liberal, I don't just blindly follow every "movement" that comes from the left. For example, I don't think genetic engineering and animal testing are necessarily bad, and don't think all kinds of welfare and social programs are necessarily good.

I thought Al Gore's film took a few liberties to dramatize the emotional message (a trick usually reserved for the right), but I also thought, with the exception of the stuff about increasing hurricanes, it was fairly well supported by the actual science. If the film did any harm, I think it was to make people expect too much big flashy disaster from climate change... Then when nothing that exciting happened right away, and maybe there were even some colder than usual days, they flipped the other way and jumped on the climate change denial bandwagon.

As for scientists proclaiming the debate to be over and settled and not wanting to share their data, I don't think that's good for the actual science or for the message of the science. But I understand the scientist's impulse to "circle the wagons", because its one of the only ways they can cope with the intense pressure from powerful groups that are financially and / or ideologically opposed to doing anything to reduce greenhouse gas emissions. The scientists know those groups will exploit any opportunity to attack research linking GHG to climate change, regardless of the research's merit. Scientists don't have anywhere near the amount of time and money for debating that the conservative lobby groups (funded by the oil industry) have. So they're sort of forced into acting like they have climate change completely figured out, when actually, even though they're pretty darn sure about the overall trend, they're still fussing quite a bit about the details of how much warming, when, etc.

Anyway, one of the guys I trust most to admit flaws and uncertainties and caveats to the climate issue is Jeff Masters.

am said...

James - I appreciate your further comments. I feel that many, if not most "scientists" and pretty much all the laymen vigorously supporting the idea (I won't call it a theory right now and I think we agree that it is not "settled science)are largely agenda driven. Meaning that they support some issue for which they can use the "impending doom" of AGW to further their cause. I am glad you mentioned your divergence with Gore on the hurricanes at least.
Some of the points which cast great doubt on much of the hysteria are: 1- The climate has always been changing and the world has been warming for about 12,000 years. Glaciers have been receding all that time (used to be ~1 mile thick around Cleveland, making an unnice place to live, not unlike now.)2- Sea levels have always been changing (used to be surf and primitive kite-boarding up around present day Orangeburg) 3- Many, if not all the "climate models" have not been able to forecast what happened in the past (had they been operational and I don't think any forecast the recent lack of warming over the last 10 years or so.

On the hurricane deal, many "prominent scientists" blamed the year of Katrina on AGW and spoke of them becoming inevitably worse and more numerable. Lately, including this past year, there have been almost a paucity of hurricanes. It is certainly, at least, disingenuous of anyone blaming the Katrina year on AGW to not come out and admit that they were absolutely wrong then and would have to be suspect now.
The claim "all scientists agree" on AGW is pure BS! I can provide a list of over 31,000 scientists that doubt much if not all of the "science" "proving" AGW. Of those, over 8,000 are PhD's.
I'll check out Jeff's stuff.
I look forward to further "chats" on the subject.


am said...

Oh, I firmly believe that the best, quickest and most proven method of reducing GHG emissions it to embrace and vigorously pursue nuclear powered electric generation.
Do you have a stance on that?

James Douglass said...

Al- Hey, thanks for the comments. :) I've heard that thing about the 31,000 scientists signing the "I don't believe global warming petition". There's more about it here...

I think the number of signatures is inflated, because the petition was designed to trick people into signing. That is, it was faked to look like exactly like a journal article from PNAS. Also, the "OISM" institute that made the survey is actually a shack in the woods in rural Oregon run by a couple of old kooks who are funded by ExxonMobile. Weird.

As for the signatories, I'm sure some of them are real, but I think the bulk are folks who were just duped by the language of the survey.

Regarding past climate variability, there are definitely a lot of things that affect climate besides AGW, like decadal-scale fluctuations in ocean currents, the Milankovitch Cycles that are responsible for the ice ages, etc.

But the climate scientists include all those kind of things in their models and they keep finding that the models don't predict current climate trends unless they include AGW, too.

As for nuclear power, yeah, it could be a quick fix, assuming we don't spill any radioactive goo or anything. But wouldn't we run out of uranium fuel in just a few decades if we used it as much as we now use fossil fuel?

Frank said...

You as a scientist should realize that there are no unbiast opinions at the start of data analysis.I and your father can remember when the next ice age was the consinsus.Just because everyone agress doesn't make it right. Mother Nature will change the landscape to suit herself with no reguard for human life whenever it she deam the time right. Man is distructive and self centered so he does what is best for him not mankin in all cases. No scientist wants to lose funding because he has not found a world changing problem. I believe that racism will never stop in the US because to many people make their living from it. Well this is the first thing I have read with no mention of Tiger Woods so I must being up his name to make it complete.

Merry Christmas

James Douglass said...

Merry Christmas Frank! :)

Jenny said...

In response to the argument that climate change is a natural fluctuation that cannot be attributed to human influence...

Can we at least agree that humans are contributing to the increase of CO2 in the environment, and that at the very least we don't want to exacerbate the "natural" global warming? Even if it is a natural cycle, it will still be damaging to our human societies and we need to address the issue. Isn't it better to take the precautions now and later find out that we aren't having as big an impact as we thought on the climate then not take the precautions and find out we were wrong? What happened to the supporters of a "preemptive strike"?

Morley said...

Seems like this is one of the most sensible and polite debates to be found on the subject on the Net!

I find it very depressing that so many otherwise highly intelligent people (I'm talking windsurfers here!) have been so quick to jump on the anti AGM bandwagon.

I have to take exception to some of "Al"'s statements. In particular: "Glaciers have been receding all that time" [since the Pleistocene]. No they most certainly haven't! Glaciers have been waxing and waning, but with several episodes of major growth offsetting the periods of melting; the first during the 'Younger Dryas' period about 11,000 calendar years ago when many of the Pleistocene megafauna went extinct during a cold snap of a few hundred years (some more controversial climate science, but there is some evidence that it may have been caused by a meteor strike. Google 'younger dryas' and 'nanodiamonds' if interested). The medieval warm period, when the Vikings were so successful at long-distance voyaging and grapes grew in southern England, was ended by a long cold period when many glaciers in much of the world grew. And Captain Cook was stopped from entering some of the fjords near Anchorage in the 1770s (or it may have been Cap't Vancover a decade later) because glaciers had advanced so much recently that many places had been recently cut off. Yes, glaciers have been changing in response to short-term climate shifts for thousands of years. BUt not like now!

In the southern Yukon these days there is archaeological rescue going on to try and recover stone and antler-tipped arrows, dart, and spear shafts from melting ice patches. THese non-flowing ice areas have gradually built up over thousands of years, but are melting at an extremely rapid rate nowadays, exposing the weapons lost over thousands of years. These are fragile wood, gut, and feather artifacts that have never before melted (since they soon rot)that are turning up almost every year.

In my province, we have seen our interior forests ravaged by mountain pine beetle. They used to be held in check by cold winters. We just don't have those winters any more. And it is not a 'natural' trend. And it isn't like a particular hurricane, that can't be blamed on climate change. Now most of those forests are dead. In many places, every single tree is brown. THe news said the other day that, instead of the forests being a carbon sink, the forests are now contributing something like a trillion tons of C02 into the atmosphere every year; which can't help the rise of greenhouse gases at all.

The northern part of Canada and much of Alaska and Russia is experiencing permafrost melt. These soils haven't melted in many thousands of years. They are now. And they are releasing staggering amounts of CO2 and methane into the atmosphere. I just read that a recent discovery is that the oceans seem to be doing something similar. It is a bit too much like a positive feedback loop for my comfort.

Global warming isn't just an idea made up by a bunch of ivory tower nerds. It is happening now and its effects are real for people to see. The Innuit language ("Eskimos") has been in place in the Arctic for millennia. THey never had a word for wasp, or many other insects of the temperate areas. They are needing them now.

James Douglass said...

Jenny- Thanks for bringing up the idea of precaution. Maybe Rumsfeld was right that we need to careful not only about the known knowns, but also the known unknowns, and unknown unknowns. :)

Morley- Thanks for chiming in with the more detailed historical perspective, and the eyewitness reports from Canada. Yes, some of those potential positive feedbacks on warming, like the melting permafrost and dying boreal forests, are worrisome.

am said...

James - a few further comments. I appreciate Morley's contribution and helping me make my point with the archeology showing that periods much warmer than now were apparently benign and civilization, such that it was, did fine and were later supplanted by cold periods without any contribution from or by us.
I did not mean to imply that glaciers had "always" or continuously been receding over the last 12,000 years but that over the long haul, the result is they have been since the last great ice age. Then they were in the area of present day Cleveland and a mile thick.
Your own comments poo-pooing the petition project are not very convincing. Here is the petition that we are talking about: "We urge the United States to reject the global warming agreement that was written in Kyoto, Japan in December, 1997 _ There is no convincing scientific evidence that human release of carbon dioxide _ will, in the foreseeable future, cause catastrophic heating of the Earth's atmosphere _"
I don't see how that is misleading at all.
Jenny's comments that any warming will be damaging to society is not supported by history as the recent (during written history) periods of warming were accompanied by much progress and prosperity by humankind.
Morley's contention that increased forestation is now contributing to the CO2 problem seems specious. I don't quite follow that logic. However, one must realize that all these fossil fuels we use today at one time existed as atmospheric CO2 themselves and it must not have caused all these apocalyptic problems that the "warmers" like to trot out to try to scare the "bejesus" out of everyone.
I listened to a lecture the other day and the speaker (a marine biologist) claimed that "99.5%" of scientists agree with the "warmers". Almost every scientist I know (present company excluded) is at least skeptical of the "science" of the warmers, if not of the belief that much of it is close to an outright hoax.
To paraphrase: (of the CO2) "We have nothing to fear of CO2 but fear itself"!
I appreciate the civility of all the comments thus far and hope it continues.
I enjoy your blog.

am said...

James - In one of your comments you mentioned that the computer models don't work unless they include the component of man made CO2. How would they (or you) explain away the recent trend of downward global temperatures? The entire "science" is that the man-made component is causing all the problems and raising the temperature. However, considering this recent quote: "According to the US National Snow and Ice Data Centre in Colorado, Arctic summer sea ice has increased by 409,000 square miles, or 26 per cent, since 2007 – and even the most committed global warming activists do not dispute this."?

Read more:
This, it seems to me, completely contradicts the basis for all the fear of rising CO2 levels. If the increasing levels are a cause, and they have not decreased (and I don't believe they have), the obviously something else is at play here. Perhaps we should find out.

James Douglass said...

Al- Thanks for sticking with this post. I still think the oregon petition was misleading and biased. Also, I'm not so sure the natural warming periods in the past few thousand years were always benign. The most often-cited example of past climate change affecting human cultures is the vikings getting frozen out of greenland at the end of the medieval warming period, but I think there are examples of cultures in other parts of the world that collapsed during times of warmer or drier weather. (How 'bout the dust-bowl in the 1930s?) It would be interesting to look into. Jared Diamond has a book called "collapse" that describes a lot of that history of human-environment interactions. I've been meaning to read it.

I don't think Morley's comment about dying boreal forests releasing CO2 is specious at all. When plants grow and accumulate biomass they remove CO2 from the atmosphere- when they die and rot they release it. If the dying and rotting is happening faster than the sprouting and growing, as is the case with the boreal forests plagued by the northward moving pine beetle, then the forest is a net source of CO2.

I understand your skepticism with the marine biologist's statement that 99.5% of all scientists are "warmers". But I think you and other skeptics tend to make a straw man of "warmers" by attributing to them the extreme, naive view that anthropogenic CO2 is the one and only cause of all variation in weather and climate. If that's what a "warmer" is, then there aren't many scientists who are warmers. On the other hand, if being a "warmer" simply means recognizing that increasing CO2 is a serious cause for concern as it relates to climate, ocean chemistry, and plant physiology, then I agree with the marine biologist that almost all scientists are "warmers".

2007 had BY FAR the lowest summer sea ice extent in recorded history. Even though 2008 and 2009 had greater ice extent than 2007, they still had relatively low ice extent and quite low average ice thickness compared with the historical average. I think that quote in the Rose article is being deviously used out of context to support the anti-AGW view.

Morley said...
This comment has been removed by the author.
Morley said...

Don't know if you go back and read comments for old posts, but this is one that should have some longevity.

I was just reading some of the 'skeptic' literature, and I must say there seems to be some fire beneath the smoke in terms of the way tree ring data, at least, has been selectively used and abused.
has some interesting specific observations. I fairly regularly review papers submitted for publication (archaeology and some for forestry) and I know that many reviewers are not as careful as they should be to examine problems in raw data or analytical methods used. Several times editors have thanked me and noted that no one else had identified the flaws. And I know and worked with another scientist who ended up discredited for overstating his results and having less-than-adequate testing for alternative hypotheses; funnily enough, he moved to another continent and is now doing very well in the same field. So I know that peer review itself can be sloppy.

I actually do know something about dendrochronolgy, and I was frankly surprised by the small sample sizes being used - and shocked by the apparent 'cherry picking' of data - that is discussed in that review. Getting climate data from a proxy like tree-rings is fraught with problems. Tree rings are very reflective of microenvironment, and things like a neighbouring tree falling and clearing some canopy space will clearly show up on an individual ring sequence. Trees that preseve the best for macrofossils are usually those growing on the shores of lakes or swamps - and they tend to be the least 'sensitive' to annual weather changes, as they are buffered by the local high water table, so they aren't as good a proxy as those growing on a dry ridge; but these don't often preserve. Etc, etc., etc., so to find out some of the crucial data used to demonstrate in papers published in the mid 2000s late historic warming is based on 5 or 10 samples is pretty surprising.

I saw one of my local colleagues here in Victoria is in the news and being pilloried in blogs for signing a recent petition as a sceptic. I'll have to ask her about how she got involved in that (I KNOW she has no ties to BIG OIL, etc).