Monthly Archives: December 2014

Global Temperature A Century Ago Vs. Today

With what may be the warmest year in centuries about to close, I thought it would be fun to have a graphic comparing the march of global average temperature over several years about a century ago with the present state of affairs. This graphic is based on NASA’s data, using John Abraham’s estimate for the 2014 temperature (it might end up being a tiny bit different). There is more information about those sources here.

[click on the graphic to get to a larger version]

Just to be clear on how to read the graph … the red dot is not anywhere in particular on the horizontal scale. The X and Y axis simply plot global average temperatures estimated for 1895 to 1933, a series of years that has 1914, a century ago, in the middle of it. This early sequence of data is meant to represent “pre-industrial” temperatures, and here that is compared using the single red to today, positioned correctly on the vertical scale (of temperature). Note, however, that 1895 to 1933 is not really pre-industrial. Human produced greenhouse gases were already being added to the atmosphere by then, though not to the same degree as more recent decades.

You will hear people say that even if 2014 is the warmest year on record, that it is not statistically significantly warmer than the next warmest year. That is absurd. One would have to have a very poor understanding of how statistics works to make such a statement non-ironically. But to make the point even more clear than I might if I explained why that is a dumb thing to say, statistically, I produced this graph which shows that today it is much warmer than it was not so long ago.

ADDED: A question has been raised as to whether or not I chose the proper scale on the Y-axis. I did. My intention was to show variation and average temperatures for several decades near the beginning of the industrial period, centering on 100 years ago, and to put the current year in context of that. This graph does that nicely, with no strangeness about axes other than the carefully explained fact that the clearly labeled 2014 datum is not scaled to the time scale on the bottom. The nature and variation of the entire instrumental curve is readily available and there are dozens of graphs here on this blog and elsewhere that show this (I placed one at the top of the post for your convenience). The point of this graph was to remove the ascending values and obviate the rather absurd question of statistical difference between the highest and second highest ranked years. As explained.

But the Y-axis problem emerges as a more general climate science denial meme (other than, and beyond, the relatively valid and honest question of how to best scale the Y-axis on a graph like this). And in relation to that, I’ve made a NEW ENTRY IN MY FAQ. Please have a look. There are some fun graphs.


To demonstrate two ways in which people get this wrong. First, an actual scientist type person simply believing (incorrectly) that all scales must start at zero (maybe they do in his field), and second, a climate science denialist actually arguing that the joke graph shown in the tweet is the best way to show global temperature change.

You might have to click on the pic to be able to read it:


Cry me a river: Joe Cocker has died.

Joe Cocker is (was?) one of my favorite musical artists. Having said that I quickly add that while his work is well represented on my list of favorites, I also really don’t like a bunch of his other work. But the stuff that’s good is great.

He died today at the age of 70.

One of the best “albums” you can get if you like rock and roll is Mad Dogs and Englishmen. It’s Joe Cocker and a bunch of other great musicians of the day, live, double album. On that album you will find Feeling Alright. Great song. I remember Amanda being very disappointed when she learned that the relevant statement from the song is not “I’m feeling alright” but rather, “You’re feeling alright, I’m not feeling so good myself” (because you dumped me and found somebody else, etc. etc.). Still a good song, though. And here it is:

For many years, it may have been true that Joe Cocker was the only artist who did the Beatles every bid as good as the Beatles, though of course different.

I’m lucky that I saw him in concert several times, including just recently.

Oh, and of course, his performance at Woodstock is legendary. Let’s do that too:

SO, Joe, now that you’re gone…


Bringing opinions on climate change closer to reality: Peter Doran

Enough! That’s Peter Doran’s opinion on the “debate” about a scientific consensus on climate change. There clearly is one — a strong one. So why do the public and the politicians think otherwise? Why the big disconnect between what the vast majority of scientists know to be fact, and what the public thinks. Dr. Doran blames the way media reports on science, and he blames a few of the loud voices on the right. He presents an idea to change a lot of the minds of people who deny the scientific consensus on climate change which will hopefully lead politicians to action. Peter Doran is a professor of Earth and Environmental Sciences at the University of Illinois at Chicago. He has published over 80 articles in the academic literature about the polar regions, lakes, ecology and climate change.

Here’s his OpEd.

New Research on Tree Rings as Indicators of Past Climate

A new study has recently been published that looks at the ecology of bristlecone pine growth at Sheep Mountain, and the tree ring signal those trees produce, at high altitudes in the Southwestern US. This is important because tree rings are an often used proxyindicator for reconstructing past climates. Those who keep track of the paleoclimate research will recall, for example, that tree rings were one of the proxyindicators used by Michael Mann and his team in constructing the famous “Hockey Stick” graph showing a dramatic increase in the Earth’s temperature since the onset of industrial times, when the instrumental record (of the last century plus) is put in context of previous centuries. Since then, tree rings have played an important role in past climate reconstruction.

I asked Malcolm Hughes, who was an author on that earlier hockey stick work and an author on the recent study discussed here, how his recent work informs us of the validity of Mann et al, especially in relation to bristlecone pine data used in that early seminal study. He said, “Back in 1999 we (Mann et al) made the best available choices with the information and data we had. Now, more than 15 years later, with a Bristlecone Pine record that extends back 5000 years, the original results hold up remarkably well.”

So, now, let’s discuss tree rings a bit and then see what the new paper offers.

Tree Rings And Past Climate

Past climates can be reconstructed by using proxyindicators of past conditions, much like more recent climate can be characterized by using instruments (thermometers, etc.) and data form satellites. One of these proxyindicators is tree ring width. Trees with seasonal growth may produce woody tissue at higher or lower rates depending on a limiting factor, such as available water or temperature. An individual tree may be limited by water availability if it is growing in a certain microhabitat, but a tree of the same species may be limited by temperature if it is growing in a different microhabitat. It is even possible for one limiting factor to control growth for a period of time, then, as conditions change, a different limiting factor takes over. Saplings and small trees growing in a forest may be limited by light, and later, as they grow tall enough (or gaps in the forest canopy open), they may be limited by moisture or temperature.

The tree rings from certain sites seem to properly reflect temperature variability up until around 1960, and after that, the usability of the signal from that proxy can be reduced. This pattern has been noticed in a number of different tree ring records; the phenomenon is widespread enough that it has a name. It is called the “divergence problem.”

Several explanations have been offered to explain the divergence problem, and there is a fair amount of literature on it. It is possible that the post industrial increase in atmospheric CO2 has affected tree growth (acting, essentially as airborne fertilizer) in such a way that the tree ring widths no longer reliably indicate temperature. Changes in the pattern of snow melt at high altitudes, which is where the temperature-sensitive trees are generally found, may affect growth patterns. Changes in minimum or maximum temperature distributions could be a cause. It is also likely that the amount of atmospheric dust (aerosols) has an impact on tree growth, so recent pollution could be a factor. The anomaly could also be an artifact of sampling large trees, in order to sample the longest time periods, if older trees have different growth patterns. In the case of one of the key proxy tree species, bristlecone pines, divergence may have to do with the fact that there are two different growth patterns at the tree’s surface, referred to as strip-bark and whole-bark.

In 2009, Matthew Salzar, Malcolm Hughes, Andrew Bunn, and Kurt Kipfmueller published a paper that looked at a possible divergence problem in bristlecone pines at three sites the American Great Basin. They looked at trees at the upper limit of elevation and found that “…ring growth in the second half of the 20th century … was greater than during any other 50-year period in the last 3,700 years.” This confirms that whatever the cause of divergence is, it is likely something going on during the most recent decades, which strongly suggests a cause related to Industrial Era pollution or warming. They were able to rule out changes in tree growth patterns and fertilization by added atmospheric CO2. They note that “[t]he growth surge has occurred only in a limited elevational band within ?150 m of upper treeline, regardless of treeline elevation,” and concluded that “[i]ncreasing temperature at high elevations is likely a prominent factor in the modern unprecedented level of growth for Pinus longaeva at these sites.”

A New Study On How Tree Rings Work

More recently an overlapping set of authors have published an important study (“Changing climate response in near-treeline bristlecone pine with elevation and aspect”) that looks at this problem in more detail. From the abstract:

In the White Mountains of California, eight bristlecone pine (Pinus longaeva) tree-ring width chronologies were developed from trees at upper treeline and just below upper treeline along North- and South-facing elevational transects from treeline to ~90 m below. There is evidence for a climate-response threshold between approximately 60–80 vertical m below treeline, above which trees have shown a positive growth-response to temperature and below which they do not. Chronologies from 80 m or more below treeline show a change in climate response and do not correlate strongly with temperature-sensitive chronologies developed from trees growing at upper treeline. Rather, they more closely resemble lower elevation precipitation-sensitive chronologies. At the highest sites, trees on South-facing slopes grow faster than trees on North-facing slopes. High growth rates in the treeline South-facing trees have declined since the mid-1990s. This suggests the possibility that the climate-response of the highest South-facing trees may have changed and that temperature may no longer be the main limiting factor for growth on the South aspect. These results indicate that increasing warmth may lead to a divergence between tree growth and temperature at previously temperature-limited sites.

Generally, trees from higher latitudes (farther north) and higher altitudes both make better temperature proxies, because the two factors (altitude and latitude) both have temperature as a common thread. You learned this in your middle school Earth Science class. Altitude and latitude mimic each other to a large degree, which is why mountain glaciers can be found on the equator (or, at least, were found there before global warming mostly melted them away). But this new research also shows that topographical position in relation to the sun (south facing vs. north facing) further modify the microenvironment the trees are growing in.

Three earlier studies by Salzer and others (in 2009, 2013, and 2014) show is that the 20th century growth increase at the very highest elevations is temperature related, so in that sense, there has not been a divergence problem in the bristlecone pine, although one may now be emerging on the south- facing slopes, but not on the north-facing slopes near treeline.

The importance of microenvironment is well illustrated in this figure:


This shows the tree ring values for two sampled sites from 1980-2009. Until the mid 1990s, the tree ring values correlate tightly. After this point in time, however, they demonstrate the divergence problem among the samples, in this case, caused primarily by the specific direction the locations are facing (north vs. south).

The most important conclusion of this paper (which is not a reconstruction of past climate, but rather, a study of the ecology of tree ring growth) has to do with how tree ring data are assembled and used. Multiple tree ring samples may be taken from a given site, with the assumption that that site has similar conditions for all the sampled trees, so the assembled and combined tree ring data will have a similar climate related signal. (Note that there is a fair amount of internal variability within a given tree that is hopefully erased when more than one sample from a given site is used). Salzer et al show that at high elevations bristlecone pines can vary from each other considerably if they are sampled form elevations that differ in several tens of meters, or in the aspect (direction) of the slope they grew on, and that this sensitivity is tied to the treeline at on a given slope. And, of course, the position of the samples (as noted above) affects the degree to which tree ring data reflect temperature as opposed to other factors.

We have shown that approximately 60–80 m of vertical elevation can be sufficient to create a change in the climate response of bristlecone pine. Trees below this elevation are not as effective temperature recorders as trees at treeline. Such fine-scale sensitivity, if present at other treeline sites around the world, would have important implications for chronology development and inferences of past climate variability. Treeline site chronologies should be constructed with this vertical heterogeneity in mind. Samples from upper treeline and from trees below treeline should not be mixed to avoid a ‘diluted’ or ‘mixed-signal’ site chronology, particularly at treeline sites that occur in relatively dry environments such as the White Mountains of California. Similarly, treeline samples from differing aspects should not be mixed to avoid problems and uncertainties related to potential ‘divergences’ and to ‘dilution’. Interpretations of existing bristlecone chronologies need to take this into account, particularly when these ring width chronologies are used in climate reconstructions.

I asked Malcolm Hughes and Matt Salzer, two of the study authors, how to best characterize this study. They told me that this paper is, for the most part, “…an ecological study. There are no climate reconstructions, rather mostly comparisons of growth from trees growing in different spots on the landscape. There are paleoclimate implications. We still find temperature sensitive bristlecone pine trees at upper treeline; they simply don’t extend down the mountain as far as we used to think. In addition, some of the treeline south-facing trees seem to be less influenced by temperature in recent years than they used to be. The location of the trees, and understanding what environmental variable is limiting growth at that location, is the key to developing accurate paleoclimatic reconstructions from tree rings. Science is a continuous process of improvement.”

Earlier research by an overlapping team also looked at topography. In “Topographically modified tree-ring chronologies as a potential means to improve paleoclimate inference” by Andrew Bunn, Malcolm Huges, and Matthew Salzer (2011) it is noted that

…a mean ring-width chronology from a particular site may be composed of trees from highly varied topographic positions. Such a “topographically-mixed” chronology can be confounded in terms of its climate signal. For example, ring widths of trees that are primarily recording summer temperature might be averaged with ring widths of trees that are primarily precipitation recorders.

That paper details how researchers can use topographic setting to separate different growth series to produce a cleaner sample for developing a temperature proxy. Like the more recent paper discussed here, Bunn et al is an effort to improve the methodology of using tree rings as a proxy.

Science Denialists Can’t See The Forest Through The Tree Rings

Even as the tree-ring proxyindicator expands in size (more samples) and is better understood (from the above mentioned studies) climate science denialists remain entrenched with their assertion that tree rings are bad proxies, or are being used incorrectly. These criticisms are not legitimate critiques of the science, but rather, combine obfuscation and misinformation to muddle and confound thinking about tree rings. An early example of this comes from the kerfuffle known at “climategate” in which electronic communications among climate scientist were stolen and mined for decontextualized quotes that could be used to lie about the science itself and the motivations and activities of the scientists who developed the Hockey Stick curve. Michael Mann chronicles these events in his book “The Hockey Stick and the Climate Wars: Dispatches from the front lines.”

One e-mail Phil Jones of CRU sent to my coauthors and me in early 1999 has received more attention than any other. In it, Jones both made reference to “Mike’s Nature trick” and used the phrase “to hide the decline” in describing a figure … comparing different proxy temperature reconstructions. Here was the smoking gun, climate change deniers clamored. Climate scientists had finally been caught cooking the books: They were using “a trick to hide the decline in global temperatures,” a nefarious plot to hide the fact the globe was in fact cooling, not warming! …

The full quotation from Jones’s e-mail was …, “I’ve just completed Mike’s Nature trick of adding in the real temps to each series for the last 20 years (i.e. from 1981 onwards) and from 1961 for Keith’s to hide the decline.” Only by omitting the twenty-three words in between “trick” and “hide the decline” were change deniers able to fabricate the claim of a supposed “trick to hide the decline.” No such phrase was used in the e-mail nor in any of the stolen e-mails for that matter. Indeed, “Mike’s Nature trick” and “hide the decline” had nothing to do with each other. In reality, neither “trick” nor “hide the decline” was referring to recent warming, but rather the far more mundane issue of how to compare proxy and instrumental temperature records. Jones was using the word trick [to refer to] to an entirely legitimate plotting device for comparing two datasets on a single graph…

The reconstruction by Briffa, (see K. R. Briffa, F. H. Schweingruber, P. D. Jones, T. J. Osborn, S. G. Shiyatov, and E. A. Vaganov, “Reduced Sensitivity of Recent Tree-Growth to Temperature at High Northern Latitudes,” Nature, 391 (1998): 678–682) in particular …

…was susceptible to the so-called divergence problem, a problem that primarily afflicts tree ring density data from higher latitudes. These data show an enigmatic decline in their response to warming temperatures after roughly 1960, … [Jones] was simply referring to something Briffa and coauthors had themselves cautioned in their original 1998 publication: that their tree ring density data should not be used to infer temperatures after 1960 because they were compromised by the divergence problem. Jones thus chose not to display the Briffa et al. series after 1960 in his plot, “hiding” data known to be faulty and misleading—again, entirely appropriate. … Individuals such as S. Fred Singer have … tried to tar my coauthors and me with “hide the decline” by conflating the divergence problem that plagued the Briffa et al. tree ring density reconstruction with entirely unrelated aspects of the hockey stick.

Note that there wasn’t a “divergence problem” in Mann et al in the sense of Briffa et al. Mann et al match the observational record very well through 1980, which is the end of the calibration interval (owing to the fact that many proxies drop out after 1980). This is something else the deniers tend to get wrong; they try to conflate the Briffa et al post-1960 divergence problem Mann et al’s hockey stick work. There is no such issue with that work, in that there was no detectable divergence through the end of the calibration interval.

Related to this, there was a correction of the Bristlecone Pine data for inflated 20th century increase (which was attributed to CO2 fertilization at the time) in MBH99. So we actually applied a downward correction of the trend in those data. McIntyre doesn’t want people to know that. So need to make sure that is crystal clear.
More recently, climate science denialist JoNova took the new paper by Salzer et al to task using equally mind numbing arguments. JoNova notes that “after decades of studying 800 year old tree rings, someone has finally found some trees living as long ago as 2005. These rarest-of-rare tree rings have been difficult to find … The US government may have spent $30 billion on climate research, but that apparently wasn’t enough to find trees on SheepMountain living between the vast treeless years of 1980 to now.”

I’m sure the scientists involved in tree ring research would like to know where their $30 billion dollars went, but that’s another story. I asked Malcolm Hughes about JoNova’s implication that there has been next to zero research on or with bristlecone pines over these many years. He said, “This post makes a big deal about the lack of updating of bristlecone pine chronologies since 1980. This is simply wrong. She fails to acknowledge that in 2009 we published on bristlecone pine growth rates in PNAS (Proceedings of the National Academy of Sciences) and put tree-ring data from Sheep Mountain out to the year 2005 in a publicly accessible archive.”

JoNova also implies that the lack of tree ring proxy use for periods after 1980 is somehow suspicious, but as detailed at length above, the divergence problem is, well, a problem. Also, further work such as that reported here is likely to revive some of that data and allow it to be used, eventually. At the very least, future work with high altitude/latitude tree ring data will be improved by these methodological and ecological studies.

Climate science denialist Steve McIntyre has also weighed in on Salzer et all’s research. His post is truly mind numbing, as he treats Salzer et al as a climate reconstruction paper, and critiques it as such, but the paper examines the methodology of tree ring proxy use and the ecology of tree rings. McIntyre shows the same figure I show above (Figure 5 from that paper) and critiques the researchers for failing to integrate that figure or its data with Mann et al’s climate reconstructions. But they shouldn’t have. That is not what the paper is about. Another very recent paper by the same team is in fact a climate reconstruction study (published in Climate Dynamics) but McIntyre manages to ignore that.

Science writer and failed banker Matt Ridley has also applied his abysmal understanding of paleoclimate science with a critique of some of this research.

I’m sure you find these esoteric details of tree ring chronologies fascinating, but there is a point that needs to be made that is even more interesting.

Ever since Mann et al published the famous “hockey stick graph” those in the business of denying or (inadequately) refuting the growing consensus of climate science have made much hay out of both the divergence problem and a sense of suspicion of the tree ring record. For examples of this, read through the comments on this post. If you read comments by those who seem bent on the idea of refuting the reality of global warming, you’ll get the impression that there are only a few tree ring chronologies, we have no idea how they work, they don’t work, that climate scientists pretend they stop working at some point when really they are working but show cooling (which we know didn’t happen because we have thermometers) and, generally, that tree ring science is some sort of exercise in voodoo.

What has really happened, however, is that tree ring data have behaved pretty much as any other paleoclimate proxy behaves. There are conditions under which any given proxy works, and there are conditions under which the proxy can’t be trusted and should not be used. Decades ago, when the Hockey Stick was first formulated, the loss of signal in the tree ring record was somewhat mysterious, though numerous good ideas explaining it were out there. Subsequently, there has been a considerable amount of research adding new tree ring data, and some of that research has focused on teasing out the methodological and ecological details of this particular proxy. Interestingly, the last 10 years or so of tree ring research has failed to force the conclusion that tree rings are not good sources of past temperature data; the divergence problem is replicated in other records showing it again to be a recent phenomenon; change in regional (and global) temperature is increasingly implicated as the cause of the divergence problem; and much finer details of how this all works, at the scale of tens of meters elevation and at the level of details of topography have been worked out.

References and related items

2014 may be the warmest year on record

In early December I wrote a post called “2014 will not be the warmest year on record, but global warming is still real.” The very first thing I said in that post is that I was going out on a limb. I also discussed whether or not one year mattered, and I discussed the nature of the phrase “X is the Yth warmest year on record,” going into details on what “the record” is and how we measure this.

I want to reiterate something very important that I mentioned then. Here, we are talking about a combination of measurements from the sea surface and the air just over the land (about where your head is when you are walking around). Changes in this surface measurement over time reflect less than about 5% of the overall changes in temperature experienced by the Earth because of the addition of greenhouse gasses to the atmosphere (or reduction of “sinks” of those gasses, or of heat) by human activity. Most of the additional heat goes into the ocean.

The reason I was conservative in my earlier post was to avoid a situation where we (climate scientists, climate science communicators, etc.) made statements about 2014 that turned out to be wrong in a subset of the records, of which there are several. That is still possible, I suppose. But, now that we are past the middle of December, it is possible to estimate December’s overall temperature, add that to the prior 11 months, and say with much more certainly that 2014 will be the warmest year.

My friend and colleague John Abraham has been doing just this. He’s been collecting data on daily temperature estimates (I helped a bit, covering that task when he was overseas and unable to do so himself). He then took this information and, essentially, asked himself the same question every day: “Do I have enough data to call this?” Over the last several days NASA and NOAA have updated their temperature records for November, and NOAA came out with an analysis showing how difficult it would be for 2014 to NOT be the warmest year in their records. When John Abraham combined his analysis with the data through November, he decided, yesterday, that it was time to call it.

…2014 will be the hottest year ever recorded.

I can make this pronouncement even before the end of the year because each month, I collect daily global average temperatures. So far, December is running about 0.5°C above the average. The climate and weather models predict that the next week will be about 0.75°C above average. This means, December will come in around 0.6°C above average. Are these daily values accurate? Well the last two months they have been within 0.05°C of the final official results.

The graph above shows the NASA data by year, in standard units (0.01 Celsius anomaly using a base period of 1951-1980) with John’s estimate for 2014 added to the end. This will change slightly after NASA gets the December data out.

Remember, this is the instrumental record, which goes back into the 19th century. But when we look at proxyindicator data for previous centuries or millennia, we don’t see any evidence suggesting that there were any, or if there were any, that there were many, years that would have been warmer for a very long time. That goes back through the entire Holocene. Before that, it is harder to make that claim. There is a good record over the last several glaciations, say bout 800 thousand years or so, for which we can say that the present level of global surface temperature is in the range of the warmest periods, or at the top end of the range. This becomes less likely as we go back in time, as there has been a general cooling of the earth (with a lot of ups and downs) since some time in the Miocene (over 5 million years ago).

However, paleorecords together with basic physics tell us that the current level of CO2 in the atmosphere should associate with a much higher temperature than we experience now. This is why the Earth’s surface temperature is going up. The added CO2 is a little like adding fire to the bottom of a pot f water. The water will eventually reach boiling point, but it will take some time. Because of the way heat (and to some extent, added CO2) circulate among the various reservoirs on the Earth’s surface, a process that might take a geological instant on a simpler planet (rocky surface, no significant water including no significant oceans, simple Nitrogen atmosphere) takes much longer. We are not sure how warm the Earth will get with 400ppm CO2, which is about where we are now, but it is quite a bit more than the present temperature. That number, even if it is on the low end of the possible range, likely exceeds ancient temperatures for very long time. The fact that we are continuing to add CO2 to the atmosphere, and even them most intense efforts to reduce this are going to take time, means that we can expect a much higher concentration of CO2, and thus, an even higher eventual level of warming. Over coming decades, we will be recording “warmest years” that are warmer than anything in millions of years.

Also, there are at least two additional factors that must be taken into account. One, perhaps most important, is that the rate of change we are currently experiencing is high, perhaps unprecedented in many millions of years. Rapid rates of change is bad. Second, and in part a subset of the first (but not perfectly) is the problem of circumscription of our agriculture and infrastructure, as well as natural preservation areas. When they build roads in Mississippi vs. Minnesota, they build them differently because of the climate. As the climate warms, the old roads turn out to be built wrong and have to be redone to handle a different range of temperatures. That’s a small problem, because we rebuild our roads now and then anyway. Because of changes in temperature and rainfall patterns, the irrigation infrastructure for agriculture will become inappropriate to the task in some regions. That is a larger problem. As warming occurs, parasites from southerly areas move north, and find populations of plants and animals that are not adapted to them. Forests die, large mammals go locally extinct, etc.

Slowly slowly, we are getting to the point where it might be safe to bring back some of the dinosaurs! (Except they would starve because the plants the herbivores eat are rare or extinct. The carnivores could find food, though, I suspect…)

So, go read John Abraham’s post.

A Second Helping of Turkey

Are you done with your Thanksgiving leftovers yet? You might think so, but not quite. We have one more helping of Turkey for you.

This is “Another Helping of Turkey,” the second of two installments of Eat This Podcast with Jeremy Cherfas:

The domestication of the turkey probably first took place around 2000 years ago in south central Mexico, possibly for their feathers and ritual value rather than their meat. Their rise to the top of the American festive table came much later, not with the Pilgrims but with Charles Wampler, whose efforts to promote turkey raising started Rockingham County, Virginia, on its path to Turkey Capital of the World. That much we heard in the previous episode of Eat This Podcast. In between domestication and proto-industrialisation, however, the wild turkey almost vanished from America, hunted to the edge of extinction. Nature types – and hunters – really thought the turkey was a goner, and it was the hunters who brought it back, to the point where there are now turkeys in 10 states, including Hawaii, that originally had none….

Read the rest here, and listen to the podcast (in which I, as well as various turkey experts, am interviewed) HERE.

The previous podcast, “A partial history of the turkey,” is here.

What is Greenpeace going to do about Nazca?

ADDED NOTE: I changed the name of this post because some chose to shift the focus of the discussion from Greenpeace’s horrendous act in Peru to whether or not my reaction is appropriate, as though I had done damage to some historic site or harpooned a whale. I live in Minnesota. I am not affected by arguments that certain reactions to a crime make the crime tolerable. But I want to take the focus off me, and return it to Greenpeace. The rest of this post has also been modified to include a statement that makes very clear why what Greenpeace did was wrong, and why it is alarming and requires very a very explicit and strong response from Greenpeace.

Another excuse that has been given is that Greenpeace is big and complex and contains many parts, only one of those parts involved in the desecration of a heritage site. This is true enough, and does related to parsing what actually happened and deciding which individuals should turn themselves in to the Peruvian authority. But it is also true that Greenpeace as a brand is a powerful thing, and that brand is what is at stake here. Look at the damn picture they made. It says “Greenpeace.” It does not say “Some subset of Greenpeace, not all of Greenpeace.”

A man who loots a Native American site in an area he needed a permit to access may have his ability to get a permit to enter that area taken away for life. Greenpeace did something similar, but possibly much larger than what any one person in search of some pottery to sell could have done. So, what should happen to make this right? I have also been criticized (privately) for apparently indicating that I know nothing of the great things Greenpeace has done in the past, from a reading of the first paragraph of my original post (below). Sorry, but that is entirely beside the point and also inaccurate. “I’m sure Greenpeace has done a lot of great things” is a bone I’m throwing to Greenpeace for one purpose and one purpose only; I’m not too interested in entertaining right wing slams on a major environmental organization that has done a lot of good. Take it or leave it.

I’m sure Greenpeace has done a lot of great things, saved some whales, etc. etc., but the organization has recently carried out an abominable act that requires the institutional equivalent of a very very long jail term, or, what the hell, let’s make it a death sentence. Greenpeace needs to shut down as an organization. Right now. People’s objection to this strong statement has taken the spotlight off of this horrendous act, so I crossed it out. I still think it, but now maybe the focus can go back on Greenpeace.

Greenpeace activists entered a restricted area in Peru, where the Nazca lines are located. They drove into the area, and walked around there, and laid out banners. The banners were then photographed from the air (from a drone, as I understand it) to produce a message supporting renewable something. I’m guessing energy. The message was not clear. Nor was the link between their big yellow banners and the sacred and ancient Nazca lines.

This is an abuse of the cultural patrimony of Peru and the native people’s who have lived there.

In this fragile environment, footprints constitute irreparable damage.

One of the Nazca lines was apparently damaged directly, the area around the lines trodden.

As an advocate of renewable energy and supporter of taking action to move in that direction, and an archaeologist, I deeply resent Greenpeace using the Nazca lines as a propaganda tool, and I condemn Greenpeace for thoughtless damaging this important archaeological site.

I can see going after a whaling ship, illegally. But what exactly did the cultural and historical patrimony of Peru, what exactly did the extraordinary unique archaeological site of Nazca, ever do to a whale, or the environment, or to the environmental movement, or to Greenpeace?

All those who love and respect the past and archaeological resources, and who at the same time feel that we need to act on important issues such as climate change (and saving the whales) need to step away from Greenpeace and find a different organization or activity to support.

I call for the appropriate leadership of Greenpeace to resign, the board of directors to resign, the organization to turn all those involved (including in a supervisory capacity, and a planning capacity) over to the Peruvian authorities for prosecution, and for the organization to abrogate itself as the only way to truly express the appropriate level of shame and remorse. Greenpeace needs to cease to exist as a show of deference to a cultural symbol that will likely outlive humanity itself. Again, modified to shift focus. Greenpeace is dead to me. But what will provide redress? At the very least, Greenpeace needs to create, publicize, and implement a policy that prohibits the use of cultural heritage as a tool in its activism.


Greenpeace has been willing in the past to break the law. That is what they are famous for, and it is probably where they have been most effective. Not only have they broken the law, but they’ve broken the Law of the Sea, which is one of the oldest and most traditional cultural concepts we have in the west. They have, effectively, committed piracy.

This was done for a greater good, and turns out (as I understand it) to have been pretty effective activism, partly because every act of piracy to save a whale does get a huge amount of attention (and has other whale saving effects). It helps that the bad guys are really bad, and the good guys are innocent whales. This is not just civil disobedience, which at certain times and places people grow inured to. This is spectacular, it is dangerous enough to die doing, it is not something where they book you and a thousand others and let you go later that day.

It is impossible to not respect this, but it is also necessary to recognize what it is at the core. This is an organization deciding to systematically identify and intentionally break a certain category of national (from various countries) and international (as vague as that may be) law for a greater good.

With this act in Peru, Greenpeace has made a clear statement. It is a clear statement because this was an act that required organization, funding, decision making, meetings, an OK from various levels up and down the line, etc. at least within the unit of Greenpeace involved. They’ve made a clear statement that Greenpeace as an organization is willing to break the law in an entirely new area. They are willing to violate laws that protect heritage sites. That is a new thing as far as I know for them (though I’ve heard otherwise, see links below). And it is deeply disturbing. It can’t be just a few people involved in this and incidentally using the Greenpeace name.

And it isn’t just breaking the law. Any operation involving Nazca would involve research and knowing something about what they are up against. You can’t plan a project using Nazca and not be aware of the delicacy of the environment, of the fact that numerous people and one or more vehicles on the ground will unavoidably ruin parts of the site. Leaving a footprint at Nazca is like leaving a footprint on the moon (almost). It is nearly as permanent as the lines themselves. Everyone who knows anything about Nazca knows this. These Greenpeace activists must have known this.

So, Greenpeace has made a SECOND statement with this act. Greenpeace has clearly shown that it is willing not only to break Heritage laws in some trivial and non destructive way, but Greenpeace as an organization is willing to physically and permanently damage heritage sites. Imagine for a moment the reverse; harpooning a whale to save a pyramid.

Greenpeace has also made a THIRD statement with this act. Greenpeace has indicated that it is willing to break heritage law, AND damage a heritage site, for the purpose of making a picture. No whales were saved during the partial eternal destruction of a heritage site. No gyre of garbage was cleaned up while the regional indigenous culture was unceremoniously thrown under the bus. If there was a heritage site who’s preservation was actually doing the equivalent of killing whales (there are such conflicts though mostly involving plants) this might make sense. But this was a heritage site utterly unrelated to anything in the way of conservation or environment being exploited because it is famous to make a vague and not especially effective message.

Looking at this strictly from the point of view of a Greenpeace supporter, consider the implications. Now, there is a photograph of a major, very well known (one of the most well known non-Egyptian sites) locality with a message superimposed on it that, regardless of the intention, says “Greenpeace is willing to damage a heritage site” written across it in orange.

So, the final point is this: Greenpeace is known as an organization willing to break laws, in a big way, to make a larger point. Now, Greenpeace tell us that it is willing to include Heritage laws in that activism. Apologies, consternations, statements of conciliation are not of any interest to me at this point. The individuals and communities that support indigenous rights and heritage can’t afford to extend trust in this sort of situation.

There may be a point where Greenpeace’s response to their own atrocity is sufficient. But I’m 99% sure Greenpeace will never be able to pull off that response.

Some related links:

<li><a href="">Greenpeace apologises to people of Peru over Nazca lines stunt</a></li>

<li><a href="">By wrecking an iconic archeological site, Greenpeace ruined the UN climate convention for Peru</a></li>

<li><a href="">Peru Is Indignant After Greenpeace Makes Its Mark on Ancient Site</a></li>

John Kerry in Peru on Climate Change

It is nice to know that the 97% consensus on climate change science is assumed to be a real thing by the leaders. This is John Kerry talking about climate change, in Peru.

He notes that scientists were telling us that climate change is real and already happening in 1988, and he notes that in Rio 1992, the UN Secretary General delcared that he was persuaded that we are on the road to tragedy. He mentioned the superstorm happening now on the West coast and says, “It’s become common place now to hear of record breaking weather events.”

The psychology behind our failure to act on climate change

Chris Mooney writing for the Washington Post has an article on “The 7 psychological reasons that are stopping us from acting on climate change

He notes:

When a gigantic threat is staring you in the face, and you can’t act upon it, it’s safe to assume there’s some sort of mental blockage happening. So what’s the hangup? That’s what a new report from ecoAmerica and the Center for Research on Environmental Decisions (CRED) at Columbia University’s Earth Institute — entitled Connecting on Climate: A Guide to Effective Climate Change Communication — seeks to help us better understand.

The report is framed around communicating about climate change effectively — but read more closely and you’ll quickly see that the reason we need help here to begin with is that humans have some pesky attributes, ones that render us pretty poor at grappling with slow-moving, long-range, collective problems like climate change. So which traits are we talking about?

Read the rest here.

Fisking a typical climate science denialist comment

This one is worth looking at because it was published as a letter to the editor in an actual newspaper. Or, at least, on the web site.

A little background is in order. First, Dennis Slonka wrote an Op Ed in the Providence Journal telling us that “Climate Science Will Never Be Settled.” In it he made a number of incorrect statements about climate science, the IPCC, and Michael Mann. Then, Mann wrote a response that corrected the record. At some point, the Providence Journal corrected a small part of Slonka’s post, removing a blinding error, which demonstrates Slonka’s abysmal understanding of the situation (“This column has been edited to remove an error. No jury has found for Mann’s critics, and his defamation lawsuit is proceeding in court”).

Mann’s Op Ed is one of the rare places you’ll see him referring to his law suit, as, I assume, as a plaintiff he is probably advised to not talk about it much. He says:

If it wasn’t for all that extra CO2 in the atmosphere, Earth would be slightly cooling right now. Dozens of independent peer-reviewed studies have reached the same conclusion: rising temperatures and sea levels are directly related to the CO2 released into the atmosphere over the past two centuries by fossil fuel burning and other human activities.

More importantly, climate deniers aren’t asking questions in good faith. They’re persecuting researchers whose findings they don’t like.

I’ve written about my own strange encounters with climate denial in “The Hockey Stick and the Climate Wars” in the hopes that my colleagues — and the interested public — can learn from these experiences.

Indeed, attacks on scientists are nothing new. The lead industry went after Herbert Needleman, who found lead exposure impaired childhood brain development. Big Tobacco targeted public health researchers. Even the National Football League marginalized researchers who studied how players suffered from repeated concussions.

Some industry-funded groups and “think tanks” continue to smear me and pretend that my research is the linchpin of all climate science. But other scientists, who understand and have thoroughly reviewed my work, know my detractors have no idea what they’re talking about.

I finally decided to sue two groups that accused me of fraud in particularly insulting ways; contrary to Mr. Slonka’s claim that a jury had already ruled in the matter, my case is actively moving through the court system.

Despite the difficult position I find myself in in the climate debate, there is reason for hope…. (read the whole Op Ed here)

Within what seems like minutes of Mann’s Op Ed coming out, Providence Journal published a letter from a reader, George W. Shuster, responding to Mann’s post. It is almost like they had it ready. I wonder if the Providence Journal is aware of the fact that most Major Media are, these days, starting to pull back form the “false balance” position that there are two sides to the global warming “debate.” Anyway, here is George W. Shuster’s letter (George W. Shuster: Mann ignores geological facts) Fisked by yours truly. There isn’t much in the letter to begin with so this won’t take long.

Professor Michael Mann’s Dec. 11 Commentary piece (“Global warming’s dangers stare us in the face”), is typical of so many in the so-called “consensus” in that it: conflates the fact of long-term global warming with short-term “man-made” global warming; and selectively denies the sciences of geology and paleontology.

There is no “so-called” consensus. There is a consensus. It looks roughly like this:

Screen Shot 2014-12-11 at 12.19.04 PM

Also, Michael Mann has used the paleo record in his research and is quite familiar with it.

To pick just one example, Mann expresses great alarm that the sea level has risen 8 inches since the 1880s. What he fails to mention, which someone objectively recognizing the sciences I’ve cited would take into account, is that we are still coming out of the Ice Age, which has seen sea levels rise some 400 feet in the last 20,000 years. (Our beloved Block Island was once part of the mainland, and Rhode Island’s land area was much larger).

This is in correct. I’ve actually studied sea level rise in New England, when I was doing a lot of archaeology there. Sea level rise had mostly slowed or stopped prior to the Industrial period as far as we can tell, and given the most likely scenario in the absence of global warming, it was more likely that the sea level would lower a bit over coming centuries.

In fact, the rate of increase Mann agonizes over since the 1880s is actually far less than the average rise over the longer term. The long-term rate over 20,000 years comes to almost four times the rate of rise since the 1880s.

Sea level goes up and down a great deal over the long term. During the latter half or so of the Pleistocene, sea level went up and down well over 100 meters. But the current sea stand, roughly, is close to the maximum normal level for this period. (See the graph at the top of the post showing long term sea level rise, from here.) Comparing the rate of sea level rise now to the average change over 20,000 years is roughly like comparing the growth rate of a 40 year old human to the growth rate of the same person as a toddler. Interesting, but not relevant to the present situation.

Global warming is a serious issue, but the proper response should not be dictated by science deniers such as Professor Mann, who selectively pick which sciences they find handiest to recognize, and deny any others that provide inconvenient truths.

Yes, indeed, global warming is a serious issue. But calling Michael Mann a science denier is not only absurd, but it is what I refer to as a bully tactic. Bullies paint their prey with the same labels that could legitimately be applied to themselves, and often label themselves with tags that are more appropriately applied to their victims. George has at least one other letter in the same newspaper in which he refers to a champion of science in the Senate as a science denier, so this isn’t a mere slip on his part. It is a tactic.

Michael Mann has written a lot about climate change, and given many talks and interviews. But underlying all of this is his own body of peer reviewed research which has been closely examined by others in the scientific community. I’ve read pretty much all of that research myself. I can let you in on a little secret. Michael Mann is embroiled in an intense debate with other climate scientists about an important issue that is totally unsettled. It is a true debate. They are arguing over the data, its interpretation, and what it means. The debate is about the important question of what happens to tree growth shortly following major volcanic eruptions. Mann says it is likely that some trees are so badly affected by the short term climate change caused by the volcanic eruptions that they essentially stop growing, which messes up a small part of the long term record the tree rings from these plants are normally used for to track climate change over time. Others say this doesn’t happen and the record is fine the way it is, but rather, what some think about the effects of volcanic eruptions on climate, and indirectly, on trees, is not exactly right.

That, ladies and gentlemen, is a debate. A scientific debate. The outcome of that debate will not affect the overall picture of climate change, but it will have an important influence, possibly, on how we calculate the rate at which increasing greenhouse gas will warm the surface of the Earth. (Long term the same outcome will probably happen, but if volcanic effects are stronger, there may be more periods of slightly less rapid warming.) Esoteric, detailed, important, not paradigm changing, not an inconvenient truth, and to most people, mind numbingly boring if you get into the details. But it is an example of the kinds of debate that are real in climate science. The uncertainty introduced by George W. Shuster in his letter are only in his head. He has this wrong, which is fine, because (I guess, but it is obvious) he is not a scientist in this area of research.

Happy Anniversary Real Climate

Ten Years of RealClimate

In the spring of 2004, when we (individually) first started talking to people about starting a blog on climate science, almost everyone thought it was a great idea, but very few thought it was something they should get involved in. Today, scientists communicating on social media is far more commonplace. On the occasion of our 10 year anniversary today it is worth reflecting on the impact of those changes, what we’ve learned and where we go next.

Why we started and why we continue

RealClimate is one of the more important climate science blogs out there. If you don’t know about it, you should!

Read the rest of the story here.

Global warming’s dangers stare us in face: Op Ed by Michael Mann

The Providence Journal has published an Op Ed by climate scientist Michael Mann. You should read the whole thing, but I found the following paragraphs to be one of the better written descriptions of the situation we are in:

Here’s what my fellow scientists and I know: Thermometers and satellites all point to the fact that the world is rapidly warming. Glaciers are shrinking, the ocean is heating and expanding, precipitation is falling in heavier doses, and we’re watching the Arctic icecap shrink away.

Why the rapid warming? Heat-trapping carbon dioxide in our atmosphere has increased about 40 percent since pre-industrial times. It comes from major industries that extract and burn coal and oil, as well as tropical deforestation.

Now, climate risks are staring us in the face….

Mann reminds us that those who support climate science denialism such as Dennis Slonk, who had previously written for the Journal, insist that denialists are merely asking legitimate questions of scientists and the science. Mann then asks, if this is so, why have deniers in Congress called for criminal investigations of the scientists, and why would someone send a climate scientist a package of mysterious white powder, which, even if the powder is inert (as it turned out to be) is probably a terrorist act.

I recommend reading this Op Ed, it is quite enlightening.

Michael Mann also has an Op Ed in the Philadelphia Inquirer, HERE.

Here’s a Quiz: How Much Methane is Seeping from Old Wells?

Peter Sinclair has a post on this topic.

One is – we assume that US carbon emissions are on the downswing, and to the best of my knowledge, that’s true. However, there are some emissions that we don’t count, because they are poorly understood. These include the gentle seeping of powerful greenhouse gases from thousands of abandoned wells around the country.

So, what are we doing about this? Interesting story here.

Australian scientists announce solar energy record

AUSTRALIAN SCIENTISTS have set a new record in increasing the efficiency of solar panels, which they hope could eventually lead to cheaper sources of renewable energy.

..the researchers were able to convert more than 40 per cent of sunlight hitting the panels into electricity.

“This is the highest efficiency ever reported for sunlight conversion into electricity…We used commercial solar cells, but in a new way, so these efficiency improvements are readily accessible to the solar industry,”…

While traditional methods use a single solar cell, which limits the conversion of sunlight to electricity to about 33 per cent, the newer technology splits the sunlight across four different cells, each optimised for the fraction of the sunlight they receive, which boosts the efficiency level, Green said.

The four-way solar cells can be used at the centre of a field of mirrors which are arranged to concentrate the Sun’s rays. …

Read all about it HERE.

Hat tip: Astrostevo