Last week we were treated to the ridiculous story about Genghis Khan having an impact (or apparently not enough) with his impact on humanity. This week, a “new interpretation”; it’s the Romans and Christopher Columbus who are the ghosts of climate injustices past by daring to enable use of forest resources. I got quite the chuckle from this part, emphasis mine:
Ignoring the progress in agriculture, the preceding models implied that the same area of land is required to feed a European living in the fifth century as in the 20th century. This is why scientists struggled in trying to estimate the amount of CO2 produced by man before the industrial era. The work of Jed Kaplan’s team now enables us – for the first time – to travel back thru time.
Wow, time travel! Here is the press release in full:
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Man has been provoking climate change for thousands of years!
24.01.11 – The Roman Conquest, the Black Death and the discovery of America – by modifying the nature of the forests – have had a significant impact on the environment. These are the findings of EPFL scientists who have researched our long history of emitting carbon into the environment.
“Humans didn’t wait for the industrial revolution to provoke environment and climate change. They have been having an influence for at least 8000 years.” Jed Kaplan is putting forward a new interpretation of the history of man and his environment. This SNSF professor at EPFL and his colleague Kristen Krumhardt have developed a model that demonstrates the link between population increase and deforestation. The method enables a fairly precise estimate of human-origin carbon emissions before the advent of industrialization.
The story of our influence on the climate began with the first farmers. At that time, the prevailing technology didn’t allow an optimal use of the soil. “For each individual, it was necessary to clear a very large area of forest”, explains Jed Kaplan. However, with time, irrigation, better tools, seeds and fertilizer became more effficient. This development was a critical factor, which would partially counterbalance the increase in population, and contain the impact of human pressure on the natural environment.
Animation commented by Jed Kaplan
Agriculture – the story of a race for productivity
The relationship between population levels and agricultural land-use is therefore not simply proportional, as was formerly believed. In the Middle Ages, Europe had fewer forests than today, although since then the population has increased more than five fold. “The real innovation in our research has indeed been the taking into account of the improvements in farming techniques. Standard models simply state that the bigger the population, the more forest is cleared; but this doesn’t correspond to the historical reality.
Ignoring the progress in agriculture, the preceding models implied that the same area of land is required to feed a European living in the fifth century as in the 20th century. This is why scientists struggled in trying to estimate the amount of CO2 produced by man before the industrial era. The work of Jed Kaplan’s team now enables us – for the first time – to travel back thru time.
The influence of the Roman Empire and the Black Death on the climate
The results of this research tell a very different story from that which has been circulating up until now. They show, for example, a first major boom in carbon emissions already 2000 years before our era, corresponding to the expansion of civilizations in China and around the mediterranean.
Certain historical events, almost invisible in the preceding models, show up strongly in the data produced by the scientists. A good example is the re-growth of the forests as a consequence of the fall of the Roman Empire. The Black Death, a plague which resulted in the death of more than a third of the European population, also led to a fall in carbon emissions.
From the decline of the American indians to the minor ice age
Lastly, a significant decrease in emissions began in the 16th century – the one which would herald the minor ice age. Jed Kaplan has an audacious hypothesis to explain the dip in the data curve: “Thanks to the reports of the early explorers, we know that the forests were less abundant on the American continent. Then the settlers gradually eliminated the indigenous population.” Threatened with extinction, these populations effectively deserted the forested areas, which – by taking up the carbon in the atmosphere – in turn set off the legendary frosts of the 19th century. “Of course, it’s only a hypothesis”, he concludes, “but given the data we have gathered, it’s entirely plausible”.
Jed Kaplan’s model is not in contradiction with the previous ones on one critical point: the enormous increase in emissions from the beginning of the industrial era, and the massive use of fossil fuels. “We are just saying that our influence on the climate began a lot earlier than we thought. In 6000 BC, we were already accumulating significant quantities of carbon in the atmosphere, even though it was nothing compared to the situation today”, adds the scientist. A conclusion that could turn out to be critical in the future for the improved evaluation of the decisive impact of the forests on the climate.
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This story was released via Eurekalaert. The study authors: Prof. Jed Kaplan and Kristen Krumhardt have interesting bios.
Here’s the abstract:
Holocene carbon emissions as a result of anthropogenic land cover change
Kaplan, Jed Oliver ; Krumhardt, Kristen ; Ellis, E. C. ; Ruddiman, W. F. ; Lemmen, C. ; Goldewijk, K. K.
In: The Holocene, 2010
Date: 2010
Humans have altered the Earth’s land surface since the Paleolithic mainly by clearing woody vegetation first to improve hunting and gathering opportunities, and later to provide agricultural cropland. In the Holocene, agriculture was established on nearly all continents and led to widespread modification of terrestrial ecosystems. To quantify the role that humans played in the global carbon cycle over the Holocene, we developed a new, annually resolved inventory of anthropogenic land cover change from 8000 years ago to the beginning of large-scale industrialization (ad 1850). This inventory is based on a simple relationship between population and land use observed in several European countries over preindustrial time. Using this data set, and an alternative scenario based on the HYDE 3.1 land use data base, we forced the LPJ DGVM in a series of continuous simulations to evaluate the impacts of ALCC on terrestrial carbon storage during the preindustrial Holocene. Our model setup allowed us to quantify the importance of land degradation caused by repeated episodes of land use followed by abandonment. By 3 ka BP, cumulative carbon emissions caused by anthropogenic land cover change in our new scenario ranged between 84 and 102 Pg, translating to c. 7 ppm of atmospheric CO2. By ad 1850, emissions were 325–357 Pg in the new scenario, in contrast to 137–189 Pg when driven by HYDE. Regional events that resulted in local emissions or uptake of carbon were often balanced by contrasting patterns in other parts of the world. While we cannot close the carbon budget in the current study, simulated cumulative anthropogenic emissions over the preindustrial Holocene are consistent with the ice core record of atmospheric d13CO2 and support the hypothesis that anthropogenic activities led to the stabilization of atmospheric CO2 concentrations at a level that made the world substantially warmer than it otherwise would be.
Keyword(s): agricultural intensification, anthropogenic land cover change, dynamic global vegetation model, global carbon cycle, Holocene CO2, prehistory
Reference: EPFL-ARTICLE-161674
Full paper:
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KPO says:
January 24, 2011 at 9:27 am
During the time of Napoleon in France, they planted lots of trees, oaks mainly, because they needed them to built ships and also make drums for the whiskey, rum and of course wine. He made a law that no trees younger than 150 years old could be cut. The law was never changed. Because if that France’s area is 25% forested, twice the total of 1806.
This information comes from a whiskey company’s website.
http://www.bruichladdich.com/latestnewsarticles/16firstgrowth.htm
Jed and Kristen’s Excellent Adventure.
No Way!
Yes, Way!
The HYDE 3 database is very cool. Get ready folks because it’s being used in Ar5
Must kill all the nasty Hue-Mons and turn this into the PLANET OF THE APES!
So much for ‘renewables’
Omigawd – so the depopulated forests in America took much more CO2, which made people freeze? And that is supposed to even be ‘plausible”?
I think that ‘scientist’ has been reading too much Tolkien…
Does anyone really think that cutting down mature trees, and not replacing them, does NOT add to the amount of CO2 in the atmosphere?
You can argue what effect it had on global temperatures until the cows come home but surely everyone can agree that burning trees and not replacing them with something that ties up just as much carbon just has to add more CO2 to the mix?
And they had the audacity to breathe too.
John Blake says:
January 24, 2011 at 9:33 am
AGW catastrophists, climate hysterics, demonstrate a Thanatist psychopathology akin to Muslim terrorists’ nihilistic “death more than life” ethos of willful self-destruction.
Right on! When the Progressives = Regressives were begging and demanding that we “understand” the Islamofascists’ evil, it became obvious that they were actually inviting the rest of us to understand Them as well, in effect, as the Islamofascists’ deathworshipping groupist soul Bro’s, equally in opposition to life and the advancement of Humanity via the free-thought of the individual human mind: instead, for the “dead-ender” Progressives it is, “Give them Totalitarianism’s population control of the infidels and the plague-like masses, its suicidal-homocidalism, and its enslavement, or give them death!” CAGW “Science” is just another means toward those malignant, de-evolutionary ends.
The kneejerk viciousness of the responses here does not impress and does not reflect well on the commenters.
The theory proposed Kaplan et al. is that human impacts on the historical environment included continental-scale landscape burning. That is, anthropogenic fire drove a significant percentage of the terrestrial carbon cycle. When massive hemoclysms (human population crashes) occurred in history, the sudden dehumanization of landscapes eliminated, for a time, anthropogenic fire. During those hiatuses, plants continued to grow and carbon fixation continued apace, but CO2 emissions declined because people weren’t burning off the land so frequently or so broadly.
There are three parts to this theory. First, that historically human beings had a significant impact on the carbon cycle. Second, that a massive and rapid population crashes occurred in pre-history. Third, that the subsequent, albeit temporary, alteration of the carbon cycle (to increased fixation, decreased emissions) affected global climate.
The first two parts are cutting edge new findings in anthropology, landscape geography, and historical ecology. The evidence is strong, as are the inferences.
The third part is based on GCMs, and may be weak. Many papers here maintain that CO2 has no effect whatsoever on global climate. However, some papers by frequent posters here do so maintain, and project the sensitivity at different levels, from slight to more than slight.
[snip]
It is fair and reasonable to question the effects of CO2 on climate. As a climate realist myself, I find the CO2 theories lacking.
But it is not reasonable to deny that huge human population crashes occurred in the past.
I have read at WUWT on numerous occasions posters claiming that deforestation is rampant today, and that must be the cause of global warming, not CO2. That kind of grasping for excuses is as much pseudo-post-normal science as anything, because there are more trees per acre and more acres with trees on the planet today than at anytime during the Holocene.
The reason there are more trees today is that continental-scale anthropogenic fire has disappeared over the last 500 years. The terrestrial carbon cycle has indeed changed significantly. In western US forests the biomass loading is 5 to 10 times what it was 200 years ago, and many more times the loadings of 500 years ago when much of landscape was anthropogenic prairie and savanna, not forest at all.
Did the elimination of anthropogenic fire change the climate? I venture to say not. But I don’t deny the human-induced changes in the carbon cycle over the last 500 years.
Again, it is fair to question the effects of CO2, but it is not “skepticism” to reject whole cloth historical human influences on the environment. That’s denial.
Since Hyde 3 has land use and population going back to 10000BC it will interesting to see what difference, if any, it makes to GCM hindcasts that have land use models.
In the video they try to make us believe that except for Greenland, the rest of the land was all covered with forests. Another example of science that only shows the wanted results using deception.
What they appear to be saying is that evil man can’t live on this planet without drastically affecting it.
tonyb
Is Jed Kaplan related to Hans Christian Andersen?
This obsession with “carbon” and “greenhouse gases” is psychopathic. [snip]
As Daffy Duck would likely say… ‘this is just getting silly….’
Hey, not so fast! The ancient Greeks deforested their land turning lush mountain sides into barren rocky outcrops chopping down trees to build their ships. The Venetians deforested the Dalmatian coast to get the wood for the piles on which their city is founded. I think mankind (like every living being) has a carbon footprint existing in a dynamic interaction with the world about it. However, unlike other living beings, we can actually study the interaction and grow in understanding of our place in the world. No doubt, our attempts to study are world are coloured by our current cultural com political baggage. It’s not a good reason to fling manure (which has its own carbon footprint 🙂 ).
This is not a new idea at all. On books.google.com you can find an English book published in the early 19th century (or late 18th century) where the author claimed the climate of England was changed right after the Romans settled there and introduced agriculture. The forests were turned into fields and the climate of England went from a warmer climate that supported vineyards to the colder, damper climate they had in the 18th to 19th century.
I couldn’t find the book again or I would have provided give the link.
Re the animation: I cannot help but notice Egypt remains deep green and unchanged thoughout the run.
Also, that caveat “natural vegatation” below the map. Natural vegatation for a desert is “sparse”, yet remains colored green. Apparently “no-data” gets a green, too: Look at central Australia.
Based upon this one piece of fiction, the originator of that cartoon, Jed Kaplan, is not to be believed in any future or past work.
Louise says:
January 24, 2011 at 11:23 am
“Does anyone really think that cutting down mature trees, and not replacing them, does NOT add to the amount of CO2 in the atmosphere?
You can argue what effect it had on global temperatures until the cows come home but surely everyone can agree that burning trees and not replacing them with something that ties up just as much carbon just has to add more CO2 to the mix?”
Mature trees do not sequester carbon at nearly the rate that young trees sequester it.
If the trees are cut and used to build homes, tools, ships, wagons, etc, then it is likely a net carbon loss because, despite your assumption, trees can and do grow back without people actively planting them.
Alternatively, one could argue that when people gather firewood, esp. in primitive societies, they will gather what is easiest – dead branches on the forest floor which are slowly decomposing and releasing their CO2. Yes, burning them would speed up this process, but it may also prevent forest fires to a certain extent with clearing of flammable dead brush from the forests.
Of course, if plant life is considered good then we can wonder what the effect of killing 100 million or so large herbivores (i.e. Bison) in the 1800s. We can wonder till the buffalo come home about these things, but it is all conjecture and useless bullshit.
There they go again.
Programming their (sexual) fantasies to create a model which does what they want. This is not science!
“Lastly, a significant decrease in emissions began in the 16th century – the one which would herald the minor ice age. Jed Kaplan has an audacious hypothesis to explain the dip in the data curve: “Thanks to the reports of the early explorers, we know that the forests were less abundant on the American continent. Then the settlers gradually eliminated the indigenous population.” Threatened with extinction, these populations effectively deserted the forested areas, which – by taking up the carbon in the atmosphere – in turn set off the legendary frosts of the 19th century. “Of course, it’s only a hypothesis”, he concludes, “but given the data we have gathered, it’s entirely plausible”.”
The history of the indigenous populations of the Americas starting in 1492 is not a happy one. Disease, conquistadors (even in North America–e.g. Hernando de Soto), loss of lands to European settlers and Americans. But I’ve not read many books that posit a large, stable population through the 16th century, followed by a gradual elimination of the population (and reforestation?), that suddenly spiked somehow to bring on the Little Ice Age in the 19th century. The general theory is more like plague, war and the difficulties of enslavement carrying off multitudes (causing likely North American reforestation), followed by an increase in population, followed by encroachment of whites, who cut down forests for agriculture and wood-fire until the discovery of coal.
If this guy is looking to blame the LIA on evil Westerners, he should revise his theory and apply it to Africa. The whole slavery industry actually did depopulate vast swaths of Africa at approximately the right time. And it probably did result in reforestation since farms would have been easy targets for raiding parties. He could blame little up-and-down swings in temperature on little historical events that cause more/less agriculture. It could actually work.
This reminds me of another study that went into the past and made amazing “discoveries” about historical events and ancient history. It was called “Chariots of the Gods”. As I recall, the end result of that one was SciFi as well…
Mike D. says:
January 24, 2011 at 12:01 pm
The kneejerk viciousness of the responses here does not impress and does not reflect well on the commenters.
————–
I have been reading WUWT more or less faithfully for two years and cannot recall any – repeat, any – sceptic basing his argument that deforestation is the cause of global warming. Most of us are too well-read and aware that in North America and Europe, at least, forest extents are greater than they have been in the past 200 years (North America) or over 1000 years (Europe).
By the way, how do you distinguish between the effects of anthropogenic and natural forest fires? Since the implementation of ecosystems-based forestry in the 1980s in the US (which forbids forest clearing, and has reduced the extent of timber harvesting drastically), and anti-scrub clearing measures in Australia, forest fires, including those caused by lightning strikes, have been more extensive and damaging.
Great animation. Very interesting.