Thursday, June 3, 2010

Guest post by Vicky Slonosky: A few thoughts on the history and philosophy of anthropogenic climate change

One of the research interests of Victoria Slonosky is the analysis of long-term variability from long instrumental records and climate reconstructions. She graduated at McGill University, worked for some time at CRU. She has sent me a very interesting text, which I am glad to post here on her behalf:

This is not a post to discuss the scientific case for or against anthropogenic climate change. The past few months (or years, for some people) have been interesting not so much for any specific revelations, but because they’ve led to a re-examining of many of the arguments. There is so much vigorous debate on almost every aspect of climate change theory that it seems as if every theory, every assumption, has to be considered and tested again from first principles..

As I do this, I can’t help reflecting that we are all products of our beliefs and times, and history has shown that nearly all of our scientific beliefs eventually get overturned. A century ago, until Einstein, most scientists believed in ether; two centuries ago, before Lavoisier, many believed in phlogiston. The nature of light has gone back and forth between waves and particles for centuries, until we’ve decided, with a certain degree of exhaustion, that it’s both. Unfortunately, as Kuhn has shown, neither consensus nor, I would add, good intentions, are a guarantee in science. We can never tell which of this year’s crazy ideas will become the next decade’s working hypothesis.
The idea of anthropogenic climate change is not new, and there exists literature on this theme through history. I recently came across an early Canadian version of this theory: that forests caused cold winters, so clearing forests would improve the climate. Oddly enough, considering current discussions on the Roman Warm Period, this theory came about from the writing of the Romans. Gibbon’s descriptions of the Roman campaigns in cold and snowy forests of northern Belgium and Germany, and of Julius Caesar's military exercises on the frozen Seine, struck the early settlers as being very similar to their Canadian conditions. Since Canada is actually further south than much of western Europe, the difference in climate between them couldn’t be due to latitude, so they attributed it instead to the presence of forests. The difference between the cold and snowy winters of Roman description and the contemporary mild European winters was the evidence.

Deforestation thus became a civic duty; every tree felled not only cleared land for agriculture, but also represented an infinitesimal increase in temperature. This theory of human-induced climate change persisted, with some controversy, until the late 19th century, when it was finally, and regretfully, abandoned. It was concluded (somewhat morosely) after looking through two and a half centuries of documentary data that while there considerable variability, there was no overall change whatsoever in the onset date of spring or winter. Making a virtue out of necessity, Canadians turned their attention instead to ice hockey and tobogganing.

How would we evaluate this theory today? On the one hand, deforestation is linked to carbon emissions, which should increase the temperature, but would probably not be noticeable on a regional scale. On the other hand, the albedo of forests is lower than that of fields of grain or snow, so deforestation should have lead to winter cooling. Then there's the effect of evapotranspiration, which should have led to summer warming, but decreased cloud cover, which would lead to...we don’t know. Maybe the most curious thing about this episode is that over several centuries, large-scale deforestation had no discernible long-term effect on the regional climate.

The debate over anthropogenic climate change touches off echoes that persist through the history of Western thought: determinism vs chaos theory; nurture vs nature; free will vs fate; Plato vs Aristotle. The idea that we are causing climate change can be frightening, but it also implies we are in control; that we can decide whether to let warming continue or whether to stop it. This is an idea has always been with us (Hans has a very good overview on the history of human attempts to control the climate), starting with prehistoric weather gods. It continues with countless examples through history, with priests attempting to save Alpine villages from advancing glaciers by throwing holy water on them during the Little Ice Age, to the Canadians diligently clearing the forest in an attempt to create Montreal-sur-Seine, and on through to today. Where is dividing line between anthropogenic causes of climate change and an anthropocentric view of the world? It was interesting (and a bit troubling) that the statement that came out of Copenhagen was not to limit greenhouse gas emissions, or to limit anthropogenic climate forcing, but to limit any global temperature increase to less than 2 degrees.

All this is not to say that I think anthropogenic climate change isn’t happening or isn’t scientifically possible. We should recognize, though, that these themes are not only from the realm of science, but also form part of our (Western) philosophical and sociological background; they are part of our intellectual history. We need to be vigilant, and to be aware that our cultural background may be influencing our thinking. The scientific method of observation, deduction and independent verification is the only way we have found so far to try to step out of ourselves, of our times and beliefs. This is why the Feynmanian ideals are so central to science, and why it ‘s so important to retain a level of skepticism, debate and reproducibility. It’s what stands between us pursing a lower-carbon lifestyle and priests throwing holy water on a glacier.


Mathis Hampel said...

In my reading... the science of climate change is contingent on socio-cultural achievments (technology, political economy, institutional settings, philosophy, geography). More recently, the modelling enterprise attempts to suppress science's cultural links through predicting a glocal vision of future climatic changes. The science of climate change is yet likely to change depending on an array of(partly unforseeable)imperatives.

Georg Hoffmann said...

Hey Vicky

all that is very true, but if someone asks me about either the possibility that there will be a major Kuhn-like revolution and everything we know about climate suddenly appears in another light and is basically wrong or, alternatively, that the radiative transfer equations are rock solid not changing physics then I know where I would put my money.

If you push cultural relativism far enough you end up thinking that homoepathy actually might work, it's just a question of your "cultural background". However it doesnt work and greenhouse gases are heating planets whatever will happen in the future.

Mathis Hampel said...

Georg I also dont believe in a change in 'primitive' equations ergo the underlying physics. All we can say is that the approach to study climate change and its 'co-produced' political problem framing have changed ever since it became known that climates change. cc wont go away but our approaches, e.g., ecological modernization, may change according to the way we know cc.

Donna Laframboise said...

Thank you, Ms. Slonosky, for this thoughtful post. As a Canadian myself I would love more info about the Montreal de-forestation efforts.

Please feel free to drop me a line at: AT

Zajko said...

This reminds me of a rather common argument used by climate skeptics that goes, "in the 1970s, scientists thought we were headed towards global cooling" - thus reminding people not only that scientists can be wrong, but suggesting climate science keeps changing the story and doesn't know what it's talking about.
Kuhn does not typically enter into this argument, either because people are still unfamiliar with his insights or that the very historical argument made in this post still makes peoples' heads spin.
Kuhn would say it all comes down to a theory's ability to deal with certain scientific problems. By that standard AGW has had mixed success, but there is no alternative that has come close to doing a better job (if we were to consider natural climate variability as a theory it is a contender, but it is also an uneasy part of AGW theory).

There has been some critique of such constructivist or social/cultural takes on science as playing into the hands of climate skeptics (see Constance Lever-Tracy) but I see little evidence of this so far. Sure, many skeptics arguments can be reformulated as "AGW has been socially constructed as a problem", but they tend to leave the broader questions about the nature of science alone, often relying on the same objectivist rhetoric as those championing the reality of AGW.

I'm curious to see if the story told here will be picked up on a skeptic blog and respun for a different purpose.

Günter Heß said...

I don’t think Vicky’s argument is about basic physics like radiative transfer. It is more about secondary conclusions from basic physics in a scientific-like manner.
As an example: The hurricane rate increases if global warming occurs. If sea-level rises, Tuvalu sinks. Polar bears go to extinction, if arctic sea ice disappears. Etc.
All of this might actually occur, but it is necessary for scientists to clearly mark them as possibilities and not as a fact as long as it is not at least thoroughly validated.
Otherwise media and blogs will pick up and turn it in a mess. Since Zajko singled out skeptical blogs, I think he proves my point.
Günter Heß

Vinny Burgoo said...

Donna L, the theory and its history are discussed in Chapter 17 of _Climatology of the United States_ by Lorin Blodget, 1857, available at Google Books. Suzanne Zeller looked at its application in Canada. It seems she went into it most fully in _Inventing Canada: early Victorian science and the idea of a transcontinental nation_. I can't find an online copy of that but she touches on it very briefly in this booklet

and in a chapter in _Disseminating Darwinism_ that can be previewed at Google Books.

Other names to look out for: J H Lefroy (anti), Jefferson (pro), Humboldt (anti), Noah Webster (anti) and Marshal Marmont, the first and last Duke of Ragusa (pro).

The theory coexisted with desiccationism, but that was applied mostly in the tropics. All the same, I bet the two camps were often at each others' throats, if only because one was mostly about justifying expansionism and the other about maximising profits from what was already held. All I've been able to find is some determined questioning of Lefroy by John Roebuck, a contrarian MP (House of Commons Select Committee on the Hudson's Bay Company, 1857; available at Google Books). Some interesting parallels with modern discussions, I reckon, even if the parallels sometimes swap sides.

A choice quote from Lefroy:

[I]t therefore shows that conclusions based on data not derived from observations over a long series of years, comparable and accurate ones, are very likely to deceive us.

(Does anyone have a link to the history of human climate interventions by Hans von Storch that Vicky Slonosky mentions?)

Werner Krauss said...

Vicky Slonoki, this is really a great post, and a poetic one, too. I know some mountain folk from the Alps, and a priest throwing holy water on a glacier is even today not completely unrealistic. As I know people in the cities following a low carbon lifestyle. Today, of course, both the holy water and the lower carbon lifestyle, are practiced in order to make the glaciers stay. And both actions are, I guess, from a scientific standpoint, in vain; neither of them will have the intended effect.
Here is my question: I did not understand your final conclusion and the role you attribute to science. You write that it is important to stick to the Feynmanian ideals (?) etc:
'It’s what stands between us pursing a lower-carbon lifestyle and priests throwing holy water on a glacier.'
Could you explain in more detail how these two different forms relate to one another and to science? Somehow I don't get the point. Do you think both practices (low carbon and holy water) are opposed to science, or is lower carbon a consequence of science? Or does science lead us to a new and more appropriate way?

Werner Krauss said...

@Vinny Burgoo

I guess this is one of the articles Vicky refers too:

von Storch, H. and N. Stehr, 2006: Anthropogenic climate change - a reason for concern since the 18th century and earlier. Geogr. Ann., 88 A (2): 107–113.

You can download it here:

Vinny Burgoo said...

Thanks, Werner! That fills in a lot of gaps and corrects a few misapprehensions.