Is CO2 concentration and emergent property of Earth?

This post is an expansion of the core CO2 idea from my previous post...

I have been pondering the inexorable rise in the CO2 concentration of our planet’s atmosphere.  With the signing of the Framework Convention on Climate Change in 1992, political leaders from around the globe agreed that we should take steps to stop the increase of greenhouse gasses in our atmosphere.  Nearly 20 years later, despite many Conferences of the Parties and extensive public policy efforts, those gasses continue to accumulate.  And they continue to accumulate at roughly the same rate as when the FCCC was signed in Rio.

The usual response to this state of affairs is that we need to work harder at those approaches that have failed so far.  At some point I began wondering whether in fact our challenge is deeper: perhaps we have incorrectly diagnosed the nature of the problem.   What if the continuing emissions reflects some overarching intentionality of the Human System and hence is immune to direct public policy solutions?

A friend of mine agreed that we may have misdiagnosed, but he argued that I was giving humanity and public policy too much weight – what if increasing CO2 concentration is simply an emergent property of the Earth system?  That is, growing CO2 concentration is simply a property of the complex interactions that occur as a result of the evolution of the Earth System.

In this context, our policy efforts have been akin to a hammer looking for a nail.  If CO2 concentration is in fact an emergent property, then we will need to work at the scale of the Earth System as a whole if we are to manage GHG concentrations.  Perhaps more importantly, if this is the case, we should also be investing much more than we are in planning for life on our planet with CO2 concentrations in the 700ppm range.

Earth System Proxies

For a large project that I am working on, I have been thinking about examples of things that hold a lot of information about the state of the Earth System.  And of course I have been doing that in the context of the the diagram presented here (and whose original files are no longer available to me due to the evolution of computer software and related technologies).  The bit of the diagram that is important is the middle bit with the 3 lobes.  I gave an introduction to this diagram many years ago, and some changes have occurred, not the least is that it now shows the natural / artificial system boundary that separates bits of the Earth system that are related to human intentionality from all of the other bits (and whose continued usefulness I now wonder about).

Examples of things that might represent the state of the Earth system include things like the CO2 concentration in the atmosphere, the state of the ENSO system.  ENSO is a great example, because it has teleconnections that influence climate variability across vast swaths of the entire planet AND we can predict it to a certain extent.  This means that in a rational / logical world we should be able to use our understanding of the physics of the ocean and atmosphere to make decisions that improve the quality of human life on Earth.  Unfortunately it is not that simple, as we discovered in the mid-1990s at Columbia.

Each member of a set of such proxies would have the following qualities:

1. It would be easy to measure.
2. It would contain a great deal of information about the current state of some portion of the Earth System; and perhaps tell us something about what is likely to happen in the near future.
3. It would be more or less independent of the other members of the set (in geek speak, the members of the set would be more or less orthogonal).
4. Changes in this measure would tell us something about whether life on Earth was getting better or worse.

In the next few posts I am going to play around with some ideas for proxies in the "Life" lobe.

On the demise of the Mean

Perhaps I should call this On the demise of the Normal.  More and more these days I encounter distributions where the median is a much better descriptor than the mean.  Of course if things are distributed normally then the median and the mean (and the mode) are all the same number.  But if things are abnormal then those definitions start to point to different parts of the distribution.

My first encounter with non-normal distributions came in graduate school as I was thinking about the distribution of elevations in topographic profiles.  Turns out that those things have a lot in common with power-law distributions.  So does the distribution of sizes of earthquakes.  And all sorts of other things in nature as well.  Then of course there were arguments about the differences between log-normal distributions and power-law distributions and how you might be able to tell in which was which by measuring things.  In the context here, it doesn't matter; neither one in normal.

I have been pondering this lately because I have been trying to write about proxies for the state of the human system part of the Earth system and central tendency indictors and variability around those have come up with considerable strength.  And now I am wondering if that most archetypal of all normal distributions - heights of humans - will stand up as normal over all of Earth.  Or does that example really only work in a suburban middle class classroom in the mid-1970s.

Which in turn makes one wonder whether in fact it is the normal distribution that is abnormal...

(ain't I clever!)

Natural and Artificial

The Natural and The Artificial

Herbert Simon makes a distinction between the Natural and the Artificial that I have found useful over the years. To first cut, the Natural is everything that can be separated from human intentionality and the Artificial is that which reflects human intentionality. In more detail:

Artificial things are synthesized by humans

Artificial things may imitate appearances of natural things

Artificial things can be characterized in terms of functions, goals, adaptation

Artificial things are often discussed, particularly when they are being designed, in terms of imperatives as well as descriptives

Natural things are everything that is leftover


Over the last several decades the Artificial has encroached steadily on the Natural. It is sometimes stated that there are no ecosystems on Earth that are untouched by Human influence (indeed to the extent that those systems have plants that have physiological response to the concentration of CO2 in the atmosphere, this statement must be true). But untouched does not imply that the systems themselves are now artificial; the details of their function may be changed, but it is still independent of human intentionality. That distinction and argument is fairly straight forward in the Arctic, but what about in Manhattan?

As I have thought about the urban environmental systems, I have begun to question the usefulness of Simon's distinction in such highly engineered environments. I can not quite convince myself that the Natural has been completely swamped (after all the winds still obey the laws of fluid dynamics), but at some level it seems that the distinction has been thoroughly blurred.

Consider the trophic structure of a city. To what extent does it reflect human intentionality? The biodiversity is extremely low with a small number of very hearty species dominating the biomass. Those hearty species depend in large part on human refuse for their food. Thus we might argue that while very large parts of the urban ecosystem imitate the appearance of natural ecosystems (albeit sick ones perhaps), they are in fact synthesized by humans. The ecosystem of a city is in large part the a by product of the rest of the city's designed elements. The trophic structure of the NYC subway is an unintended consequence of the need to move a remarkably large number of people around a very small and congested environment; it trophic structure in that environment natural or artificial? In terms of imperatives, we try to destroy it constantly.

There has been a lot of discussion about whether humans are parts of the natural system. To my mind that is a question that does not have a useful answer. Humans are clearly a part of the singular Earth system, but we are a special part. We have intentionality that is of particular importance to us. So where there was a time during which humans might consider themselves apart from nature, we are now increasingly intertwined with nature despite (or perhaps because) of our efforts to isolate ourselves from the vagaries of Earth's natural systems.

Wrapping up, I think that it is important that we carry the notion of a distinction between that which reflects human intentionality and that which is independent of it, but that we also recognize that that distinction maybe coming increasingly difficult to discern. This blurring increases the importance of developing decision-making processes that recognize the potential for far reaching human impacts on Earth's functioning.