Tuesday, September 28, 2010


While looking for data comparing the amount of earth moved by human processes with that moved naturally, I came across this beautiful image and its related story. The picture shows a curl of sand and dust from the Sahara desert blowing west over Africa and across the North Atlantic before heading north at the Cape Verde islands. The Sahara contributes about half of all of the dust dumped into the atmosphere every year.

According to research reported in the New Scientist, much of this dust comes from a single valley in the Sahara and ends up fertilizing the Amazon basin.
The trees and plants in the Amazon rainforest rely on nutrient-rich dust from a single valley in the Sahara desert for sustenance, researchers have discovered.

Scientists know that millions of tonnes of mineral dust are blown from the Sahara desert to the Amazon basin each year. The dust helps keep the Brazilian rainforest soils fertile.

Now, researchers have found that 56% of this dust comes from one place: the Bodélé depression in Chad, Africa. They also showed that three times more dust than previously thought is transported each year from the Sahara to the Amazon - over 40 million tonnes.


The Bodélé valley is 200 times smaller than the Amazon basin, and forms only 0.2% of the Sahara itself. The reason the valley supplies so much dust is its location between two mountain ridges. It forms a funnel that accelerates the flow of air, not unlike a wind tunnel, allowing more dust to be carried. In winter, the valley produces an average of 700,000 tonnes of dust per day.

For more details, see Environmental Research Letters (DOI: 10.1088/1748-9326/1/1/014005)

Friday, September 24, 2010

Homer-Dixon sighting .... or, actually, hearing

Think Globally Radio recently posted an interview with Tad Homer-Dixon. As is typical of interview format shows, the topics covered are wide ranging but somewhat disconnected. If you are someone who follows his work closely, the program doesn't break any new ground. There are, however, some interesting specifics and nuances. Thus, there is the inevitable discussion of his take on events following the publication of his last book, such as the financial meltdown and the collapse of climate change negotiations at Copenhagen. More interesting to me, however, were the following:

1) An implicit call for a shift from individualist to collectivist decision making. I may be reading more into this than he intends, but beginning at the 30 minute mark of the program there is a characterization of past history in a great man framework, i.e., that major historical transformations were the product of new worldviews brought forward by charismatic leaders. He uses the World War II examples of Roosevelt and Hitler to illustrate the role of leaders taking their countries in good and bad directions respectively. He then shifts to a discussion of the need for building networks of trust and social capital, so that society can use the periods of inevitable system shock to reorganize itself in a more desirable form. Here he uses the example of the Orange Revolution and the end of apartheid. Personally, I think it is an overstatement to render the bulk of past transformations in terms of the influence of a select few. Networks, social capital and other collective processes have always been important. What has changed is the scale, character and complexity of the problems humanity currently faces. Emphasis on collective processes is more important now than in the past because the problems have exceeded the reach of our existing collective institutions and processes.

2) At the 36 minute mark, Tad defends his call for small-scale testing of geoengineering technologies. Like Dyer and others, he notes that some of the ideas are comparatively inexpensive and, should the shit really hit the fan, roughly one third the countries of the world would be financially capable of deploying such technologies in unilateral attempts to manage the global climate. To prevent the international chaos likely to irrupt if that path were taken, he advocates not only testing of the technologies (to determine which, if any, work and which don't) but intergovernmental arrangements to identify who deploys what, who pays, who is responsible if things go horribly wrong and other non-technical aspects of using geoengineering technology. As a former Boy Scout (Be Prepared!), this is a suggestion I think makes immanent sense.

3) Complexity theorists have developed a variety of different ways of conceptualizing complexity. In his earlier writing Tad opted for the 'strings of instructions' definition. There is a discussion of complexity and coupling, starting at the 7:30 mark, where he suggests that the problem with these ideas is not competing definitions and frames but, rather, an underdeveloped vocabulary for articulating the concepts themselves. He goes on to note several interesting possibilities: a) that there may be multiple forms of complexity and b) that the practical benefit of a particular level or form of complexity or coupling may be contingent on circumstances. This seems to indicate a new level of nuance and sophistication in his thinking about the concepts. A number of years ago I had a lengthy discussion with him about precisely this topic. At that point, he was heavily influenced by the debate within ecology over the relationship between ecosystem complexity and stability and argued that complexity was good (See footnote 34, Chapter 5 of the Ingenuity Gap). Similarly, he rendered Perrow's arguments (that highly complex technological systems are inherently more risky than less complex ones) as wrong. As empirical evidence of Perrow's mistake, he noted there had not been more Three Mile Islands. He was both surprised and intrigued by my suggestion that there could be multiple forms of complexity and, hence, the two arguments were not necessarily incompatible.

4) The early part of the interview revolves around the discussion of tectonic stresses developed in the first half of Up-side of Down. A longer and more coherent presentation of the book's argument is available below.

5) Beginning around the 40 minute mark the interview turns to an analysis of the cultural factors behind our attachment to economic growth. This is an interesting and useful attempt to get beyond the standard diagnosis -- that we have such an attachment and it is a problem -- to an understanding of why we have the attachment and what needs to change for us to shed the attachment. These ideas are developed further in "The Great Transformation: Climate Change as Cultural Change."

6) The interview turns to a discussion of Homer-Dixon's early work on the connection between environmental stress, scarcity and violence at the 50 minute mark. The most interesting point, around 53:30, involves a discussion of the current situation in Pakistan.

Thursday, September 23, 2010

Inequality and Cohesion

There is a long tradition in sociology, going back to Durkheim, that treats social solidarity -- the process of gluing a society together -- as fundamental. One factor in this process that gets a lot of attention is income inequality. Sociologists and economists have developed lots of different measures, the easiest to conceptualize are measures of "income share"; the percentage of national income received by a particular group (e.g., the top 10% of wage earners take home 30% of all the income).

While there is little agreement on precisely what level of difference is most appropriate (or if there is even such a thing as a single best appropriate level), there is broad agreement that tilting to the extreme in either direction can be problematic. Too little income differential and economic productivity suffers as the rewards and motivation for productivity are removed. Too much income differential and social cohesion suffers as feelings of exploitation or hopelessness spread. In an age of cheap and powerful weapons, the results can be tragic and equally disruptive to economic productivity as many countries in Latin America and Africa have discovered.

Slate contributor Timothy Noah has recently completed the fascinating series The Great Divergence, available in its entirety as a pdf file here. While the increase in income disparity within the US has been the topic of discussion for many years, the series is notable both for placing the debate in the context of a longer historical frame and for the the breadth of the research and explanations it examines.

As the above above graph shows, income disparity within the US has been increasing rapidly since the late 1970's. The difference between rich and poor is now as great as it was at the end of the Robber Baron era. More interesting to me, particularly in light of the current debate about taxes in the US, is the data below taken from the work of Princeton political scientist Larry Bartels (author of Unequal Democracy).

The graph compares the rate of income growth for individuals of different income levels during years of Republican and Democratic presidential administrations. Three things are worth noting. First, income growth at all income levels has been higher when Democrats were president (blue lines) than when Republicans were president (red lines). (Technically, the growth rates at the 95th percentile are equal, even though the graph shows higher growth for the Democrats. The difference for the 95th percentile, unlike for the others, is within the margin or error.)

Second, the length of the blue lines are roughly the same. In other words, "equal economic growth for all" seems to be a more accurate characterization of the outcome under Democrats than "economic redistribution favoring the poor." While the top percentile does do a bit worse than the rest under the Democrats, there is little difference in the rate of income growth among the bottom 80% of the population.

Third,not only does everyone do worse, but the disparities in income growth are dramatically larger during Republican administrations. The poor (20th income percentile) average only .4% income growth under Republicans, while the richest (95th percentile) see their income grow at a substantially higher rate of 1.9%.

Significantly for Canadians, this is one area where information about the US has little relevance for Canada. While poverty and inequality certainly remain issues here, the same trend toward massive increases in inequality aren't present.

For more information, see the Resilience Science post Inequality in the USA -- driven by politics? which summarizes and links to several other related works.

Tuesday, September 21, 2010

Loosely Coupled Systems

"Loosely Coupled Systems" is a concept coming back into vogue through new research on organizations and designing computer systems. It was originally developed by K. E. Weick in his research on education systems. His paper, "Educational Systems as Loosely Coupled Systems" was originally published in 1976. The article is available online here.

The following are responses to "Loosely Coupled Systems" posted on the Energy Bulletin.

Summary of the Weick paper
Keith Rollag, Babson College
In this paper Weick uses the US educational system as an example of how loosely coupled systems are both prevalent and important for organizational function. Understanding an organization as a loose coupling of actors, rewards, and technology may help better explain how organizations adapt to their environments and survive amidst uncertainties.

Weick observes that manifests of loosely coupled systems often are:
* situations where several means can produce the same result
* lack of coordination
* absence of regulations
* highly connect networks with very slow feedback times

While these manifests appear negative, they actually may help the organization by:
* allowing the organization to temporarily persist through rapid environmental fluctuations
* improving the organization's sensitivity to the environment
* allowing local adaptations and creative solutions to develop
* allow sub-system breakdown without damaging the entire organization
* allow more self-determination by actors

In general, loosely coupled systems probably are cheaper to coordinate, but are very difficult to systematically change.
(no date)

Loosely Coupled: A Term Worth Understanding
John Hagel, Viewpoint
Loosely coupled - if you’re a technology person, chances are pretty good that you are familiar with the term. If you’re a business manager, you’re probably at a loss when confronted with this term. Yet, this is a term that will reshape the business world in profound ways over the next several decades.

... A good working definition: loosely coupled is an attribute of systems, referring to an approach to designing interfaces across modules to reduce the interdependencies across modules or components – in particular, reducing the risk that changes within one module will create unanticipated changes within other modules. This approach specifically seeks to increase flexibility in adding modules, replacing modules and changing operations within individual modules. ...

Three things stand out from this definition. First, it assumes a modular approach to design. Second, it values flexibility. Third, it seeks to increase flexibility by focusing on design of interfaces.

This concept is widely practiced in computing architectures.

... But the notion of loose coupling doesn’t stop there. It also begins to reshape organizational design and behavior. Think about the organizational equivalent of component-based software or modular product design. Rather than traditional hierarchies driven by command and control management styles, we are likely to see relatively independent organizational modules brought together to perform one set of processes and then different arrangements of modules to perform other processes.
(October 9, 2002)
More on loosely connected computer systems:

Friday, September 17, 2010

Complexity and the Empire of Illusion

Chris Hedges discusses his recent book Empire of Illusion: The End of Literacy and the Triumph of Spectacle. In it he offers an updated take on the argument advanced by Neil Postman (Amusing Ourselves to Death) and Bill McKibbon (The Age of Missing Information), i.e., that modern media are fostering a set of cultural practices which are maladapted to dealing with the increasing complexity of our social and environmental problems.

This is a position that I think has some merit, but also significantly oversimplifies. The ability to deal with complex problems requires a combination of both a) deep thought, analysis and understanding of a phenomena and b) a breadth of perception and awareness in order to appreciate the wide variety and diverse nature of relevant facts and processes. Crudely put, modern media don't facilitate the first in the same way as print. But, the ability to link, connect and juxtapose ideas that aren't put together for you by the author is dramatically facilitated by new media. As such, the problem isn't the existence of new media but, rather, finding the appropriate cultural mix of the different forms. In this respect, I'm waiting expectantly for Stephen Johnson's new book, Where Good Ideas Come From.

Tuesday, September 14, 2010

The Climate Wars War

Gwen Dyer's 2008 book Climate Wars (discussed earlier on the blog both here and here) is the best known of a series of works analyzing the idea that climate change might be a trigger for social disorder, population migration and conflict. Among the others are 2003 report for the Pentagon on the national security implications of climate change; the Stern review on the economics of climate change, prepared for the UK government in 2006; and the United Nations’ post-conflict environmental assessment of Sudan in 2007, which suggested that climate change was an aggravating factor in the Darfur conflict.

But is there real proof of a link between climate change and civil war? It turns out, according to Nature News, that there is an academic war over the potential existence of such real wars.
In research published this week, he (Halvard Buhaug, a political scientist with the Peace Research Institute Oslo) finds almost no correlation between climate change indicators, such as temperature and rainfall variability, and the frequency of civil wars over the past 50 years in sub-Saharan Africa — arguably the part of the world that is socially and environmentally most vulnerable to climate change. “The primary causes of civil war are political, not environmental,” says Buhaug.

The analysis challenges a study published last year by Marshall Burke, an economist at the University of California, Berkeley, and colleagues, who reported a strong historical relationship between temperature and the incidence of civil war. They found that the likelihood of armed conflict across the continent rose by some 50% in unusually warm years between 1981 and 2002. Neither Burke nor Buhaug is giving any ground; each challenges the other’s definition of ‘civil war’ and choice of climate data sets. Given the many causes of unrest, it is not surprising that a meaningful correlation with climate is hard to pin down, says Hans Joachim Schellnhuber, director of the Potsdam Institute for Climate Impact Research in Germany.

1. Buhaug, h. Proc. Natl Acad. Sci. USA doi:10.1073/
pnas.1005739107 (2010).
2. Burke, M. B. et al. Proc. Natl Acad. Sci. USA 106,
20670–20674 (2009).

Three important points are worth noting. First, there is a substantial tradition of research dealing with the link between environmental scarcity and violence. The focus on climate change as the driver for particular types of environmental scarcity (e.g., arable land, potable water, etc.) is merely a specific twist on that earlier research.

Second, that research has also been the subject of vigorous debate. However, there are some points which emerge from the cacophony: 1) there is a relationship between environmental scarcity and violence, but the relationship is much more subtle and indirect than most people think; and 2) in contrast to the bulk of the literature which interpret their results through the lens of a particular philosophical orientation, there exist a few analytic gems such as Colin Kahl's States, Scarcity, and Civil Strife in the Developing World (reviewed here).

Third, and perhaps most significantly, both Buhaug and Burke buttress their arguments with statistical evidence gleaned from studies of a variety of historical cases. The underlying premise is that the past is prologue to the future. However, to the extent that one sees climate change as potentially involving a dramatic tipping point, that premise may not be valid.

Saturday, September 11, 2010

Tipping points and critical slowing down

Malcolm Gladwell's bestseller The Tipping Point popularized that key concept taken from complex system theory and, in particular, illustrated its significance for social systems. One of the central areas of recent research on tipping points has focused on trying to identify when they are about to occur. In other words, what changes are apparent in the system immediately before it reaches the 'tipping point', changes which could be observed and used to predict the likely onset of a system's transition to another equilibrium state?

One such phenomena has been labeled 'critical slowing down,' the decreasing rate of recovery from small disturbances to a system as it approaches a tipping point. In other words, when a system is close to a tipping point, it can take a long time to recover from even a very small disturbance. John M. Drake & Blaine D. Griffen recently reported the first experimental demonstration of such a process in a biological system "Early warning signals of extinction in deteriorating environments" (doi:10.1038/nature09389). Here is a summary of the key points from ScienceDaily:
The paper, published in the early online edition of the journal Nature, describes a study of the fluctuations in experimental populations of water fleas (Daphnia magna) undergoing environmental stress until they reach a tipping point beyond which they do not remain viable. The study is unique in its careful comparison of these stressed populations with other, healthy populations in the context of new theories about dynamic systems undergoing transitions at a tipping point. ...

The experiment featured populations of water fleas that were assigned to either deteriorating environments (in this case, declining levels of food) or stable environments (the control group). The experiment lasted for 416 days, when the last population in the deteriorating environment group became extinct. Depending upon the amount of food they received, populations in the deteriorating environment group reached the population viability tipping point after approximately 300 days. Populations in the control group never reached it; those populations persisted.

The researchers next looked at a variety of statistical indicators, early warning signals that could detect the onset of CSD and thereby predict the approach to a tipping point. They compared the indicators with the timing of the decrease in food and with the achievement of the tipping point, mathematically referred to as a "transcritical bifurcation." They found that each of the indicators -- some more strongly than others -- showed evidence of the approaching tipping point well before it was reached.

According to Drake, what is even more important is the generality such statistical indicators are expected to exhibit. That is, although precise quantitative models are required to predict most natural phenomena -- in any domain of science -- with any degree of accuracy, the theory of critical slowing down applies qualitatively anytime a bifurcation is in the vicinity. "You don't have to know the underlying equations to use the theory," Drake said, "and this is important in biology, where the dynamics are typically sufficiently complex that we often do not know which equations to use. In fact, we may never come to such a complete understanding, given the range of biodiversity out there and the fact that species are evolving all the time."

Friday, September 10, 2010

Food Riots in Mozambique

Raj Patel's analysis of the food riots in Mozambique shows how disturbances at one ecological level, here climate change, manifest on other physical, social and economic levels that actually mask the effects of climate change.

"But there’s nothing natural about the way that those weather events get transmitted around the world. The way that we experience climate change, the way that we experience global warming, is always mediated. It’s always an interaction between the natural systems and our human systems. So, for example, in Russia, the fact that there was a heat wave was compounded by the fact that Russian preparations and fire fighting equipment wasn’t very good and the preparations to actually fight the fire were inadequate. And then, of course, on top of that, Vladimir Putin announced that there would be a ban on exports of wheat to the international market. And what that did was send signals to traders and speculators in grain that, in fact, there would be less wheat available than they thought. And there were worries already about how climate will impact wheat harvests in Argentina, for example. And all of a sudden you have a sort of speculative bubble."

Contagion in natural and social systems

An interesting article on contagion in social networks was recently published in Science 329, 1194–1197 (2010). Here is how Nature summarized the findings:
A person needs contact with only one infected individual to catch a disease. But new behaviours can be harder to catch, with people often needing to have contact with several others who have adopted a behaviour before deciding to do so themselves. Damon Centola at the Massachusetts Institute of Technology in Cambridge set up an online community, instigated a behaviour — registering for an online health forum — and watched as it spread through the network.

He found that more people who were in ‘clustered’ communities (pictured right) joined the forum than people in communities with ‘random’ networks (left). This, Centola says, was because people in clusters tended to receive encouragement from several members of their social network.

Thursday, September 9, 2010

The circular fields of green are the result of pivot irrigation in the desert of Saudi Arabia. In a new study, Puma, M. J., and B. I. Cook (2010), Effects of irrigation on global climate during the 20th century, J. Geophys. Res.,
115, D16120,
it is suggested that widespread irrigation is altering local weather patterns and probably masking the effects of global warming through a process that reduces surface temperature via changes to the Bowen ratio. Just another example of how complex the climate system really is.

Tuesday, September 7, 2010

Environmentalist's Paradox

Ciara Raudsepp-Hearne and colleagues, in an article in BioScience, have posed a fundamental question: Why is average human well-being improving globally, despite resource depletion and degradation of ecosystems?

The question comes from the juxtaposition of two different data sets. On the one hand, there is good evidence, from the UN human development index (shown at the left) that the average quality of life for individuals, irrespective of where they live, has increased over the past 35 years.

On the other hand, the influential Millennium Ecosystem Assessment and a variety of other studies of the biosphere have concluded that the capacity of ecosystems to produce many services for humans is now low.

These studies are often characterized as suggesting that the humanity's ecological footprint has surpassed the carrying capacity of the biosphere. If this is the case, why is quality of life continuing to rise?

The study assesses four explanations of these divergent trends: (1) We have measured well-being incorrectly; (2) well-being is dependent on food services, which are increasing, and not on other services that are declining; (3) technology has decoupled well-being from nature; (4) time lags may lead to future declines in well-being.

The findings discount the first hypothesis, but elements of the remaining three appear plausible. A tabular summary of the findings is shown below. For better viewing, click on the figure to expand it to full screen.

The article goes on to argue that, although ecologists have convincingly documented ecological decline, science does not adequately understand the implications of this decline for human well-being. Untangling how human well-being has increased as ecosystem conditions decline is critical to guiding future management of ecosystem services. To this end, they propose four research areas to help achieve this goal: 1) how ecosystem services produce multiple aspects of human well-being, 2) ecosystem service synergies and trade-offs, 3) technology for enhancing ecosystem services, and 4) forecasting the provision of and demand for ecosystem services.

Sunday, September 5, 2010

How Much Is Left? The Limits of Earth's Resources

The September issue of Scientific American (Scientific American 303, 74 - 81 2010
doi:10.1038/scientificamerican0910-74) includes a graphically rich summary of information about the availability of natural resources and various other environmental matters. For those who don't have access to the magazine, there is also a interactive version (see below). While the information is the same, I didn't find the interface to be particularly user friendly. Yes .... the interactive version is right here. But, really, you might want to have a look at the good old print version (or its pdf cousin) :+) There are also a variety of related articles and web resources.

What's Left?Powered by Ergo:Ux

Friday, September 3, 2010

The Quadruple Squeeze on Planetary Boundaries vs Homer-Dixon's Tectonic Stresses

Johan Rockström, Executive Director of the Stockholm Resilience Centre and lead author of Planetary Boundaries: Exploring the Safe Operating Space for Humanity (which was extensively discussed in a special issue of Nature), recently gave a TED talk describing the project and its findings.

The project has two major components. The first looks at changes to the biosphere in an attempt to identify key planetary boundaries, that is "human-determined values (of key ecological variables) set at a “safe” distance from a dangerous level" such that major tipping points will be avoided and the biosphere will continue to function more or less as it currently does.

The image at the left summarizes the findings from this portion of the study: 1) the group identifies 10 key ecological variables (climate change, ocean acidification, biodiversity loss, etc. represented by the slices of the pie), 2) defines a 'safe' level for each variable (represented by the green region) and 3) compares the current measures for each variable (red regions) to the save level. The study concludes that for three variables (climate change, biodiversity loss and nitrogen cycling) we have already crossed the planetary boundary.

Second, Rockstrom argues that humanity is putting the planet into a “quadruple squeeze” through pressures of human growth and inequality, climate change, ecosystem loss, and the problem of surprise – rapid tipping points.

It is interesting to compare this analysis with that provided by Tad Homer-Dixon in The Upside of Down. Homer-Dixon contends that five "tectonic stresses" are accumulating deep underneath the surface of today's global order:
  • energy stress, especially from increasing scarcity of conventional oil;
  • economic stress from greater global economic instability and widening income gaps between rich and poor;
  • demographic stress from differentials in population growth rates between rich and poor societies and from expansion of megacities in poor societies;
  • environmental stress from worsening damage to land, water forests, and fisheries; and,
  • climate stress from changes in the composition of Earth's atmosphere.
Of the five, energy stress plays a particularly important role, because energy is humankind's master resource. When energy is scarce and costly, everything a society tries to do — including growing its food, obtaining enough fresh water, transmitting and processing information, and defending itself — becomes far harder.

The effect of the five stresses is multiplied by the rising connectivity and speed of our societies and by the escalating power of small groups to destroy things and people, including, potentially, whole cities. Interaction among the tectonic stresses and multipliers, according to Homer-Dixon, increases the possibility of unexpected and potentially catastrophic 'synchronous failure', a concept very similar to Perrow's characterization of a system accident.

Comparison shows a substantial amount of similarity in the two. With the exception of Homer-Dixon's emphasis on energy, they focus on the same factors: demographic, economic, environmental/ecological and climatic stresses and the importance of thresholds and surprise. Each, however, extends the analysis of the other in new and important directions. Thus, the Planetary Boundaries provides details on the entire range of key ecological operations necessary for viable operation of the biosphere; a topic not covered in as much detail by Homer-Dixon. Similarly, Homer-Dixon provides substantial additional insight on trends within human social systems that will affect our ability to implement the changes necessary to live within the planetary boundaries. Specifically, he adds the multipliers of globalized transportation and communication networks and the redistribution of power resulting from the proliferation of cheap weapons to the shared concern for economic inequality.

In short, the two present complementary rather than competing accounts.

Wednesday, September 1, 2010

Mea Culpa

Bjorn Lomborg has changed his tune on climate change. [The Guardian.] He's now saying that climate change is not only happening and human-induced, but that its a serious enough problem that governments worldwide should be spending $100 billion annually to counter its effects.

Bjørn Lomborg, the self-styled "sceptical environmentalist" once compared to Adolf Hitler by the UN's climate chief, is famous for attacking climate scientists, campaigners, the media and others for exaggerating the rate of global warming and its effects on humans, and the costly waste of policies to stop the problem.

But in a new book to be published next month, [Smart Solutions to Climate Change] Lomborg will call for tens of billions of dollars a year to be invested in tackling climate change. "Investing $100bn annually would mean that we could essentially resolve the climate change problem by the end of this century," the book concludes.

Examining eight methods to reduce or stop global warming, Lomborg and his fellow economists recommend pouring money into researching and developing clean energy sources such as wind, wave, solar and nuclear power, and more work on climate engineering ideas such as "cloud whitening" to reflect the sun's heat back into the outer atmosphere.