I found this interesting-looking book on Amazon today:

It’s about why you can’t predict natural systems. There’s some info from the publisher below, and a link to a review in the NY Times:

PUBLISHER: Noted coastal geologist Orrin Pilkey and environmental scientist Linda Pilkey-Jarvis show that the quantitative mathematical models policy makers and government administrators use to form environmental policies are seriously flawed. Based on unrealistic and sometimes false assumptions, these models often yield answers that support unwise policies.

Writing for the general, nonmathematician reader and using examples from throughout the environmental sciences, Pilkey and Pilkey-Jarvis show how unquestioned faith in mathematical models can blind us to the hard data and sound judgment of experienced scientific fieldwork. They begin with a riveting account of the extinction of the North Atlantic cod on the Grand Banks of Canada. Next they engage in a general discussion of the limitations of many models across a broad array of crucial environmental subjects.

The book offers fascinating case studies depicting how the seductiveness of quantitative models has led to unmanageable nuclear waste disposal practices, poisoned mining sites, unjustifiable faith in predicted sea level rise rates, bad predictions of future shoreline erosion rates, overoptimistic cost estimates of artificial beaches, and a host of other thorny problems. The authors demonstrate how many modelers have been reckless, employing fudge factors to assure “correct” answers and caring little if their models actually worked.

A timely and urgent book written in an engaging style, Useless Arithmetic evaluates the assumptions behind models, the nature of the field data, and the dialogue between modelers and their “customers.”

A new report from the World Wildlife Fund warns of overshoot, but also shows how we can once again live within the earth’s biocapacity. Called the Living Planet Report 2006, the authors provide even more impetus for a managed energy descent before it is too late.

Reading the report brings to mind Catton’s seminal work Overshoot, as it uses much of the same terminology, and conveys essentially the same message. It also backs up many of Catton’s initial arguments with hard data, making this reviewer wonder “if only we’d listened back then…”. But of course we didn’t, and one can also say that about a myriad of other issues as well - so on we go.

The report calculates the ecological footprint and biocapacity for around 150 countries in an extensive series of tables, and also provides many graphics about ecosystem health (or otherwise).

The part of the report that I would most like to focus on is their scenario analysis. They identify three different possible futures for us - business as usual, a slow-shift to essentially bioequilibrium, and a rapid overshoot-reduction scenario - and calculate the outcomes until the end of this century.

Scenario 1 (Business-as-usual)
Based on what the authors say is a fairly modest business-as-usual scenario, the accrued amount of ecological “debt” is equivalent to 34 years of the planet’s entire bioproductivity.

Scenario 2 (Slow-shift)
This scenario brings humanity out of overshoot by 2080. The authors make the point that even though most renewable energy sources reduce carbon dioxide emissions, they increase the demand on land. They also say that “the challenge is to increase energy supply whilst reducing carbon dioxide emissions, without shifting the burden on to other parts of the biosphere”. I wish I’d thought of that.

Scenario 3 (Rapid-reduction)
This scenario is the only one that will get us out of trouble, as it moves us out of overshoot by 2050. It also preserves 30% of biosphere capacity for wild species by 2100. It illustrates that we must invest in our future - it has the greatest up-front cost but carries the least risk for humanity.

General considerations
Global carrying capacity can be irreversibly decreased by ecosystem disruption (eg loss of biodiversity, habitat disruption, soil erosion, overfishing).

Decreasing our ecological footprint is an essential part of ending overshoot.

The faster overshoot ends, the lower the risk of irreversible ecosystem damage.

Previous examples of societal collapse due to local or regional overshoot (see for example Diamond’s Collapse) is a preview of what could happen on a global scale.

If we are to avoid this pattern on a global scale, the relevant question may not be what it would cost to eliminate overshoot, but what it would cost not to.

Any strategy involving large groups of people or long-lived infrastructure (like bridges or dams) have slow response times (due to long lifespans). A corollary is that the people born now and the infrastructure built now shapes resource for many decades ahead:

The longer infrastructure is designed to last, the more critical it is to ensure that we are not building a destructive legacy (by requiring a large ecological / energy footprint for operation and maintenance).

One type of ecological “asset” cannot be substituted for another (unlike classical economic assets).

An expansion of this idea is that exhausting one system’s “assets” puts more pressure on another system (eg exhausting fish stocks puts more pressure on the soil to produce the equivalent amount of protein).

Conclusion
The authors conclude by saying that we essentially need a major shift in thinking if we are to break free of materialism, as it is “only in this way that we can once again (live) within the biological capacity of the planet”. They also provide a suggested problem-solving process based on systems thinking and continual improvement (see figure).

Further Reading (from the report)
The Weather Makers (Flannery)
The Future of Life (Wilson)

Other suggested books (from the Footprint Network)
World Atlas of Biodiversity

Related Links
WWF International
Institute of Zoology
Global Footprint Network

Any comments?