Tag Archives: ecology

RIO+20 Talks Need to Consider Physical Limits

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RIO+20, the United Nations Conference on Sustainable Development, is to be held this week on June 20-22 in Rio de Janeiro.

The term Sustainable Development seems to me to be almost a contradiction in terms. One dictionary gives the definition of “development” as “the act or process of developing; growth; progress”. In a finite world, how can growth be sustainable? Isn’t it possible that human population already passed the world’s carrying capacity, and world leaders should be talking about shrinking instead of growing?

The open access journal PLoS Biology is starting to raise questions in this area. According to a press release of the journal, “Coinciding with Rio+20, the open-access journal PLoS Biology is publishing three articles in the June 19 issue by leaders in ecology and conservation science who raise important concerns about physical limits on resource use that should be considered at the conference—but almost certainly won’t be, because sustainability has largely developed with little reference to the key ecological principles that govern life on Earth.”

I’d like to highlight one of these articles called, “The Macroecology of Sustainability“. The article is by Robbie Burger and Jim Brown at the University of New Mexico, plus several other authors. I mentioned this upcoming article in March in my post True Sustainability Solutions.

The “Macroecology of Sustainability” points out that the discipline of sustainability science, as it is usually practiced, tends to be a social science rather than a natural science.  Studies are often at a local scale, rather than a global scale, and focus on efforts to improve standards or living and reduce environmental impacts, without consideration as to whether these so-called solutions would be feasible on a global scale. According to the researchers, “Any efforts to develop a science of sustainability or implement policy solutions are necessarily incomplete and will ultimately fail without considering the core ecological principles that govern all of life.”

This is a link to the entire current issue of PLoS Biology, including the three articles.

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True sustainability solutions

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We live in a world with very limited solutions to our sustainability problems. I often hear the view, “If we would just get off fossil fuels, then our society would be sustainable.” Or, “If the price of oil would just go high enough, then renewables would become economic, and our economy would be sustainable.”

Unfortunately, our problems with sustainability began a long time before fossil fuels came around, and the views above represent an incomplete understanding of our predicament. When fossil fuels became available, they were a solution to other sustainability problems–rapid deforestation and difficulty feeding the population at that time. Getting rid of fossil fuels would likely lead to very rapid deforestation and many people dying of lack of water or food. If getting rid of fossil fuels is a solution to our predicament, it is one with very bad side effects.

A couple of different events this week reminded me about how deeply embedded our sustainability problems are. For one, I had the opportunity to read a draft of a soon-to-be published paper by James H. Brown and a group of others from the University of New Mexico and the Sante Fe Institute called, “The Macroecology of Sustainability.” This paper points out that sustainability science has developed largely independently from and with little reference to key ecological principles that govern life on earth. Instead, sustainability science is often more of a social science, looking at slightly greener approaches which are almost as unsustainable as the approaches they replace.

A second thing that reminded me of our long-term problems with sustainability was a pair of articles in this week’s issue of Science. There is a research article called, The Aftermath of Megafaunal Extinction: Ecosystem Transformation in Pleistocene Australia by S. Rule et al, and an accompanying perspective article called The Hunters Did It by M. McGlone.  The perspective article explains that there had been a controversy as to why marked changes in habitat took place shortly after humans settled Australia. Some thought that the loss of forest and animal extinctions were the result of climate change. New research shows that the changes almost certainly came from hunting and the use of fire by humans. This is further evidence that humans did not live sustainably, even when they were still hunters and gatherers. (See my earlier posts, European Debt Crisis and Sustainability and Human population overshoot–what went wrong?)

Below the fold, I will offer some ideas about truly sustainable solutions. Continue reading →

Human population overshoot–what went wrong?

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There are seven billion people on earth now. I originally thought that the primary reason for the recent human population explosion was that fossil fuels enabled a larger food supply and better medicine, and thus a higher population.

Figure 1. World population from US Census Bureau, overlaid with fossil fuel use (red) by Vaclav Smil from Energy Transitions: History, Requirements, Prospects.

While the addition of fossil fuels is part of the story, after reading Craig Dilworth’s Too Smart for Our Own Good: The Ecological Predicament of Mankind, I realized that there might be another contributing factor. Animals of all types (presumably including humans) have instincts and learned behaviors that prevent population from rising without limit.

Dilworth talks about an experiment in which a few Norway rats were put into a cage of 1,000 square meters and provided plenty of food and water for 28 months. If they had produced as many offspring as theoretically possible, there would have been 50,000 of them at the end of experiment. If they had maxed out at the 0.2 m2 allowed for caged rates in laboratories, there would have been 5,000 of them. What actually happened is that the population stabilized at less than 200.

As I read about the mechanisms for keeping the population of most animals down, it struck me that there seem to be parallels in humans. Dilworth talks about many species being “territorial,” and how aggression among groups is one of the first approaches to keeping population down. When that fails (as with humans’ globalization), social power structures and hierarchies become more important. This seems to happen with humans also:

Paul Buchheit, from DePaul University, revealed, “From 1980 to 2006 the richest 1% of America tripled their after-tax percentage of our nation’s total income, while the bottom 90% have seen their share drop over 20%.” Robert Freeman added, “Between 2002 and 2006, it was even worse: an astounding three-quarters of all the economy’s growth was captured by the top 1%.”

This sounds exactly like the kind of hierarchical behavior observed in the animal kingdom when social species get stressed. If there is not enough to go around, resources that are available are concentrated in the hands of those at the top of the pyramid, marginalizing those at the bottom of the pyramid. If total resources are inadequate,  population at the bottom of the pyramid is reduced, leaving those at the top untouched.

In this post, I discuss some of the issues raised by Dilworth  and the parallels I see with humans. I also add a perspective of hope. Continue reading →