The Natural Patriot

I know, I used the same subtitle for another recent post.  But I’m not recycling titles out of laziness — well, not entirely anyway. I do so here to highlight the simple, yet perversely (and perhaps intentionally) misunderstood theme whose centrality to the broad range of environmental problems is increasingly obvious.  Hence the “stupid” bit. 

The simple, central, misunderstood theme is this: Despite the rosy optimism one hears from various quarters, We can’t grow our way out of our environmental problems. Yes, of course technology can help, and we need creative entrepeneurship.  But blind reliance on the “free” market is not going to do the trick. 

The latest evidence on this front comes from an analysis, across 102 countries, of the impacts of human population density, urbanization, and economic growth on the condition of marine biological communities.  Rebecca Clausen and Richard York set out to quantify the role of changing human social development and economic institutions in the accelerating decline of marine biological diversity.  It’s well-recognized that human impact on the environment is ultimately a result of demographic and economic factors. But there is disagreement about how these processes affect the environment.  Indeed, as they note:

“Neoclassical economists argue that environmental quality is a luxury good and, therefore, only affluent societies are willing to heavily invest in environmental protection. The environmental Kuznets curve (EKC) describes this hypothetical relationship between affluence and environmental quality. The EKC hypothesis suggests that environmental problems escalate in the early stages of economic development, but eventually a tipping point is reached, after which further economic growth leads to improvements in environmental quality.” 

In other words, the argument goes, once you get to be as rich as the United States, it’s all good.  The idea is that affluence leads to better resource and environmental management.  For example, we often hear that concern over global overfishing is alarmist because we have (some) good fishery management practices in effect in civilized places like the USA, Canada, and New Zealand. Though the latter bit is true, it’s not clear that such practices are becoming more widespread in time or space. 

In fact, there is considerable evidence against the hypothesis that economic development improves environmental quality on anything more than a local scale.  But the aim of this paper was to test the EKC hypothesis broadly, by considering diverse marine ecosystems rather than single fished species or stocks.  As an indicator of marine biodiversity they used the “mean trophic level” of fisheries catches between 1960 and 2003.  The basic rationale here is twofold.  First, mean trophic level roughly estimates the proportion of the catch that is made up of big top predators (tunas, cod, etc.), compared with, say, anchovies, and the abundance of top predators is in turn a good indicator of the degree to which the ecosystem supports a taxonomically and functionally diverse biological community.  Second, fishing tends to target top predators, so the decline in mean trophic level signals increasing human impact.  Indeed, the targeting of top predators is consistent enough that Daniel Pauly and colleagues famously summarized the succession of industrial fishing impacts as “fishing down the food web” (see the figure). 

Clausen and York developed mathematical models to capture the effects on mean trophic level of human population, per capita GDP, degree of urbanization (% of population living in urban areas).  The model included various terms to account for changes in marine productivity, geographic expansion of fisheries, changes in fishing effort, and so on.

What they found is important, if not terribly surprising.  First of all, at the risk of stating the obvious, countries with higher populations, urbanization, and economic growth caught more fish.  Overall, the healthy structure of marine ecosystems, as indexed by mean trophic level of catch, declined as economic growth, urbanization, and human population size increased. 

But there were some interesting twists with respect to the EKC hypothesis.  For example, fishery catch roughly matched the EKC predictions, dramatically increasing with per capita GDP during early stages of economic development, reaching a plateau at ~ US $3000, then declining modestly.  Urbanization, however, showed a pattern opposite to that predicted by EKC:  fish catch by a country initially declined with urbanization, then increased again after ~36% of the population was living in cities.   Importantly, “the total effect of GDP per capita [on MTL] was monotonically negative”, meaning roughly that as average individual income increased, the abundance of predators in that country’s exclusive economic zone declined (see graph at left).  This effect was strongest during early stages of economic development. On the bright side, growth in per capita GDP above $10,000 had little effect on mean trophic level of catches.

Long story short - “Our results contradicted both the economic and urbanization EKC hypotheses, indicating that economic development and urbanization led to marine biodiversity loss. Likewise, population growth clearly led to depletion of marine fisheries.” From a policy perspective, the take-home message is the “grow-your-way-out-of-your-problems” economic theory championed by the likes of Julian Simon and Bjorn Lomberg doesn’t work, at least fr marine fisheries and ecosystem health. 

One might be forgiven for thinking this would be common sense.  How can building more buildings and roads and ships and airplanes and iPods and vacuuming up the earth’s living and nonliving resources to fuel it all reduce our impact on the environment? The simple fact is: it can’t.  Alas, that sense is not in fact common, at least not in mainstream economic theory, which of course is the philosophical guiding light of modern civilization.  Fortunately, there is growing recognition that the physical basis on which the economy is built is finite, and that a sustainable future will require a steady-state economy.

Now, I don’t want to be misunderstood, since I know certain readers may jump to conclusions here. Obviously, economic development is important, and people need food, of which marine fish are a very important source worldwide and will continue to be.  It would be silly to think that we can or even should stop fishing.  But this and a growing body of other evidence are making it clear that humanity will have to manage marine fisheries and other interactions with the environment much more thoughtfully than we have done if we expect our grandkids to be enjoying them too.  Pretending that “free”-market economics alone will magically solve such problems is a fantasy.

[Original source: Clausen, R. and R. York. 2007. Economic Growth and Marine Biodiversity: Influence of Human Social Structure on Decline of Marine Trophic Levels. Conservation Biology doi:10.1111/j.1523-1739.2007.00851.x]