Friday, January 26, 2007

‘Wildlife-friendly farming’ versus ‘Land sparing’

I recently came across a two year old paper by four biologists published in the journal Science. Brazenly titled “Farming and the Fate of Wild Nature,” the authors less than subtlety suggest that there is a lot at stake. There is! They report that 50% of natural habitat on arable land has been cleared for agriculture, and while forests are regrowing in the developed world, deforestation continues apace in the developing world, which houses most of the world’s biodiversity. Using data from an international database of threatened birds, they also demonstrate that agriculture adversely affects biodiversity. As both population and affluence continue to rise for the foreseeable future, agriculture will continue to pose a serious threat to wilderness.

Two general strategies have been proposed to mitigate the adverse affects of agriculture:
  1. Wildlife-friendly farming – Reduced use of chemicals and planting of buffer zones may make farmland more wildlife-friendly. Supporters of organic agriculture, for example, often promote its biodiversity enhancing properties. The trade-off is lower yield, which the authors argue is a real phenomenon, citing that farmers in Europe generally do not switch to less intensive agriculture voluntarily, but are persuaded to by conversion subsidies.
  2. Land sparing – Intensive agriculture (high chemical inputs, irrigation, machinery) creates an environment harsh to most forms of life, but the high yields it generates potentially preserve wilderness that would otherwise be converted to agriculture.
The optimal strategy is not intuitively obvious. The authors put it bluntly: “Identifying the key parameters that can resolve this trade-off requires a model.” The key parameter in their model turns out to be the shape (concave or convex) of the density-yield function. A concave density-yield function means that as yield rises, the population density of a given organism initially declines slowly. Imagine a hypothetical butterfly species that persists at high population levels in undisturbed habitat, but persists at moderate density in low yield farms with buffer zones, few chemicals, etc. Conversely, a convex density-yield function says that population density initially declines precipitously with increasing yield. For the aforementioned butterfly, substitute a large tree that cannot survive at appreciable densities outside wild nature.

The authors’ primary purpose with this article is to provoke an empirical research program, not generate conclusions. Nonetheless, they tepidly support the land sparing strategy on the premise that many species, especially those of conservation concern, seem to exhibit a convex density-yield function. If correct, the results would advocate the position of the green revolution: high yield, high input agriculture is optimal both for people and the environment.

The authors anticipate three potential limitations of their approach, one of which I address here. Their model does not incorporate effects on wildlife populations on nonfarm land, a widely cited example being the dead zone in the Gulf of Mexico caused by chemical runoff from farms. Incorporating such externalities might shift the balance in favor wildlife-friendly farming. This is an important concern, but the street goes both ways. External effects of agriculture are a product of both intensity and area. Intensive farming has high external environmental costs per unit area, but they must be weighed against reduced external costs per area spread over a larger land area. For example, an abundance of low yield farms could increase habitat fragmentation.

I suspect there may be two more general criticisms that arise, not necessarily to this paper in particular, but to this approach to conservation, especially if it turns out that the convex function is more common, favoring a land sparing approach. First, a critic might claim that this is “just a model,” too abstract for the complexity of real ecosystems and overly reductionist, breaking ecosystems down into constituent species and functions. Such criticisms are wrongheaded. The real dichotomy is not abstraction/realism, reductionism/holism, but rather those who acknowledge their working models and those who do not. It is trite, but worth repeating, that our perception of the world is not an unadulterated version of sensory input. Rather, we all use models, conscious or otherwise, to make sense of reality. Mathematical models formalize this innate process and bring it the forefront of our consciousness, permitting critical evaluation. The alternative is blind surrender to our preconceptions.

Another complaint might be that the paper establishes false premises and ignores a possible third way. In particular, the small-scale, labor intensive, beyond organic, local farming movement. Relying on greater local knowledge and increased inputs of manual labor, such farms have high, sustainable yields without large inputs of chemicals or machinery. At least, that is the anecdote, as I have not seen a systematic study that bears this out. Despite the growth in local farming, it represents a small portion of total agricultural output for obvious reasons: labor is expensive compared to capital, and knowledge workers are not drawn to farm work in large numbers. Taken together, this suggests that for local farming to ever reach a broad consumer base, people must be willing to spend a lot more on food, which I doubt will occur. Improbability aside, I am skeptical, as I have expressed in earlier posts, that local farming actually has any environmental benefits over industrial agriculture.

Beyond utilitarian considerations, the wildlife-friendly farming/land sparing debate raises philosophical questions about protecting biodiversity. Though I am not that familiar with the debate, it seems reminiscent of the 19th century schism between preservationists and conservationists. The former advocated unadulterated nature for its own sake, while the latter argued that nature should be managed for human benefit. In the present context, land sparing might permit larger areas of unadulterated nature in the form of natural parks and wildlife preserves, while wildlife-friendly farming would permit land use that is beneficial to humans at minimum cost to biodiversity. I see the validity of both perspectives and do not offer a solution. Nevertheless, it is interesting how contemporary environmentalists sort out along philosophical lines. In general, those with a biological inclination lean toward wildlife-friendly farming, while developmental economists and agriculturalists advocate land sparing. I suspect divergence between the two groups arises from the duality of humanity, existing simultaneously in and above nature. Evolutionary theory shows us our place in the tree of life, while our advanced civilization has brought us out of nature. Natural scientists, steeped in evolution and ecology, may tend to perceive us as part of nature, while the social scientists, the experts on civilization, may tend to view us as outside of nature. Thus, while the former sees man as integral with and therefore capable of tinkering with his environment, the latter does not mind a clear demarcation. Bringing such cultural and philosophical differences to the forefront can promote constructive dialogue that evaluates agricultural policy not solely upon preserving biodiversity, but also on the type of nature we ultimately desire.

Monday, January 15, 2007

A bad argument against protecting polar bears

Last week, US Fish and Wildlife Service (USFWS) announced that they are considering listing polar bears (Ursus maritimus) as threatened under the Endangered Species Act. The department argues that the bears are threatened by declining sea ice, an impact of accelerated climate change in the Arctic. While their report has received mostly positive press, I have come across a common criticism that I would like to address. Critics claim that polar bears are not threatened by global warming because their current population (20-25000 spread over 19 subpopulations) is far greater than their ‘historic’ population (~5000 in the 1950’s). How could polar bears be threatened? Assuming both population estimates are correct (I believe they are), does this argument hold any water? Of course not. The intellectual dishonesty or sheer stupidity of anyone who maintains this reasoning is astounding.

Polar bears populations in the 1950’s were driven to low levels by hunting, which has been banned in the US (with the exception of native peoples*), allowing the population to rebound. However, in a species that is ~200,000 years old, the population dynamics of the past 50 years can hardly be considered historic. A proper benchmark is not the population of the 1950’s, but rather 1950 BCE!

Scientists may never know the historic population of polar bears before human intrusion, but that is actually irrelevant to the current debate. The USFWS contends that the polar bear is threatened today because global warming is causing arctic sea ice to melt, a demonstrable fact. They buttress their argument with data from polar bear surveys indicating that adult weight and cub survivorship have decreased concurrently with declining sea ice. Whether there were five thousand, five, or five million polar bears in 1950, that global warming is threatening polar bears today might still be true, as I believe it is.

To drive this point home (and get in a jab at Fox News), let me draw an analogy. I originally came across the anti-polar bear argument while watching The Big Story on Fox News, hosted by the insipid John Gibson. John Gibson has also written a book called The War on Christmas, which I haven’t read, that argues secular liberals are trying to take religion out of the holidays. By Gibson’s own logic, I could argue that the number of Christians celebrating Christmas in America is higher today than it was in the 1950’s. How could it possibly be the case that secularists are threatening Christmas? As with Gibson’s own argument, mine is a complete non sequitur, as the number of Christians in the 1950’s has absolutely nothing to do with the current “war” on Christmas.

John Gibson and his ilk are ideologues who realize that the average American, to whom they have no problem pandering their own brand of emotion laden nonsense, may see the plight of the charismatic polar bear as a convincing reason to take action on global climate change. I personally find many other cases than the polar bear more compelling reasons to mitigate climate change, but far be it for me to tell people how they should value nature. In any case, I can sympathize with the polar bears right now. Europe is experiencing an unusually warm winter, which has caused half of my study plants to begin flowering in January. Instead of a leisurely winter work schedule, I am outside from dawn until dusk bent over tiny plants. Maybe this would make for a good human-interest story on the adverse affects of climate change. Any takers?

* Native peoples may in fact not being doing enough polar bear hunting to cause any harm, but I find this to be an unwarranted exception in name of cultural relativism. As with female genial mutilation, there are some cultural practices that are simply beyond the pale of contemporary morality, and I find hunting polar bears to be one of them. As we ask the rest of our citizens to desist from hunting threatened species, so should we of native peoples.

Sunday, January 14, 2007

Jagdish Bhagwati on Globalization

I recently finished Columbia economist Jagdish Bhagwati's book In Denfense of Globalization, in which he argues that global economic integration (free trade, foreign direct investment, and free movement of capital) alleviates poverty, reduces global inequality, enhances rights, and does not harm, and may actually improve, environmental quality. I won't review the book because it's time consuming, and I have addressed some related ideas in a previous post. I will briefly summarize his points on globalization and the environment, but mostly I wanted to share a passage that caught my attention.

On globalization and the environment, Bhagwati argues:
  1. Multinationals generally have higher, not lower, environmental standards compared to their domestic counterparts. Firms do not generally have vastly different modes of production from country to country. Consequently, if a firm has factories in six countries with varying environmental standards, all six tend to resemble the factory located in the country with the highest standards.
  2. While theoretically possible, there is no evidence for a race to the bottom on environmental standards. That is, countries do not lower their standards in response to firms relocating abroad. In fact, there appears to be, if anything, a race to the top, as developing countries are adopting higher environmental standards as their incomes rise.
  3. The WTO should not make environmental standards a part of free trade deals. First of all, the WTO is small organization whose mission is to foster economic integration, not regulate the environment, labor, and so forth. Secondly, it would not be advisable to "level of the playing field" before trade can occur. Trade functions on differences between countries, including varying tolerance of pollution. Bhagwati offers a provocative example: the US has not signed the Kyoto treaty. Should the rest of world be able to place tariffs on all US goods that require energy? Right or wrong, our decision not sign Kyoto reflects the wishes of our elected government. Likewise, if the people of Cambodia decide they can withstand slightly more mercury in their drinking water than, say, the Netherlands, that is not a reason for the Dutch to place tariffs on Cambodian goods. Finally, barriers to trade are an inefficient way to achieve higher environmental standards. Rather than lobbying the WTO, civil society groups concerned with should work with international environmental agencies and developing country governments to adopt higher standards that meet the needs of local citizens and global environmental problems.
Below is a passage I liked. It reminds me of my own naivete coming out of high school, and how my view of the world has been enriched by critical thinking. Enjoy!
“The very young care intensely for the environment. They rarely think in terms of trade-offs, implicitly ignoring the cost of reaching environmental goals and therefore never having to revise environmental preferences in the light of knowledge about the cost of indulging them. They have an oversimplified view of what must be done. They get upset when, confronting their parents and asking for cloth diapers to be chosen in preference to disposables, they are told that cloth diapers are likely to be washed in detergents and that, if you go yet further back in the chain of inputs, it is possible that a shift to cloth diapers may cause net environmental harm. And they are not alone: several environmental activists get agitated as well by they call “obfuscation,” which any systematic and comprehensive analysis often leads to. And that is precisely, of course, what economists bring to the table. I recall one of my Oxford teachers, Ian Little, a world-class economist, telling me when he had returned from a couple of years advising in Whitehall 'I thought we economists worked with models that sometimes abstracted too much from complexity. But I found that bureaucrats and politicians worked with even simpler, na├»ve models: if x affected y, that was the end of the matter; whereas the economists typically argued, ‘But y will affect z, which in turn will affect x and feed back on y as well.' In fact, the iconoclastic New York Times columnist John Tierney once told me that the greatest amount of condemnatory e-mail he had received was over a New York Times Magazine article showing how recycling programs had actually worsened the garbage problem.”

Thursday, January 04, 2007

Unrelated Note: Regean used astrology?

Just came across this bit of old news. Apparently, astrologist Joan Quigley was quite influential in the Reagan administration. One of her major "accomplishments" was linking Reagan's assassination with that of Lincoln, since they were both born in February and were elected in a year that ended with zero. Incidentally, the chance of that happening is one in sixty, which is not particularly astounding, especially given all the astrological dissimilarities that she almost assuredly forgets to mention. Anyway, my point is not to insult Quigley - astrology is clearly an enormous load of bullshit - but simply to express how astounded and disgusted I am to learn that a president would seek advice from an astrologist as late as the 1980's! Of course, all the politicians like Bush who regularly council from their magic friend Jesus are no better. Anyway, the point is that the American people need to double check to make sure their elected officials are using reality as their guide.