Ecotourism and poverty

This is a hard problem to answer well, but its certainly an interesting question.

Quantifying causal mechanisms to determine how protected areas affect poverty through changes in ecosystem services and infrastructure
Paul J. Ferraroa and Merlin M. Hanauer

Abstract: To develop effective environmental policies, we must understand the mechanisms through which the policies affect social and envi- ronmental outcomes. Unfortunately, empirical evidence about these mechanisms is limited, and little guidance for quantifying them exists. We develop an approach to quantifying the mechanisms through which protected areas affect poverty. We focus on three mechanisms: changes in tourism and recreational services; changes in infrastructure in the form of road networks, health clinics, and schools; and changes in regulating and provisioning ecosystem services and foregone production activities that arise from land- use restrictions. The contributions of ecotourism and other ecosys- tem services to poverty alleviation in the context of a real environ- mental program have not yet been empirically estimated. Nearly two-thirds of the poverty reduction associated with the establish- ment of Costa Rican protected areas is causally attributable to opportunities afforded by tourism. Although protected areas reduced deforestation and increased regrowth, these land cover changes neither reduced nor exacerbated poverty, on average. Protected areas did not, on average, affect our measures of in- frastructure and thus did not contribute to poverty reduction through this mechanism. We attribute the remaining poverty reduction to unobserved dimensions of our mechanisms or to other mecha- nisms. Our study empirically estimates previously unidentified contributions of ecotourism and other ecosystem services to pov- erty alleviation in the context of a real environmental program. We demonstrate that, with existing data and appropriate empiri- cal methods, conservation scientists and policymakers can begin to elucidate the mechanisms through which ecosystem conservation programs affect human welfare.

Pricing the clathrate gun hypothesis

In this week's Nature:

We calculate that the costs of a melting Arctic will be huge, because the region is pivotal to the functioning of Earth systems such as oceans and the climate. The release of methane from thawing permafrost beneath the East Siberian Sea, off northern Russia, alone comes with an average global price tag of $60 trillion in the absence of mitigating action — a figure comparable to the size of the world economy in 2012 (about $70 trillion). The total cost of Arctic change will be much higher. Much of the cost will be borne by developing countries, which will face extreme weather, poorer health and lower agricultural production as Arctic warming affects climate. All nations will be affected, not just those in the far north, and all should be concerned about changes occurring in this region. More modelling is needed to understand which regions and parts of the world economy will be most vulnerable.

Wikipedia on the clathrate gun hypothesis here. For scale, Costanza et al. calculated the annual value of the world's ecosystem services in 1997 at $16-54 trillion, or $23-79 trillion in today's dollars.

Human socio-economics predict elephant population better than elephant habitat

Understanding spatial differences in African elephant densities and occurrence, a continent-wide analysis
Willem F. de Boer, Frank van Langevelde, Herbert H.T. Prins, Peter C. de Ruiter, Julian Blanc, Marc J.P. Vis, Kevin J. Gaston, Iain Douglas Hamilton

The densities and survival of many wild animals are presently at risk. Crucial for improving conservation actions is an understanding on a large scale of the relative importance of human and ecological factors in determining the distribution and densities of species. However, even for such charismatic species as the African elephant (Loxodonta africana), spatially explicit, large-scale analyses are lacking, although various local-scale studies are available. Here we show through continent-scale analysis that ecological factors, such as food availability, are correlated with the presence of elephants, but human factors are better pre- dictors of elephant population densities where elephants are present. These densities strongly correlate with conservation policy, literacy rate, corruption and economic welfare, and associate less with the availability of food or water for these animals. Our results suggest that conservation strategies should be organized in a socioeconomic context. The successful conservation of large animal species could depend more on good human education, greater literacy, good governance, and less corruption, than merely setting aside areas for conservation.

h/t Nitin

Nature on Rio+20

Johannes points out that Nature is running a special issue on the environment in honor of Rio +20. Of special interest is the following by Barnosky et al.:

Approaching a state shift in Earth’s biosphere 

Localized ecological systems are known to shift abruptly and irreversibly from one state to another when they are forced across critical thresholds. Here we review evidence that the global ecosystem as a whole can react in the same way and is approaching a planetary-scale critical transition as a result of human influence. The plausibility of a planetary-scale ‘tipping point’ highlights the need to improve biological forecasting by detecting early warning signs of critical transitions on global as well as local scales, and by detecting feedbacks that promote such transitions. It is also necessary to address root causes of how humans are forcing biological changes.

There's a nice discussion article over at the NY Times' Green blog:

In interviews, scientists involved in writing the paper acknowledged that the 50 percent threshold was simply a best guess, based on extrapolating the earlier research. But they said they were deeply concerned about many of the trends on the planet and the seeming inability of the world’s political leadership to grapple with them. 

The situation “scares the hell out of me,” said one author of the paper, James H. Brown, who is a macroecologist at the University of New Mexico and a member of the National Academy of Sciences. “We’ve created this enormous bubble of population and economy. If you try to get the good data and do the arithmetic, it’s just unsustainable. It’s either got to be deflated gently, or it’s going to burst.”

These sorts of articles come out sufficiently frequently that I think we may need to call in some science historians to do a lit review of eschatology in ecology...

Was there a trend break when Noah built his Ark?

I just sifted through a 700-entry bibliography, and this was the coolest paper I found (2008, PNAS). It definitely wins the FE-paper-find-of-the-month award.  I don't have the patience to carefully track population changes in rodent communities for 30 years (!), but I'm really excited to see the results when someone else does.

Impact of an extreme climatic event on community assembly
Katherine M. Thibault and James H. Brown

Abstract: Extreme climatic events are predicted to increase in frequency and magnitude, but their ecological impacts are poorly understood. Such events are large, infrequent, stochastic perturbations that can change the outcome of entrained ecological processes. Here we show how an extreme flood event affected a desert rodent community that has been monitored for 30 years. The flood (i) caused catastrophic, species-specific mortality; (ii) eliminated the incumbency advantage of previously dominant species; (iii) reset long-term population and community trends; (iv) interacted with competitive and metapopulation dynamics; and (v) resulted in rapid, wholesale reorganization of the community. This and a previous extreme rainfall event were punctuational perturbations—they caused large, rapid population- and community-level changes that were superimposed on a background of more gradual trends driven by climate and vegetation change. Captured by chance through long-term monitoring, the impacts of such large, infrequent events provide unique insights into the processes that structure ecological communities.

I know unsustainable development when I see it

People frequently ask "What is sustainable development?"  That's a hard question to answer well at a cocktail party.  But the reverse is much easier to handle: "What is unsustainable development?"  Stealing from Justice Potter Stewart's definition of pornography, I can confidently say "I know it when I see it."  Here are two interesting examples that I recently found in the literature.

Buffalo Hunt: International Trade and the Virtual Extinction of the North American Bison
M. Scott Taylor

Abstract: In the sixteenth century, North America contained 25 to 30 million buffalo; by the late nineteenth century fewer than 100 remained. While removing the buffalo east of the Mississippi took over 100 years, the remaining 10 to 15 million buffalo on the Great Plains were killed in a punctuated slaughter lasting little more than ten years. I employ theory, international trade statistics, and first-per- son accounts to argue the slaughter was initiated by a foreign-made innovation and fueled by a foreign demand for industrial leather. European demand and American policy failure are jointly responsible for the “Slaughter on the Plains.”

(h/t Ram)


ON THE COLLAPSE OF HISTORICAL CIVILIZATIONS 
DAVID H. GOOD AND RAFAEL REUVENY

To explain the collapse of historical civilizations, scholars typically point to suboptimal behaviors including misunderstanding the natural environment, shortsightedness, or a lack of institutions. We examine the collapse of four historical societies with a model of endogenous population growth and renewable resources employing components of optimal resource management, economic growth theory, and the moral philosophy of social welfare function choice. We find that these collapses may have been socially optimal. Further, we show that the transient behavior of the system is more sensitive to assumptions than the equilibrium behavior and that focusing solely on equilibria may miss key insights.

[a related but different view is here]

How important is brain temperature? Ask a large predator fish

This is the kind of thing I can't believe they didn't teach me in elementary school.  I knew the platypus was exceptional among mammals for its beak and eggs, but I never knew that some cold-blooded animals (ectotherms) were actually partially warm-blooded (regional endothermy is the technical name). 

I was doing a literature review of the effects of temperature on brain function and cognition, when I ran across this amazing literature. In a famous 1982 Science article, Francis Carey of WHOI demonstrated that swordfish had evolved a specialized organ that simply sat next to their brain and kept it warm by burning calories quickly.  This was important, he argued, because these fish rapidly dove to depths where the water temperature was 20 degrees (C) colder than their normal environment. Because brain function is important to these hunters, it seemed reasonable that it was worth it for them to evolve specialized organs to keep their brains warm.

Sound too fantastic? Since then, cranial endothermy has also been documented in some varieties of sharks and tuna.  Because these species are so far from one another (in an evolutionary sense) and many of their more closely related relatives didn't have brain heaters, its thought that these different groups evolved similar organs independently from one another. This would suggest that maintaining a relatively more stable brain temperature might have large benefits.  Now, does this apply to humans?...

Urban ecology doesn't care about your locavore agenda

I'm not sure how well this comes through on the blog, but Sol and I (and, I think it's safe to say, many if not most of the people in our program) have fairly nuanced views on the subjects that people normally associate with "sustainability." Green architecture, recycling, organic foods, hybrid cars, and a host of other topics that spring to mind when someone mentions sustainability tend to be partial solutions to complex problems, and the ways in which they interrelate and sometimes even interfere with each other can be very difficult to disentangle. A really lovely example of this comes from today's NY Times article about urban beekeepers' honey turning red:

Where there should have been a touch of gentle amber showing through the membrane of their honey stomachs was instead a garish bright red. The honeycombs, too, were an alarming shade of Robitussin.

“I thought maybe it was coming from some kind of weird tree, maybe a sumac,” said Ms. Mayo, who tends seven hives for Added Value, an education nonprofit in Red Hook. “We were at a loss.”

An acquaintance, only joking, suggested the unthinkable: Maybe the bees were hitting the juice — maraschino cherry juice, that sweet, sticky stuff sloshing around vats at Dell’s Maraschino Cherries Company over on Dikeman Street in Red Hook.**

I think this a really lovely illustration of how the ways in which we like to conceptualize "doing the right thing" and "acting sustainably" are often based on very tenuous understandings of how science and complex systems actually work. Proponents of eating locally make many claims about its benefits that are often unproven, or difficult to test, or sometimes even known ex-ante to be false. That's not to say that eating locally is not a good thing; it's to say that the answer to that question is complicated and depends on factors that vary with geography, the food in question, what you consider to be 'local,' etc.

Which is why this is such an interesting little article. Urban apiculture has become very popular of late and, I'd say, is probably on bar a pretty good thing; the value from having more pollinators around alone is probably fairly high, and if people are getting good honey out of it all the better. But pursuing local food as a sort of monolithic good is bound to fail, sometimes in predictable ways like the disconnect between local net primary productive potential and local demand, and sometimes in unpredictable ways such as having your honey turn up shades of Red Dye No. 40. Food production is inextricably and definably a part of the local ecology, and when your local ecology is urban that means you're going to end up with different outcomes than out in farmland.

So, if this post were to have a moral (and not to pick on these beekeepers because, like I said, I think urban apiaries are pretty net beneficial), it's this: don't take as received wisdom what those around you claim is "sustainable"; don't claim that the solution to a sustainability problem you've currently settled on is fool-proof or even the right one; and internalize the fact that the world is a complex place and thus anyone who claims they've figured out an answer to a major problem and are "trying to do their part" to advance sustainability should be able to robustly prove that that's true or else humbly say that they don't know.

* Note: Photo copyright New York Times 2010.

** I'd just like to say that, as a native New Yorker, I'm not very surprised that Red Hook was causing trouble.

Biosphere Influences on Climate and Respect for Complexity

Photo source

Doing academic research involving climate means that every few times I tell someone what I do I get as a response some question to the effect of "So! What do you think about climate change?" I imagine Sol has similar experiences, and I think that responding to those inquiries in a way that manages to be informative, nontechnical, and contextual to what the person's heard before (even if it's counter to what I'm saying) isn't easy. I have a variety of different responses to this, but one thing I always like to emphasize is how complex the climate system is: over-forcing it the way we are now risks engendering potentially huge and baroque interaction effects that we won't anticipate until they are too late to reverse.

Two recent papers that highlight this issue in an interesting way came out recently in Nature and the Proceedings of the Royal Society B. The first, Smith, Elliot and Lyons' "Methane Emissions from Extinct Megafauna,"details an estimate of the net reduction in methane emissions that followed the (widely hypothesized as human-induced) extinction of large mammals in the Americas around 10,000BCE. They find that a large (they give between 12.5 and 100%) portion of the reduction in methane that we observe around that time period (a short period of global cooling known as the Younger Dryas) could be ascribed to the extinction of megafauna during this time period and the concomitant loss of their digestion-related methane emissions. This is important climatologically because methane is a very potent greenhouse gas, despite its relatively short residency time in the atmosphere, and thus big swings in it can be a major driver of short-term climate change.

The second paper, Boyce and Lee's "An exceptional role for flowering plant physiology in the expansion of tropical rainforests and biodiversity," estimates the effect that angiosperm (i.e., flowering) vegetation has on the climate, specifically on precipitation. Angiosperms have dramatically higher transpiration (evaporative loss through the plant, functionally the same as "plant sweat") rates than non-angiosperm plants and thus can contribute quite a bit to local precipitation, especially when heavily concentrated in areas like the Amazon rain forest. Boyce and Lee find that changing the flowering vegetative biomass in the Amazon from angiosperm to entirely non-angiosperm in a climate model would result in a huge decrease in precipitation, implying that such species are a major driver of the Amazon's extraordinarily high precipitation (which in turn drives a variety of other effects in the climate, as well as affecting rainforest biodiversity).

Now, obviously both of these are new papers and the extent to which the hypotheses they propose will stand up to scrutiny is still unknown. My personal interpretation is that the megafauna methane emissions paper, while intellectually pleasing, probably details a relatively minor part of the climate system while the angiosperm paper is pointing out a very interesting and fundamental part of biosphere-climate interactions. But both papers are nonetheless great examples of how complex the climate system is, and how even now we're still discovering fundamental drivers of climate variability. It's this complexity that should give us pause when we think about our current greenhouse gas emissions: if such a relatively minor (at least climatologically speaking) event as the extinction of some of the larger mammal species could potentially have led to or at least contributed to the Younger Dryas, then forcing the climate in so major a fashion as we currently are should definitely give us pause.

*Note: Image copyrighted L. Cunningham 2006.

Migrating birds on the front page of the NY Times

I'm very impressed and surprised by the coverage. And its a great story about innovations in scientific research. I didn't even realize that when I was a kid watching wildlife videos and learning about the Arctic tern that we couldn't actually observe them migrate. We could only see where they started and ended. But now with smarter tracking technology, we can observe their entire trajectory.

The whole story reminds me of other innovations in observational technology that slingshotted an entire field. For example, the invention of GFP, which can make portions of tissue glow, lead to enormous advances biology and related fields. (Martin Chalfie, one of the inventors who won the Nobel for it, is here at Columbia. I know because I saw him explain the idea to a gymnasium full of kids here with a [humorously] malfunctioning flash-light). I think that a lot of times, when we learn science in [grad]school, there is so much focus on theory, mechanisms and methods that we sometimes forget that the starting point of all science is observation.

PS. If you're like me and did a double take at the article's nonchalant statement about the groundbreaking technology

Geolocators ... just record changing light levels. If scientists can recapture birds carrying geolocators, they can retrieve the data from the devices and use sophisticated computer programs to figure out the location of the birds based on the rising and setting of the sun.

You should check out the website of the geolocator manufacturer Lotek, where they post scientific papers on the method. Here's an abstract from "An advance in geolocation by light" by P. A. Ekstrom (2004):

A new analysis of twilight predicts that for observations made in narrow-band blue light, the shape of the light curve (irradiance vs. sun elevation angle) between +3 and -5.DEG. (87 to 95.DEG. zenith angle) has a particular rigid shape not significantly affected by cloudiness, horizon details, atmospheric refraction or atmospheric dust loading. This shape is distinctive, can be located reliably in measured data, and provides a firm theoretical basis for animal geolocation by template-fitting to irradiance data. The resulting approach matches a theoretical model of the irradiance vs. time-of-day to the relevant portion of a given day's data, adjusting parameters for latitude, longitude, and cloudiness. In favorable cases, there is only one parameter choice that will fit well, and that choice becomes the position estimate. The entire process can proceed automatically in a tag. Theoretical estimates predict good accuracy over most of the year and most of the earth, with difficulties just on the winter side of equinox and near the equator. Polar regions are favorable whenever the sun crosses -5.DEG. to +3.DEG. elevation, and the method can yield useful results whenever the sun makes a significant excursion into that elevation range. Early results based on data taken on land at 48.DEG.N latitude confirm the predictions vs. season, and show promising performance when compared with earlier threshold-based methods.

Sound pollution and sea mammals

This is a really interesting (and easy to read) article in Physics Today (I don't know why it's there) on the impact of sound pollution on sea mammals. It discusses, for example, the correlation of mass beachings and Naval sonar exercises.

Also, one sentence the author tosses out but caught me was:

"Biologists have used estimates of the population size and metabolic rate of sperm whales to calculate that those whales alone probably take about as much biomass out of the ocean as do all human fisheries."