12.27.2011

Not just us humans

I saw this BBC video from Planet Earth on a flight to Asia. Very startling.



12.26.2011

Geoengineering research goes mainstream

The results of this paper are not very surprising, but what is surprising is that it was published in Nature Climate Change.  This is not because the article is bad, but because the politics of publishing research on geoengineering has been remarkably hostile.

In 2007, colleagues and I (lead by Andy Lacis) wrote this paper which was well-executed and extremely interesting, but nobody would touch it.

Despite years of speculation and vague talk, peer-reviewed research on geoengineering is remarkably scarce. Nearly the entire community of geoengineering scientists could fit comfortably in a single university seminar room, and the entire scientific literature on the subject could be read during the course of a transatlantic flight. Geoengineering continues to be considered a fringe topic.  
Many scientists have been reluctant to raise the issue for fear that it might create a moral hazard: encouraging governments to deploy geoengineering rather than invest in cutting emissions. Indeed, geoengineering ventures will be viewed with particular suspicion if the nations funding geoengineering research are not also investing in dramatically reducing their emissions of carbon dioxide and other greenhouse gases. Many scientists also rightly fear that grants for geoengineering research would be subtracted from the existing funds for urgently needed climate-science research and carbon-abatement technologies. But there is a pressing need for a better understanding of geoengineering, rooted in theoretical studies and empirical field measurements. The subject also requires the talents of engineers, few of whom have joined the small group of scientists studying these techniques.
And last year (2010) I wrote a fellowship grant to look at geoengineering impacts and, perhaps not surprisingly, it did not get funded (of course, I'd like to blame that on the politics and not my lousy writing...).

Anyway, enough prologue. Here's the actual article that came out.  No real surprises, but still worthy of note for the reasons above.
Effectiveness of stratospheric solar-radiation management as a function of climate sensitivityKatharine L. Ricke, Daniel J. Rowlands, William J. Ingram, David W. Keith & M. Granger Morgan
Abstract: If implementation of proposals to engineer the climate through solar-radiation management (SRM) ever occurs, it is likely to be contingent on climate sensitivity. However, modelling studies examining the effectiveness of SRM as a strategy to offset anthropogenic climate change have used only the standard parameterizations of atmosphere–ocean general circulation models that yield climate sensitivities close to the Coupled Model Intercomparison Project mean. Here, we use a perturbed-physics ensemble modelling experiment to examine how the response of the climate to SRM implemented in the stratosphere (SRM-S) varies under different greenhouse-gas climate sensitivities. When SRM-S is used to compensate for rising atmospheric concentrations of greenhouse gases, its effectiveness in stabilizing regional climates diminishes with increasing climate sensitivity. However, the potential of SRM-S to slow down unmitigated climate change, even regionally, increases with climate sensitivity. On average, in variants of the model with higher sensitivity, SRM-S reduces regional rates of temperature change by more than 90% and rates of precipitation change by more than 50%.

a,b, Five-year running-mean global mean near-surface (1.5 m) air temperature (a) and five-year running-mean global mean precipitation rate (b), all shown over the length of the 80 model-year simulations. Copyright: Nature Climate Change.

12.23.2011

New tool for interfering with malaria transmission

Geoff Johnston, a doctoral candidate at Columbia's PhD in Sustainable Development, is on the team behind this recent study in PNAS.  He's promised us a non-technical summary soon.


Sophie H. Adjalleya, Geoffrey L. Johnston, Tao Li, Richard T. Eastman, Eric H. Ekland, Abraham G. Eappen, Adam Richman, B. Kim Lee Sim, Marcus C. S. Lee, Stephen L. Hoffman, and David A. Fidock

Abstract: Clinical studies and mathematical models predict that, to achieve malaria elimination, combination therapies will need to incorporate drugs that block the transmission of Plasmodium falciparum sexual stage parasites to mosquito vectors. Efforts to measure the activity of existing antimalarials on intraerythrocytic sexual stage gametocytes and identify transmission-blocking agents have, until now, been hindered by a lack of quantitative assays. Here, we report an experimental system using P. falciparum lines that stably express gametocyte-specific GFP-luciferase reporters, which enable the assessment of dose- and time-dependent drug action on gametocyte maturation and transmission. These studies reveal activity of the first-line antimalarial dihydroartemisinin and the partner drugs lumefantrine and pyronaridine against early gametocyte stages, along with moderate inhibition of mature gametocyte transmission to Anopheles mosquitoes. The other partner agents monodesethyl-amodiaquine and piperaquine showed activity only against immature gametocytes. Our data also identify methylene blue as a potent inhibitor of gametocyte development across all stages. This thiazine dye almost fully abolishes P. falciparum transmission to mosquitoes at concentrations readily achievable in humans, highlighting the potential of this chemical class to reduce the spread of malaria.

From the author summary:
The scale of the malaria epidemic remains vast, causing up to 225 million symptomatic infections and ∼780,000 deaths each year, primarily in sub-Saharan Africa. Despite this sobering backdrop, there are encouraging signs that treating infected individuals with antimalarial therapies and combating the Anopheles mosquito vector with insecticides can substantially reduce the burden of disease. First-line therapies rely on pairing potent derivatives of the Chinese plant extract artemisinin with longer-lasting partner drugs in regimens referred to as artemisinin-based combination therapies. Clinical reports and mathematical models indicate that additional reductions in disease incidence will require treatments that not only cure patients but also decrease the transmission of malarial parasites to Anopheles mosquitoes (1). Here, we have investigated the ability of various antimalarial agents to inhibit transmission. This work reveals that methylene blue (MB), the first synthetic compound ever used in clinical therapy (2), has potent transmission-blocking activity superior to current first-line therapies. 
Interruption of transmission can be achieved with drugs that inhibit the development of parasite sexual forms, termed gametocytes, within red blood cells. In the case of the most lethal human malaria pathogen, Plasmodium falciparum, these gametocytes progress through five developmental stages over 10–12 d before becoming infectious to mosquitoes (Fig. P1A). Prior studies have found that some drugs that target the disease-causing asexual blood stages also inhibit early stage gametocytes (3). However, identifying compounds that inhibit the metabolically less active mature stages has proven considerably more difficult, in part because of a lack of robust experimental tools. To address this concern, we have developed recombinant parasite lines and analytical methods that enable precise measurements of drug action against gametocytes as they mature and attain infectivity. 
To investigate the abilities of known antimalarials to affect gametocyte viability at different stages, we genetically modified P. falciparum parasite lines to express GFP-luciferase reporters from gene promoters known to be active in early, mid, or late stage gametocytes. The production of gametocytes was triggered by starvation-induced stress, and their subsequent development and gametocyte maturation were monitored by quantifying luciferase activity. Measurements of the rate of action of antimalarial compounds, tested at different doses in vitro, revealed the remarkable potency of the thiazine dye MB against all developmental stages (Fig. P1A). Subsequent experiments revealed that MB almost fully blocked transmission of P. falciparum gametocytes to Anopheles mosquitoes (Fig. P1B), reducing parasite infectivity by 78–100%. The small proportion of mosquitoes that were infected had a >98% reduction in the numbers of parasites developing in the midgut. Most of the effect of MB on parasite transmission can be attributed to its potent activity against mature stage V gametocytes. Parallel studies also observed a potent effect with dihydroartemisinin, the active metabolite of artemisinin compounds, with inhibition occurring primarily against early stage gametocytes. Comparable activity against early stages was observed with key partner drugs, including amodiaquine and lumefantrine (4). 
The experimental system that we developed for these studies will enable high-throughput screening to identify additional transmission-blocking compounds. Our study also provides experimental tools to further probe gametocyte biology, including studies on the cellular processes and molecular components that dictate the formation of gametocytes and promote transmission (5). A renewed emphasis on this phase of the malarial parasite life cycle, using reporter systems such as the one described here, promises to further aid expanding efforts to roll back malaria.

12.22.2011

Annual Review of Resource Economics


The Annual Reviews have come out with a new journal (a few issues old) that will be extremely useful resource for many FE readers: Annual Review of Resource Economics.
ABOUT THIS JOURNAL: The Annual Review of Resource Economics, provides authoritative critical reviews evaluating the most significant research developments in resource economics, focusing on agricultural economics, environmental economics, renewable resources, and exhaustible resources.
To get a sense of the journal, I just cut and pasted the most recent table of contents below (authors aren't listed, but many of them are quite distinguished).
Plowing Through the Data
Methods for Performance Evaluations and Impact Measurement
Green National Income and Green National Product
Behavior, Robustness, and Sufficient Statistics in Welfare Measurement
The Challenges of Improving the Economic Analysis of Pending Regulations: The Experience of OMB Circular
Commodity Booms and Busts
Food Quality: The Design of Incentive Contracts
Nutritional Labeling and Consumer Choices
Efficiency Advantages of Grandfathering in Rights-Based Fisheries Management
Game Theory and Fisheries
Natural Resource Management: Challenges and Policy Options
The New Economics of Evaluating Water Projects
Management of Hazardous Waste and Contaminated Land
The Economics of Infection Control
The Economics of Natural Disasters
Valuing Mortality Risk Reductions: Progress and Challenges
Pricing Nature
The Economics of Non-Point-Source Pollution
Microeconometric Strategies for Dealing with Unobservables and Endogenous Variables in Recreation Demand Models
The Environment and Trade
The Social Cost of Carbon
Corporate Average Fuel Economy Standards and the Market for New Vehicles 

12.20.2011

Where do I get a forecast of ENSO?

My colleagues and I have been pushing the idea that ENSO forecasts should be broadly integrated into economic, security and social policies in the tropics and subtropics.  In a talk to policy folks yesterday, I tried to point them towards an excellent resource provided by the International Research Institute for Climate and Society (at Columbia) that aggregates ENSO forecasts across many modeling groups (here).  Their current forecast for 2012 (Sep-Nov) is a 27% chance of El Nino, a 52% chance of neutral conditions and a 21% chance of La Nina.

More resources here.

Historical projections from many different models (both physics-based dynamical models and statistical models) with actual observations overlaid in black:


Forecasts from various models going out until October of next year:


For a reference on our ability to forecast ENSO, see Chen et al. They reconstruct forecasts using the LDEO model going back more than a century:

Time series of SST anomalies averaged in the NINO3.4 region (5° S–5° N, 120–170° W). The red curve is monthly analysis of [reconstructed observations] and the blue curve is the LDEO5 prediction at 6-month lead. Source: Nature.

and show, somewhat incredibly, that strong El Nino events can be reasonably forecast (corr ~ 0.75) up to twenty months in advance:


These are shown as a function of start month and lead. The straight green lines denote the verification month of May. The left panel is based on all monthly anomalies, while the right panel is for anomalies with amplitudes greater than 0.7 °C. The colour bar shows the range of correlation coefficients. Source: Nature.

12.19.2011

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]

12.14.2011

12.12.2011

Fukushima's long-term implications

Two articles came out in PNAS Environmental Sciences this week estimating the fallout from the Fukushima nuclear disaster (Yasunari et al. and Kinoshita et al.). Of particular concern is the following from Yasunari et al.:
As a general characteristic, most of the eastern parts of Japan were effected by a total 137 Cs deposition of more than 1,000 MBq km−2 . Our estimates show that the area around NPP in Fukushima, secondarily effected areas (Miyagi and Ibaraki prefectures), and other effected areas (Iwate, Yamagata, Tochigi, and Chiba prefectures) had 137 Cs depositions of more than 100,000, 25,000, and 10,000 MBq km−2 , respectively. Airborne and ground-based survey measurements jointly carried out by MEXT and the US Department of Energy (DOE) (21) show high 137 Cs deposition amounts were observed northwestward and up to a distance of 80 km from Fukushima NPP. It was estimated from the first measurement that by April 29, more than 600,000 MBq km−2 had been deposited in the area, which is greater than our estimate of less than 500,000 MBq km−2 (Fig. 2A), yet well within the range of uncertainty of our method (Fig. S4).
1,000 MBq (megabecquerels) per square kilometer is 1 kilobecquerel per square meter, so the three broad exposure estimates correspond to 100, 25, and 10 kBq m-2, with maximum treatments around 500-600 kBq m-2. To answer how worried we should be about this, we turn to Almond, Edlund, and Palme, 2009:
We use prenatal exposure to Chernobyl fallout in Sweden as a natural experiment inducing variation in cognitive ability. Students born in regions of Sweden with higher fallout performed worse in secondary school, in mathematics in particular. Damage is accentuated within families (i.e., siblings comparison) and among children born to parents with low education. In contrast, we detect no corresponding damage to health outcomes. To the extent that parents responded to the cognitive endowment, we infer that parental investments reinforced the initial Chernobyl damage. From a public health perspective, our findings suggest that cognitive ability is compromised at radiation doses currently considered harmless.
The heaviest fallout in Sweden (also due to Cesium 137 contamination) was around 65 kBq m-2 (see figure 2 of the paper). Moreover Japan's population density is roughly an order of magnitude larger than Sweden's. Given this, it looks like the long term human costs of this disaster may be absolutely staggering.

12.09.2011

Who self-identifies as a sustainability scientist?


The footprint of sustainability science in terms of traditional scientific disciplines. (A) The percent distribution in terms of ISI disciplines determined based on the classification of journals where publications appeared. The field receives its largest contribution (about 34%) from the social sciences, and other large contributions from biology and chemical, mechanical and civil engineering. Other important contributors are from medicine, Earth sciences, and infectious diseases. A similar analysis for sustainable development shows the same patterns with only a small 5% increase in the relative contribution of the social sciences vs. biology. Copyright PNAS.
Geographic distribution of sustainability science publications. (A) National counts of number of publications. (B) National counts for number of citations received. Fig. S4 shows the analogous map for number of citations per paper. The maps show the wide geographic distribution of the field of sustainability science. This is unusual as compared to typical specialized fields in the natural sciences, for example, and notably demonstrates the quality and quantity of contributions from many developing nations. Note the strength of smaller nations such as Australia, the United Kingdom, the Netherlands, Sweden, South Africa, Kenya, and of Brazil and China. Copyright PNAS.



Cool google earth visualization here. Related post here.  The paper (open access):
Evolution and structure of sustainability science 
Luís M. A. Bettencourta and Jasleen Kaur
Abstract: The concepts of sustainable development have experienced extraordinary success since their advent in the 1980s. They are now an integral part of the agenda of governments and corporations, and their goals have become central to the mission of research laboratories and universities worldwide. However, it remains unclear how far the field has progressed as a scientific discipline, especially given its ambitious agenda of integrating theory, applied science, and policy, making it relevant for development globally and generating a new interdisciplinary synthesis across fields. To address these questions, we assembled a corpus of scholarly publications in the field and analyzed its temporal evolution, geographic distribution, disciplinary composition, and collaboration structure. We show that sustainability science has been growing explosively since the late 1980s when foundational publications in the field increased its pull on new authors and intensified their interactions. The field has an unusual geographic footprint combining contributions and connecting through collaboration cities and nations at very different levels of development. Its decomposition into traditional disciplines reveals its emphasis on the management of human, social, and ecological systems seen primarily from an engineering and policy perspective. Finally, we show that the integration of these perspectives has created a new field only in recent years as judged by the emergence of a giant component of scientific collaboration. These developments demonstrate the existence of a growing scientific field of sustainability science as an unusual, inclusive and ubiquitous scientific practice and bode well for its continued impact and longevity. 

12.08.2011

Political implications of perceived agreement on climate change

Support for climate policy and societal action are linked to perceptions about scientific agreement
Ding Ding, Edward W. Maibach, Xiaoquan Zhao, Connie Roser-Renouf & Anthony Leiserowitz
Abstract: Although a majority of US citizens think that the president and Congress should address global warming, only a minority think it should be a high priority. Previous research has shown that four key beliefs about climate change—that it is real, human caused, serious and solvable—are important predictors of support for climate policies. Other research has shown that organized opponents of climate legislation have sought to undermine public support by instilling the belief that there is widespread disagreement among climate scientists about these points—a view shown to be widely held by the public. Here we examine if this misperception is consequential. We show that the misperception is strongly associated with reduced levels of policy support and injunctive beliefs (that is, beliefs that action should be taken to mitigate global warming). The relationship is mediated by the four previously identified key beliefs about climate change, especially people’s certainty that global warming is occurring. In short, people who believe that scientists disagree on global warming tend to feel less certain that global warming is occurring, and show less support for climate policy. This suggests the potential importance of correcting the widely held public misperception about lack of scientific agreement on global warming.
I suppose this is more rational than this, but that's not saying much...

12.02.2011

Conflict News

A new paper finds evidence to support the "rapacity" or "prize" mechanism as an important factor driving civil conflict.

The Peace Research Institute of Oslo has released a gridded version of it's conflict dataset PRIO-GRID 1.0 (h/t Kyle)

The Office of the Under Secretary of Defense released a report on Trends and Implications of Climate Change for National and International Security, including recommendations for next steps.

12.01.2011

Sprawl

Here's a fun 2006 QJE paper that recently ran into. I especially like that they authors made a free down-loadable poster to go along with the paper!

CAUSES OF SPRAWL: A PORTRAIT FROM SPACE
MARCY BURCHFIELD, HENRY G. OVERMAN, DIEGO PUGA, MATTHEW A. TURNER

Abstract: We study the extent to which U. S. urban development is sprawling and what determines differences in sprawl across space. Using remote-sensing data to track the evolution of land use on a grid of 8.7 billion 30 30 meter cells, we measure sprawl as the amount of undeveloped land surrounding an average urban dwelling. The extent of sprawl remained roughly unchanged between 1976 and 1992, although it varied dramatically across metropolitan areas. Ground water availability, temperate climate, rugged terrain, decentralized employment, early public transport infrastructure, uncertainty about metropolitan growth, and unincorporated land in the urban fringe all increase sprawl.