Showing posts with label human impact. Show all posts
Showing posts with label human impact. Show all posts

2.15.2013

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


2.04.2013

Simulations of direct interference in the large-scale water and energy balances of the atmosphere by humans


A recent NCC and a recent GRL article both use simulations to look at how large scale irrigation and energy consumption might alter large scale circulation patterns of the atmosphere.

If I were a grad student with some statistical skills, I would go out into the world and try to detect these effects with data.

Energy consumption and the unexplained winter warming over northern Asia and North America
Guang J. Zhang, Ming Cai & Aixue Hu
Abstract: The worldwide energy consumption in 2006 was close to 498 exajoules. This is equivalent to an energy convergence of 15.8 TW into the populated regions, where energy is consumed and dissipated into the atmosphere as heat. Although energy consumption is sparsely distributed over the vast Earth surface and is only about 0.3% of the total energy transport to the extratropics by atmospheric and oceanic circulations, this anthropogenic heating could disrupt the normal atmospheric circulation pattern and produce a far-reaching effect on surface air temperature. We identify the plausible climate impacts of energy consumption using a global climate model. The results show that the inclusion of energy use at 86 model grid points where it exceeds 0.4 W m−2 can lead to remote surface temperature changes by as much as 1 K in mid- and high latitudes in winter and autumn over North America and Eurasia. These regions correspond well to areas with large differences in surface temperature trends between observations and global warming simulations forced by all natural and anthropogenic forcings1. We conclude that energy consumption is probably a missing forcing for the additional winter warming trends in observations.

Irrigation in California's Central Valley strengthens the southwestern U.S. water cycle
Min-Hui Lo, James S. Famiglietti
Abstract: Characterizing climatological and hydrological responses to agricultural irrigation continues to be an important challenge to understanding the full impact of water management on the Earth's environment and hydrological cycle. In this study, we use a global climate model, combined with realistic estimates of regional agricultural water use, to simulate the local and remote impacts of irrigation in California's Central Valley. We demonstrate a clear mechanism that the resulting increase in evapotranspiration and water vapor export significantly impacts the atmospheric circulation in the southwestern United States, including strengthening the regional hydrological cycle. We also identify that irrigation in the Central Valley initiates a previously unknown, anthropogenic loop in the regional hydrological cycle, in which summer precipitation is increased by 15%, causing a corresponding increase in Colorado River streamflow of ~30%. Ultimately, some of this additional streamflow is returned to California via managed diversions through the Colorado River aqueduct and the All-American Canal.

12.10.2010

Challenges for interdisciplinary journals

The American Meteorological Society has a new (1 yr old) journal Weather Climate and Society that is trying to integrate research across several disciplines. For people like myself, the birth of journals like this is comforting because it suggests there is a growing community of researchers interested in applying hard physical science to address social issues.  This is a good thing.  But like everyone trying to do this, they are running into real challenges.  Here are portions of an editorial that resonated with some of my own experiences.  

Jeffrey K. Lazo
....[A] colleague stopped by to ask my advice on a manuscript concept he was considering submitting to Weather, Climate, and Society. He is an outstanding research meteorologist who has been working with a team on models to improve flood warning systems in developing countries. He was interested in demonstrating the economic benefits of the improved warning system and wanted to apply a cost–loss model. Based on his reading of a number of articles in meteorological journals, the cost–loss model was the method of choice for demonstrating economic value.
My initial reaction was largely visceral, because I have a dislike for the cost–loss model. The cost–loss model has been used extensively in the meteorology literature as “the economic model,” but it does not really show up in the economics literature (I should note that my Ph.D. is in economics and, in six years of graduate school, I never once heard of the cost–loss model). A simple search for “cost–loss model” in AMS publications yields 161 hits. A similar search of the economic literature yielded none....
My concern is that the cost–loss model as used in most articles in the meteorology literature does not even begin to capture the full value of economics and build upon the extensive literature in economics on the value of information and decision making under uncertainty. It is simply too simple....
That said, the first issue of Weather, Climate, and Society contained an article based on a theoretical extension of the cost–loss model (Millner 2009; in fact, I recommend reading Millner for an explanation of the cost–loss model). In that article, Millner showed that incorporating a specific behavioral feature in the cost–loss model resulted in net benefit estimates potentially significantly lower than those derived from the basic model. His article demonstrated that behavioral aspects limit the effectiveness of the cost–loss model. I feel this should be read as a demonstration that the meteorological community needs to move beyond the cost–loss model. Building in part on the limitations of the cost–loss model that Millner’s work suggests, I encourage the meteorological community to move beyond the use of that model as the basis for defining economic value....
Weather, Climate, and Society aims to publish “scientific research and analysis on the interactions of weather and climate with society.” This editor’s opinion is that this will largely involve the integration of the social sciences applied to topics of hydrometeorological concern (including weather, water, and climate broadly defined). In light of the prior discussion on cost–loss models, this means we need to better integrate valid economics as economic theory, methods, and practice frame economics with analysis of hydrometeorological issues. More broadly, we need to use appropriate theories and methods from all of the social sciences and not necessarily “accepted” versions of social sciences from the physical sciences perspective.
All of the social sciences have extensive bodies of knowledge they can bring to the study of hydrometeorological issues. Some have a longer history of examining issues related to weather, water, and climate; for instance, sociologists have long studied evacuation decision making during hurricanes. However, for the most part the research and literature is rather thin at the intersection of social and physical sciences relevant to audiences of Weather, Climate, and Society.
Given this landscape, there are definite challenges for the authors, reviewers, and editors for this journal. First, is that most of us (authors, reviewers, and editors) are fairly new to this effort at developing a highly disciplinary but very broadly focused journal combining atmospheric and social sciences. There is a learning curve at this early stage of the journal, because we are all developing and setting standards and expectations. There have been and will continue to be some frustrations as these are clarified. However, as these are clarified and we move forward,Weather, Climate, and Society will be the premier journal for interdisciplinary work “at the interface of weather and/or climate and society.”
There are also difficulties in writing, reviewing, and editing manuscripts for such a highly interdisciplinary journal. For instance, authors, reviewers, and editors for economics journals are almost always economists. I suspect authors, reviewers, and editors for meteorology journals are almost always meteorologists, or at least in general from the “hard” sciences. In addition to meteorologists, authors, reviewers, and editors for Weather, Climate, and Society are from the “harder sciences” such as economists, sociologists, geographers, anthropologists, etc. One challenge for authors will be to maintain high standards for their research while also being able to respond to very diverse (and sometimes divergent) critiques from reviewers with expertise from different disciplines.
For the time being at least, this may make Weather, Climate, and Society the most difficult journal across all American Meteorological Society (AMS) publications to publish in and to be an editor for. However, it may well also make Weather, Climate, and Society the most valuable and dynamic journal in terms of moving the various disciplines forward in new, challenging, and interesting areas of societally relevant research, methods, and applications.
(I hope I cut out enough of it that I'm not infringing on copyrights). 

12.01.2009

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."