The Marriage between science and values

'Scientific knowledge reveals options. Values determine choices." 

Journalist A. Revkin shares his insights about the roles of science and values when reporting the Pope's recent effort to tackles sustainability during a workshop on "Sustainable humanity, sustainable nature: Our responsibility."

TESSA: An ecosystem services valuation tool for non-expert use at a local level

A UK effort jointly developed by six institutions.  TESSA fits the gap for 'rapid appraisal' of ecosystem services that do not require substantial resources or specialist technical knowledge.  It is designed for local non-specialists. The figure above from this paper shows TESSA's methodological framework. 

Biodiversity target--what to measure?

There has been no global unified system for measuring biodiversity change nor consensus about what to monitor.  To fill this gap, a paper in the recent Science proposed an indicator system called "Essential biodiversity variables."

The impacts of little emperors on Chinese Society

A paper in the recent Science documented the impact of China's One-Child Policy, and they conclude that the policy has produced "less trusting, less trustworthy, more risk-averse, less competitive, more pessimistic, and less conscientious individuals."

The authors conducted standard games from the economics literature, including the Dictator Game to elicit the extent of altruism, the Trust Game for trusting and trust-worthiness, the risk Game for risk attitude, and the Competition Game.  

Guide to citizen science

A UK report reviewed more than 230 citizen science projects and offered advice on how to develop, implement and evaluate them.

Detecting Causality in Complex Ecosystems

A paper in the recent Science developed a method of analyzing time series data that is capable of distinguishing causation from correlation.  The method is based on Granger causality which uses predictability (vs. correlation) to identify causation between time-series variables.

Here are three youtube videos that the authors put together to explain their method.

The art of ecological modeling

A Science article talks about the limitations of ecological models (especially in predicting the dynamics of real ecosystems) and their potentials in operational uses.

"Predicting the dynamics of real ecosystems—or even of components of these ecosystems—will remain beyond the reach of even the best ecosystem models for the foreseeable future (see the figure). However, the emerging body of evidence (3–6), suggests that ecological network models can be used to describe ecosystem characteristics and general behavior, including providing indicators of when ecosystems are being stressed. Successful management of ecological processes will come down to being able to identify and measure the dynamics of influential network components, probably in the form of key species (7)."

Biodiversity loss and its impact on humanity

Another review paper on biodiversity in the latest Nature (to celebrate the coming Rio+20?).  In addition to review two decades of research on BEF, this paper also reviews the impacts of biodiversity loss on ecosystem services.

The paper summarized six consensus statements and four emerging trends on BEF research, all of which are fairly straight forward/established except the last one--"The ecological consequences of biodiversity loss can be predicted from evolutionary history."  For me this is a very strong statement and I wasn't aware of we have learned enough to predict. 


The authors are less confident with the linkage between biodiversity and ecosystem services in making their four statements after reviewing the top 100 papers for each ecosystem services (Table 1).

Statement one

There is now sufficient evidence that biodiversity per se either directly influences (experimental evidence) or is strongly correlated with (observational evidence) certain provisioning and regulating services.

Statement two

For many of the ecosystem services reviewed, the evidence for effects of biodiversity is mixed, and the contribution of biodiversity per se to the service is less well defined.

Statement three

For many services, there are insufficient data to evaluate the relationship between biodiversity and the service.

Statement four

For a small number of ecosystem services, current evidence for the impact of biodiversity runs counter to expectations.

A global synthesis reveals biodiversity loss as a major driver of ecosystem change

A new Nature article used meta-analysis to show the effects of species loss on two ecosystem functions (productivity and decomposition) are of comparable magnitude to the effects of other global environmental changes.  I particularly like the figures the authors put together such as this one:

Another observation is that invasive species stands out as an important drive for both ecosystem functions as well, though that is not the focus of the paper.

How to translate $/household/yr to $/ha/yr when doing spatially explicit benefit transfer?

Somebody asked me the question regarding my 2010 Environmental Management paper.   A great question and here is my answer:

"The key is to find detailed information about the survey design and figure out what is the population surveyed and how large is exactly the area studied.   Then you can calculate the total value by multiplying the per person (or per household) value and the number of people (or household).  The next step is to divide the total value by the size of the study area. 

The steps are easily said than done, of course.  Mostly because valuation studies are not designed for benefit transfer purpose, as a result, one cannot find enough information about survey designs.  This is especially the case for journal articles where authors tend to focus on the innovative side of the research and use very little ink on the survey itself.   Then you can either contact the author or track down other publications that were derived from the same survey.   A project report, for instance, often carries more detailed information about the survey. 

If you still cannot find enough after trying these two approaches, the last resort is to make you own assumptions.   One has to be extremely careful here, because this step might introduce errors.   There are two things you can do to make yourself feel less guilty.  First, to err on the safe side.  It is generally more desirable to come up with a conservative value rather than an outrageously big one.   Second, be transparent by keeping a very good note about what exactly you did."

Special issue: Methodology in mudgment and decision making research

Judgment and decision-making, 6(8), 2011 (open access).

Impact of climate change on the future of biodiversity

A review paper in Ecology Letters and a general conclusion is that "Overall, our review shows that current estimates are very variable, depending on the method, taxonomic group, biodiversity loss metrics, spatial scales and time periods considered. Yet, the majority of models indicate alarming consequences for biodiversity, with the worst-case scenarios leading to extinction rates that would qualify as the sixth mass extinction in the history of the earth."

Figure 4 below demonstrated the points well.





Figure 4.  Projections of loss of biodiversity due to climate change, for different taxonomic, temporal and spatial scales. The width of the box illustrates three levels of generality: global scale and several taxonomic groups (), global scale and only one taxonomic group, continental scale and only one taxonomic group. The box is delimited by the upper and lower boundaries of the intermediate scenario, while maximum and minimum values of the whiskers indicate the highest and lowest biodiversity losses across all projections. This figure illustrates that the different studies (i) generally predict significant biodiversity loss and (ii) use a combination of different biodiversity metrics, taxonomic groups and spatial scale and time horizon, making generalisations difficult. Numbers correspond to references (see Appendix S2 for details and references).