Environmental and Political Factors Combine to Exacerbate Syrian Drought that Underpins Unrest

by Caroline Hays

Major climate events have social and political ramifications beyond their environmental impacts. In a recent study, Kelley et al. (2015) examine the extent of the drought in Syria that began in the winter of 2006/2007 and consider how it impacted the country socially and politically. The authors find that, although Syria has experienced several multiyear (three or more) droughts in the last 80 years, the most recent drought is the most extreme on record. Additionally, the authors note that three of the four most severe droughts recorded in Syria have taken place in the last 25 years. They connect the dots between anthropogenic climate effects, drought, agricultural collapse, and mass human migration, presenting a more comprehensive picture of a major climate event than is often shown. Continue reading

How Viable are Green Clubs?

by Caitlin Suh

Matthew Potoski (2015) analyzes a different method of dealing with climate change than with government policies and action that he calls “Green clubs.” Green clubs are the author’s nickname for voluntary environmental programs that target corporations as the subject of climate change adaption.

Green clubs are analogous with country clubs. Just as country clubs give their patrons exclusive bragging rights and use of their facilities in exchange for monthly or yearly dues, these green clubs offer a club good such as environmental technology or certifications of environmentally conscious business practices in exchange for their efforts to reduce the detrimental effects of climate change. Continue reading

High and Distinct Range-Edge Genetic Diversity despite local Bottlenecks

 

by Cameron Lukos

The genetic consequences of being at the edge of species ranges has been the subject of much debate. Populations that occur at low latitude ranges are expected to retain high unique genetic diversity. Less favorable environments that limit population size at the range edges may have caused genetic erosion that has a stronger effect than past events. This study by Assis et al. (2013) provided a test of whether the population declines at the peripheral range might be shown in decreasing diversity and increasing population isolation and differentiation. The authors compared population genetic differentiation and diversity with trends in abundance along a latitudinal gradient to the furthest extents of the range of a sea kelp, Saccorhiza polyschides. Assis et al. also looked at recent bottleneck events to determine whether the recent recoded distributional shifts had a negative impact on the population size. They found that there was decreasing population density and increasing spatial fragmentation and local extinction at the southern edge. The genetic data revealed two distinct groups and a central mixed group. As the authors had predicted there was higher differentiation and evidence of bottleneck at the southern edge but instead of a decrease there was an increase in genetic diversity suggesting that extinction and recolonization had not reduced diversity and that this may be evidence of a process of shifting genetic baselines. Continue reading