This paper analyses the vulnerability of South African agriculture to climate change and variability by developing a vulnerability index and comparing vulnerability indicators across the nine provinces of the country. Nineteen environmental and socio-economic indicators are identified to reflect the three components of vulnerability: exposure, sensitivity, and adaptive capacity. The results of the study show that the regions most exposed to climate change and variability do not always overlap with those experiencing high sensitivity or low adaptive capacity. Furthermore, vulnerability to climate change and variability is intrinsically linked with social and economic development. The Western Cape and Gauteng provinces, which have high levels of infrastructure development, high literacy rates, and low shares of agriculture in total GDP, are relatively low on the vulnerability index. In contrast, the highly vulnerable regions of Limpopo, Kwazulu-Natal and the Eastern Cape are characterised by densely populated rural areas, large numbers of small-scale farmers, high dependency on rain-fed agriculture and high land degradation. These large differences in the extent of vulnerability among provinces suggest that policymakers should develop region-specific policies and address climate change at the local level.

Armed conflict within nations has had disastrous humanitarian consequences throughout much of the world. Here we undertake the first comprehensive examination of whether global climate change will exacerbate armed conflict in sub-Saharan Africa. We find strong historical linkages between civil war and temperature on the continent, with warmer years leading to significant increases in the likelihood of war. When combined with climate model projections of future temperature trends, this historical response to temperature suggests a roughly 60% increase in armed conflict incidence by 2030, or an additional 390,000 battle deaths if future wars are as deadly as recent wars.  Our results suggest an urgent need to reform African governments' and foreign aid donors' policies to deal with rising temperatures.

Recent work has shown that current bio-energy policy directives may have harmful, indirect consequences, affecting both food security and the global climate system. An additional unintended but direct effect of large-scale biofuel production is the impact on local and regional climate resulting from changes in the energy and moisture balance of the surface upon conversion to biofuel crops. Using the latest version of the WRF modeling system we conducted twenty-four, midsummer, continental-wide, sensitivity experiments by imposing realistic biophysical parameter limits appropriate for bio-energy crops in the Corn Belt of the United States. In the absence of strain/crop-specific parameterizations, a primary goal of this work was to isolate the maximum regional climate impact, for a trio of individual July months, due to land-use change resulting from bio-energy crops and to identify relative importance of each biophysical parameter in terms of its individual effect. Maximum, local changes in 2 m temperature of the order of 1C occur for the full breadth of albedo (ALB), minimum canopy resistance (RC_MIN) and rooting depth (ROOT) specifications, while the regionally (105W-75W and 35N-50N) and monthly averaged response of 2 m temperature was most pronounced for the ALB and RC_MIN experiments, exceeding 0.2C. The full range of the albedo variability associated with biofuel crops may be sufficient to drive regional changes in summertime rainfall. Individual parameter effects on 2 m temperature are additive, highlight the cooling contribution of higher leaf area index (LAI) and ROOT for perennial grasses (e.g., Miscanthus) versus annual crops (e.g., maize), and underscore the necessity of improving location- and vegetation-specific representation of RC_MIN and ALB.