International Institute for Applied Systems Analysis

About: International Institute for Applied Systems Analysis is a nonprofit organization based out in Laxenburg, Austria. It is known for research contribution in the topics: Population & Greenhouse gas. The organization has 1369 authors who have published 5075 publications receiving 280467 citations. The organization is also known as: IIASA.

A global and spatially explicit assessment of climate change impacts on crop production and consumptive water use.

Abstract: Food security and water scarcity have become two major concerns for future human's sustainable development, particularly in the context of climate change. Here we present a comprehensive assessment of climate change impacts on the production and water use of major cereal crops on a global scale with a spatial resolution of 30 arc-minutes for the 2030s (short term) and the 2090s (long term), respectively. Our findings show that impact uncertainties are higher on larger spatial scales (e.g., global and continental) but lower on smaller spatial scales (e.g., national and grid cell). Such patterns allow decision makers and investors to take adaptive measures without being puzzled by a highly uncertain future at the global level. Short-term gains in crop production from climate change are projected for many regions, particularly in African countries, but the gains will mostly vanish and turn to losses in the long run. Irrigation dependence in crop production is projected to increase in general. However, several water poor regions will rely less heavily on irrigation, conducive to alleviating regional water scarcity. The heterogeneity of spatial patterns and the non-linearity of temporal changes of the impacts call for site-specific adaptive measures with perspectives of reducing short- and long-term risks of future food and water security.

Understanding mutualism when there is adaptation to the partner

Abstract: Summary 1 A mutualism is a mutually beneficial interaction between individuals of two species. Here we show that the degree of benefit resulting from an interaction depends on whether adaptation within the mutualism is considered. 2 A species’ proximate response measures the short-term effect of addition or removal of the partner species, without allowing for any adaptation. We define a proximate mutualism as an interaction in which removal of each partner results in a decreased performance of the other, i.e. both species show a positive proximate response to the presence of the partner. 3 A proximate mutualism might, however, only reflect evolved dependence (i.e. the species has lost its ability to perform well without the partner). Some authors therefore insist on an ultimate criterion, regardless of the use of proximate responses in almost all empirical studies. 4 A species’ ultimate response measures the long-term effect of adding or removing the partner species, thus allowing the focal species to adapt. In an ultimate mutualism neither partner could ever have performed as well without the other. In other words, a mutualism is called ultimate if both species show a positive ultimate response to the presence of the partner. Despite the conceptual attractiveness of this definition, ultimate responses are difficult to measure, rendering its use operationally problematic. 5 Mutualistic evolution , the evolution of a trait that is costly to the bearer but beneficial to its partner, is not, paradoxically, a necessary consequence of either proximate or ultimate mutualism. Another counterintuitive result is that even obligate mutualisms are not necessarily ultimate interactions. 6 We conclude that the proximate response is the only workable criterion for mutualism. Our understanding of mutualism, however, requires further evaluation of how evolved dependence may be responsible for such responses. 7 These concepts clarify the ongoing debate about whether plant‐herbivore interactions can be considered as mutualistic. 8 This is not a semantic case of hair splitting: naive aspects in current views of mutualism need revision. In most, if not all, interactions now considered as mutualisms, some of the measured benefits are likely to result from evolved dependence, rather than what we would like to consider as ultimate benefits.

Breaking the Waves? Does Education Mediate the Relationship Between Youth Bulges and Political Violence?

Abstract: Much of the developing world has experienced a decline in mortality, while fertility often has remained high. This has produced youthful populations in many countries, generally referred to as"youth bulges."Recent empirical research suggests that youth bulges may be associated with increased risks of political violence and conflict. This paper addresses ways that education may serve as a strategy to reduce the risk of political violence, particularly in the context of large cohorts of young males. The authors use a new education dataset measuring educational attainment. The dataset is constructed using demographic back-projection techniques, and offers uninterrupted time-series data for 120 countries. The empirical analysis finds evidence that large, young male population bulges are more likely to increase the risk of conflict in societies where male secondary education is low. The effect on conflict risk by low education and large youth populations is particularly strong in low and middle-income countries. This is especially challenging for Sub-Saharan Africa, the region facing the youngest age structure and the lowest educational attainment levels. Although quantitative studies generally find a strong relationship between indicators of development and conflict risk, the results suggest that poor countries do have some leverage over reducing conflict potential through increased educational opportunities for young people. There is further evidence that the interaction of large youth cohorts and low education levels may be mediated by structural economic factors. The study supports broad policy interventions in education by relaxing concerns about the consequences of rapid educational expansion.