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.

Accounting for the climate–carbon feedback in emission metrics

Abstract: . Most emission metrics have previously been inconsistently estimated by including the climate–carbon feedback for the reference gas (i.e. CO2) but not the other species (e.g. CH4). In the fifth assessment report of the IPCC, a first attempt was made to consistently account for the climate–carbon feedback in emission metrics. This attempt was based on only one study, and therefore the IPCC concluded that more research was needed. Here, we carry out this research. First, using the simple Earth system model OSCAR v2.2, we establish a new impulse response function for the climate–carbon feedback. Second, we use this impulse response function to provide new estimates for the two most common metrics: global warming potential (GWP) and global temperature-change potential (GTP). We find that, when the climate–carbon feedback is correctly accounted for, the emission metrics of non-CO2 species increase, but in most cases not as much as initially indicated by IPCC. We also find that, when the feedback is removed for both the reference and studied species, these relative metric values only have modest changes compared to when the feedback is included (absolute metrics change more markedly). Including or excluding the climate–carbon feedback ultimately depends on the user's goal, but consistency should be ensured in either case.

Forest fine‐root production and nitrogen use under elevated CO2: contrasting responses in evergreen and deciduous trees explained by a common principle

Abstract: Despite the importance of nitrogen (N) limitation of forest carbon (C) sequestration at rising atmospheric CO2 concentration, the mechanisms responsible are not well understood. To elucidate the interactive effects of elevated CO2 (eCO2) and soil N availability on forest productivity and C allocation, we hypothesized that (1) trees maximize fitness by allocating N and C to maximize their net growth and (2) that N uptake is controlled by soil N availability and root exploration for soil N. We tested this model using data collected in Free-Air CO2 Enrichment sites dominated by evergreen (Pinus taeda; Duke Forest) and deciduous [Liquidambar styraciflua; Oak Ridge National Laboratory (ORNL)] trees. The model explained 80–95% of variation in productivity and N-uptake data among eCO2, N fertilization and control treatments over 6 years. The model explains why fine-root production increased, and why N uptake increased despite reduced soil N availability under eCO2 at ORNL and Duke. In agreement with observations at other sites, the model predicts that soil N availability reduced below a critical level diminishes all eCO2 responses. At Duke, a negative feedback between reduced soil N availability and N uptake prevented progressive reduction in soil N availability at eCO2. At ORNL, soil N availability progressively decreased because it did not trigger reductions in N uptake; N uptake was maintained at ORNL through a large increase in the production of fast turnover fine roots. This implies that species with fast root turnover could be more prone to progressive N limitation of carbon sequestration in woody biomass than species with slow root turnover, such as evergreens. However, longer term data are necessary for a thorough evaluation of this hypothesis. The success of the model suggests that the principle of maximization of net growth to control growth and allocation could serve as a basis for simplification and generalization of larger scale forest and ecosystem models, for example by removing the need to specify parameters for relative foliage/stem/root allocation.

Abuse against elderly in India--the role of education.

Abstract: Abuse against the elderly is recognized as an important challenge to elderly health, but its determinants are not yet well understood. We present findings from a new dataset which covers a representative sample of the population aged 60 years and above from seven Indian states across India – all of which have a higher proportion aged 60 plus compared to the national average. Earlier studies suggest that schooling levels can be relevant in determining the level of abuse against seniors. This study focuses on the role of education on the prevalence of elderly abuse in India. We conduct an analysis of cross sectional primary data that contains information on elderly abuse. The households in the sample were randomly selected from the seven demographically oldest states in India. These states are Himachal Pradesh, Kerala, Maharashtra, Odisha, Punjab, Tamil Nadu and West Bengal. A total of 9852 elderly from 8329 households were interviewed. The statistical analysis is based on logistic regression to understand the independent relation of education with abuse against the elderly. Our findings reveal that 11% of 60+ year olds have experienced at least one type of elderly abuse (Physical 5.3%, Verbal 10.2%, Economic 5.4%, Disrespect 6%, Neglect 5.2%). The most common perpetrator is the son, who is reported to be responsible for the abuse among 41% of male victims and 43% of female victims. Formal education among elderly beyond a certain level (8 years) has a strong relation with reduced violence against elderly. Our findings suggest that level of schooling among elderly is strongly negatively related to abuse against them. More members in the household reduces the chance of abuse while having a greater number of children increases the chance of abuse (neglect and verbal abuse). We find that education even after controlling for wealth and other relevant variables is the factor that most consistently lowers elderly abuse. However, the relation of education to abuse is limited to those with more than 8 years of schooling. This suggests that the ongoing educational expansion beyond the basic schooling years in India may lead to a decline in the incidence of elderly abuse.