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 new scenario logic for the Paris Agreement long-term temperature goal

Abstract: To understand how global warming can be kept well below 2 degrees Celsius and even 1.5 degrees Celsius, climate policy uses scenarios that describe how society could reduce its greenhouse gas emissions. However, current scenarios have a key weakness: they typically focus on reaching specific climate goals in 2100. This choice may encourage risky pathways that delay action, reach higher-than-acceptable mid-century warming, and rely on net removal of carbon dioxide thereafter to undo their initial shortfall in reductions of emissions. Here we draw on insights from physical science to propose a scenario framework that focuses on capping global warming at a specific maximum level with either temperature stabilization or reversal thereafter. The ambition of climate action until carbon neutrality determines peak warming, and can be followed by a variety of long-term states with different sustainability implications. The approach proposed here closely mirrors the intentions of the United Nations Paris Agreement, and makes questions of intergenerational equity into explicit design choices. Fundamental value judgments about acceptable maximum levels of climate change and future reliance on controversial technologies can be made explicitly in climate scenarios, thereby addressing the intergenerational bias present in the scenario literature.

Probabilistic maturation reaction norms: their history, strengths, and limitations

Abstract: Probabilistic maturation reaction norms (PMRNs) are emerging as a flexible and general tool for characterizing phenotypic plasticity in maturation schedules. Describing an organism's probability of maturing as a function of its age and size, PMRNs offer several beneficial features: (1) PMRNs overcome systematic biases that previously marred the estimation of deterministic matu- ration reaction norms for populations with probabilistic growth and maturation; (2) PMRNs remove the effects of varying mortality rates and average juvenile somatic growth rates from descriptions of maturation schedules; (3) PMRNs are defined at the level of individuals and can thus be treated as phenotypes when applying methods of quantitative genetics; (4) PMRNs serve as indispensable ingredients in process-based dynamical models of a population's age and size structure; and (5) PMRNs are readily extended to include effects on maturation of individual or environmental factors other than age and size. Owing to this combination of features, PMRNs allow many effects of phenotypic plasticity to be stripped away from the description of maturation schedules, so that residual trends are suggestive of genetic adaptation in maturation schedules. Here we review the historical developments that led to the introduction of PMRNs and address frequently asked ques- tions about their interpretation, utility, and application.

Recent global decline in endorheic basin water storages.

Abstract: Endorheic (hydrologically landlocked) basins spatially concur with arid/semi-arid climates. Given limited precipitation but high potential evaporation, their water storage is vulnerable to subtle flux perturbations, which are exacerbated by global warming and human activities. Increasing regional evidence suggests a probably recent net decline in endorheic water storage, but this remains unquantified at a global scale. By integrating satellite observations and hydrological modelling, we reveal that during 2002–2016 the global endorheic system experienced a widespread water loss of about 106.3 Gt yr−1, attributed to comparable losses in surface water, soil moisture and groundwater. This decadal decline, disparate from water storage fluctuations in exorheic basins, appears less sensitive to El Nino–Southern Oscillation-driven climate variability, which implies a possible response to longer-term climate conditions and human water management. In the mass-conserved hydrosphere, such an endorheic water loss not only exacerbates local water stress, but also imposes excess water on exorheic basins, leading to a potential sea level rise that matches the contribution of nearly half of the land glacier retreat (excluding Greenland and Antarctica). Given these dual ramifications, we suggest the necessity for long-term monitoring of water storage variation in the global endorheic system and the inclusion of its net contribution to future sea level budgeting.