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.

Glacial Cycles and Astronomical Forcing

Abstract: Narrow spectral features in ocean sediment records offer strong evidence that the cycles of glaciation were driven by astronomical forces. Two million years ago, the cycles match the 41,000-year period of Earth's obliquity. This supports the Croll/Milankovitch theory, which attributes the cycles to variations in insolation. But for the past million years, the spectrum is dominated by a single 100,000-year feature and is a poor match to the predictions of insolation models. The spectrum can be accounted for by a theory that derives the cycles of glaciation from variations in the inclination of Earth's orbital plane.

Implications of fisheries-induced evolution for stock rebuilding and recovery

Abstract: Worldwide depletion of fish stocks has led fisheries managers to become increasingly concerned about rebuilding and recovery planning. To succeed, factors affecting recovery dynamics need to be understood, including the role of fisheries-induced evolution. Here we investigate a stock’s response to fishing followed by a harvest moratorium by analyzing an individual-based evolutionary model parameterized for Atlantic cod Gadus morhua from its northern range, representative of long-lived, late-maturing species. The model allows evolution of life-history processes including maturation, reproduction, and growth. It also incorporates environmental variability, phenotypic plasticity, and density-dependent feedbacks. Fisheries-induced evolution affects recovery in several ways. The first decades of recovery were dominated by demographic and density-dependent processes. Biomass rebuilding was only lightly influenced by fisheries-induced evolution, whereas other stock characteristics such as maturation age, spawning stock biomass, and recruitment were substantially affected, recovering to new demographic equilibria below their preharvest levels. This is because genetic traits took thousands of years to evolve back to preharvest levels, indicating that natural selection driving recovery of these traits is weaker than fisheries-induced selection was. Our results strengthen the case for proactive management of fisheries-induced evolution, as the restoration of genetic traits altered by fishing is slow and may even be impractical.

Policy Networks as Collective Action

Abstract: An important contribution to the policy sciences, and to interorganizational research in particular, has been the introduction of the so-called policy network approach. Despite the fact that this approach has produced a multitude of concepts, it still lacks a theoretical scaffold. In this article it is argued that simply to refer to something called “network theory” is an unsatisfactory solution. It is suggested that one way of advancing the policy network approach is to apply collective action theory and explicitly regard different empirical appearances of network concepts as expressions of collective action. Six tentative building blocks of such a theory are suggested. It is further argued that the policy network approach would benefit from incorporation into a broader analytical framework such as the Institutional Analysis and Development framework. Finally, it is concluded that such an incorporation would advance our ability to understand the processes of policymaking and thus to fulfill one of the old commitments of policy analysis, namely to contribute to the refinement of policymaking processes in society.