Ignorance can be evolutionarily beneficial

Information is increasingly being viewed as a resource used by organisms to increase their fitness. Indeed, it has been formally shown that there is a sensible way to assign a reproductive value to information and it is non-negative. However, all of this work assumed that information collection is cost-free. Here, we account for such a cost and provide conditions for when the reproductive value of information will be negative. In these instances, counter-intuitively, it is in the interest of the organism to remain ignorant. We link our results to empirical studies where Bayesian behaviour appears to break down in complex environments and provide an alternative explanation of lowered arousal thresholds in the evolution of sleep.Comment: 5 pages, submitte

Understanding and responding to danger from climate change: the role of key risks in the IPCC AR5

The IPCC’s Fifth Assessment Report (AR5) identifies key risks in a changing climate to inform judgments about danger from climate change and to empower responses. In this article, we introduce the innovations and implications of its approach, which extends analysis across sectors and regions, and consider relevance for future research and assessment. Across key risks in the AR5, we analyze the changing risk levels and potential for risk reduction over the next few decades, an era with some further committed warming, and in the second half of the 21st century and beyond, a longer-term era of climate options determined by the ambition of global mitigation. The key risk assessment underpins the IPCC’s conclusion that increasing magnitudes of warming increase the likelihood of severe, pervasive, and irreversible impacts. Here, we emphasize central challenges in understanding and communicating risks. These features include the importance of complex interactions in shaping risks, the need for rigorous expert judgment in evaluating risks, and the centrality of values, perceptions, and goals in determining both risks and responses

Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation: Special Report of the Intergovernmental Panel on Climate Change

This Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX) has been jointly coordinated by Working Groups I (WGI) and II (WGII) of the Intergovernmental Panel on Climate Change (IPCC). The report focuses on the relationship between climate change and extreme weather and climate events, the impacts of such events, and the strategies to manage the associated risks. The IPCC was jointly established in 1988 by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP), in particular to assess in a comprehensive, objective, and transparent manner all the relevant scientific, technical, and socioeconomic information to contribute in understanding the scientific basis of risk of human-induced climate change, the potential impacts, and the adaptation and mitigation options. Beginning in 1990, the IPCC has produced a series of Assessment Reports, Special Reports, Technical Papers, methodologies, and other key documents which have since become the standard references for policymakers and scientists.This Special Report, in particular, contributes to frame the challenge of dealing with extreme weather and climate events as an issue in decisionmaking under uncertainty, analyzing response in the context of risk management. The report consists of nine chapters, covering risk management; observed and projected changes in extreme weather and climate events; exposure and vulnerability to as well as losses resulting from such events; adaptation options from the local to the international scale; the role of sustainable development in modulating risks; and insights from specific case studies

Broad distribution of stick-slip events in Slowly Sheared Granular Media: Table-top production of a Gutenberg-Richter-like distribution

We monitor the stick-slip displacements of a very slowly driven moveable perforated top plate which interacts via shearing with a packing of identical glass beads confined in a tray. When driven at a constant stress rate, the distributions of large event displacements and energies triggered by the stick-slip instabilities exhibit power law responses reminiscent of the Gutenberg-Richter law for earthquakes. Small events are quasi-size independent, signaling crossover from single-bead transport to collective behavior.Comment: 10 pages, 3 figure

Production of the biosphere: integrating terrestrial and oceanic components,”

Integrating conceptually similar models of the growth of marine and terrestrial primary producers yielded an estimated global net primary production (NPP) of 104.9 petagrams of carbon per year, with roughly equal contributions from land and oceans. Approaches based on satellite indices of absorbed solar radiation indicate marked heterogeneity in NPP for both land and oceans, reflecting the influence of physical and ecological processes. The spatial and temporal distributions of ocean NPP are consistent with primary limitation by light, nutrients, and temperature. On land, water limitation imposes additional constraints. On land and ocean, progressive changes in NPP can result in altered carbon storage, although contrasts in mechanisms of carbon storage and rates of organic matter turnover result in a range of relations between carbon storage and changes in NPP

Primary Production of the Biosphere: Integrating Terrestrial and Oceanic Components

Integrating conceptually similar models of the growth of marine and terrestrial primary producers yielded an estimated global net primary production (NPP) of 104.9 petagrams of carbon per year, with roughly equal contributions from land and oceans. Approaches based on satellite indices of absorbed solar ra-diation indicate marked heterogeneity in NPP for both land and oceans, re-flecting the influence of physical and ecological processes. The spatial and temporal distributions of ocean NPP are consistent with primary limitation by light, nutrients, and temperature. On land, water limitation imposes additional constraints. On land and ocean, progressive changes in NPP can result in altered carbon storage, although contrasts in mechanisms of carbon storage and rates of organic matter turnover result in a range of relations between carbon storage and changes in NPP. Biological processes on land and in the oceans strongly affect the global carbon cycle on all time scales (1–4). In both component

The IPCC AR5 guidance note on consistent treatment of uncertainties: A common approach across the working groups

Evaluation and communication of the relative degree of certainty in assessment findings are key cross-cutting issues for the three Working Groups of the Intergovernmental Panel on Climate Change. A goal for the Fifth Assessment Report, which is currently under development, is the application of a common framework with associated calibrated uncertainty language that can be used to characterize findings of the assessment process. A guidance note for authors of the Fifth Assessment Report has been developed that describes this common approach and language, building upon the guidance employed in past Assessment Reports. Here, we introduce the main features of this guidance note, with a focus on how it has been designed for use by author teams. We also provide perspectives on considerations and challenges relevant to the application of this guidance in the contribution of each Working Group to the Fifth Assessment Report. Despite the wide spectrum of disciplines encompassed by the three Working Groups, we expect that the framework of the new uncertainties guidance will enable consistent communication of the degree of certainty in their policy-relevant assessment findings

Student Characteristics as Predictors of Teachers’ Implementation of a Kindergarten Readiness Program

Recent years have seen increasing numbers of classroom-based interventions designed to enhance the school readiness of at-risk preschoolers. Even the most comprehensive, well-designed programs can suffer from limited effectiveness due to low-frequency implementation by teachers. The current study presents findings from the Building Bridges project (BB), an integrated program targeting school readiness in Head Start and low-income child care centers. Previous studies have reported the role of teacher-level and program-level characteristics in predicting teacher implementation of an intervention. The present study examines the role of student characteristics—language and math ability, social skills, and behavioral functioning—in predicting implementation exposure. These associations were examined in the context of program type (Head Start, child care) and intervention condition (consultation, no consultation). 88 classrooms (41 Head Start, 47 child care) participated in the BB intervention. Implementation exposure was predicted by several distinct student characteristics. Teachers whose students exhibited poorer language skills implemented significantly more BB activities, a finding that was consistent across program types and intervention conditions. A marginally significant trend was identified for oppositional behavior when interacted with intervention group in that teachers whose students demonstrated higher rates of oppositional behavior implemented fewer intervention activities when they did not have a consultant. Teachers in child care centers with a BB consultant had higher rates of implementation than did teachers in all other groups. These findings provide important information regarding the student-level characteristics that should be evaluated in order to optimize implementation of an intervention