407 research outputs found

    Synergies and trade-offs between energy-efficient urbanization and health

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    Energy-efficient urbanization and public health pose major development challenges for India. While both issues are intensively studied, their interaction is not well understood. Here we explore the relationship between urban infrastructures, public health, and household-related emissions, identifying potential synergies and trade-offs of specific interventions by analyzing nationally representative household surveys from 2005 and 2012. Our analysis confirms previous characterizations of the environmental-health transition, but also points to an important role of energy use and urbanization as modifiers of this transition. We find that non-motorized transport may prove a sweet spot for development, as its use is associated with lower emissions and better public health in cities. Urbanization and improved access to basic services correlate with lower short-term morbidity (STM), such as fever, cough and diarrhea. Our analysis suggests that a 10% increase in urbanization from current levels and concurrent improvement in access to modern cooking and clean water could lower STM for 2.4 million people. This would be associated with a modest increase in electricity related emissions of 84 ktCO2e annually. Promoting energy-efficient mobility systems, for instance by a 10% increase in bicycling could lower chronic diseases, like diabetes and cardio-vascular diseases, for 0.3 million people while also abating emissions. These findings provide empirical evidence to validate that energy-efficient and sustainable urbanization can address both public health and climate change challenges simultaneously

    Discourses of climate delay

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    ‘Discourses of climate delay’ pervade current debates on climate action. These discourses accept the existence of climate change, but justify inaction or inadequate efforts. In contemporary discussions on what actions should be taken, by whom and how fast, proponents of climate delay would argue for minimal action or action taken by others. They focus attention on the negative social effects of climate policies and raise doubt that mitigation is possible. Here, we outline the common features of climate delay discourses and provide a guide to identifying them

    Higher spin fermions in the BTZ black hole

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    Recently it has been shown that the wave equations of bosonic higher spin fields in the BTZ background can be solved exactly. In this work we extend this analysis to fermionic higher spin fields. We solve the wave equations for arbitrary half-integer spin fields in the BTZ black hole background and obtain exact expressions for their quasinormal modes. These quasinormal modes are shown to agree precisely with the poles of the corresponding two point function in the dual conformal field theory as predicted by the AdS/CFT correspondence. We also obtain an expression for the 1-loop determinant in terms of the quasinormal modes and show it agrees with that obtained by integrating the heat kernel found by group theoretic methods.Comment: 29 page

    Climate action for health and wellbeing in cities: a protocol for the systematic development of a database of peer-reviewed studies using machine learning methods [version 1; peer review: awaiting peer review]

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    Home Browse Climate action for health and wellbeing in cities: a protocol for... ALL METRICS 99 VIEWS 11 DOWNLOADS Get PDF Get XML Cite Export Track Email Share ▬ STUDY PROTOCOL Climate action for health and wellbeing in cities: a protocol for the systematic development of a database of peer-reviewed studies using machine learning methods [version 1; peer review: awaiting peer review] Kristine Belesova https://orcid.org/0000-0002-6160-50411, Max Callaghan https://orcid.org/0000-0001-8292-87582, Jan C Minx https://orcid.org/0000-0002-2862-01782, Felix Creutzig2, Catalina Turcu https://orcid.org/0000-0003-2663-25863, Emma Hutchinson1, James Milner1, Melanie Crane https://orcid.org/0000-0002-3058-22114, Andy Haines https://orcid.org/0000-0002-8053-46051, Michael Davies5, Paul Wilkinson1 Author details 1 Department of Public Health, Environments and Society and Centre on Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, WC1H 9SH, UK 2 Mercator Research Institute on Global Commons and Climate Change, Berlin, 10829, Germany 3 Bartlett School of Planning, University College London, London, WC1H 0QB, UK 4 Charles Perkins Centre, Sydney School of Public Health, University of Sydney, Sydney, Australia 5 Bartlett School Environment, Energy & Resources, University College London, London, WC1H 0QB, UK Kristine Belesova Roles: Conceptualization, Data Curation, Investigation, Methodology, Supervision, Writing – Original Draft Preparation, Writing – Review & Editing Max Callaghan Roles: Data Curation, Investigation, Methodology, Software, Writing – Review & Editing Jan C Minx Roles: Conceptualization, Investigation, Methodology, Software, Writing – Review & Editing Felix Creutzig Roles: Conceptualization, Investigation, Methodology, Software, Writing – Review & Editing Catalina Turcu Roles: Investigation, Methodology, Writing – Review & Editing Emma Hutchinson Roles: Investigation, Methodology, Writing – Review & Editing James Milner Roles: Methodology, Writing – Review & Editing Melanie Crane Roles: Methodology, Writing – Review & Editing Andy Haines Roles: Conceptualization, Funding Acquisition, Methodology, Supervision, Writing – Review & Editing Michael Davies Roles: Conceptualization, Funding Acquisition, Methodology, Writing – Review & Editing Paul Wilkinson Roles: Conceptualization, Funding Acquisition, Methodology, Supervision, Writing – Review & Editing Abstract Cities produce more than 70% of global greenhouse gas emissions. Action by cities is therefore crucial for climate change mitigation as well as for safeguarding the health and wellbeing of their populations under climate change. Many city governments have made ambitious commitments to climate change mitigation and adaptation and implemented a range of actions to address them. However, a systematic record and synthesis of the findings of evaluations of the effect of such actions on human health and wellbeing is currently lacking. This, in turn, impedes the development of robust knowledge on what constitutes high-impact climate actions of benefit to human health and wellbeing, which can inform future action plans, their implementation and scale-up. The development of a systematic record of studies reporting climate and health actions in cities is made challenging by the broad landscape of relevant literature scattered across many disciplines and sectors, which is challenging to effectively consolidate using traditional literature review methods. This protocol reports an innovative approach for the systematic development of a database of studies of climate change mitigation and adaptation actions implemented in cities, and their benefits (or disbenefits) for human health and wellbeing, derived from peer-reviewed academic literature. Our approach draws on extensive tailored search strategies and machine learning methods for article classification and tagging to generate a database for subsequent systematic reviews addressing questions of importance to urban decision-makers on climate actions in cities for human health and wellbeing

    Urban energy exchanges monitoring from space

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    One important challenge facing the urbanization and global environmental change community is to understand the relation between urban form, energy use and carbon emissions. Missing from the current literature are scientific assessments that evaluate the impacts of different urban spatial units on energy fluxes; yet, this type of analysis is needed by urban planners, who recognize that local scale zoning affects energy consumption and local climate. However, satellite-based estimation of urban energy fluxes at neighbourhood scale is still a challenge. Here we show the potential of the current satellite missions to retrieve urban energy budget, supported by meteorological observations and evaluated by direct flux measurements. We found an agreement within 5% between satellite and in-situ derived net all-wave radiation; and identified that wall facet fraction and urban materials type are the most important parameters for estimating heat storage of the urban canopy. The satellite approaches were found to underestimate measured turbulent heat fluxes, with sensible heat flux being most sensitive to surface temperature variation (-64.1, +69.3 W m-2 for ±2 K perturbation); and also underestimate anthropogenic heat flux. However, reasonable spatial patterns are obtained for the latter allowing hot-spots to be identified, therefore supporting both urban planning and urban climate modelling

    The Large N 't Hooft Limit of Kazama-Suzuki Model

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    We consider N=2 Kazama-Suzuki model on CP^N=SU(N+1)/SU(N)xU(1). It is known that the N=2 current algebra for the supersymmetric WZW model, at level k, is a nonlinear algebra. The N=2 W_3 algebra corresponding to N=2 was recovered from the generalized GKO coset construction previously. For N=4, we construct one of the higher spin currents, in N=2 W_5 algebra, with spins (2, 5/2, 5/2, 3). The self-coupling constant in the operator product expansion of this current and itself depends on N as well as k explicitly. We also observe a new higher spin primary current of spins (3, 7/2, 7/2, 4). From the behaviors of N=2, 4 cases, we expect the operator product expansion of the lowest higher spin current and itself in N=2 W_{N+1} algebra. By taking the large (N, k) limit on the various operator product expansions in components, we reproduce, at the linear order, the corresponding operator product expansions in N=2 classical W_{\infty}^{cl}[\lambda] algebra which is the asymptotic symmetry of the higher spin AdS_3 supergravity found recently.Comment: 44 pages; the two typos in the first paragraph of page 23 corrected and to appear in JHE

    Urbanization, processed foods, and eating out in India

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    Urban consumption of processed and fast foods is a challenge to nutrition security. Observed differences in urban versus rural consumption are commonly attributed to higher income levels in urban areas. Yet, there is still no clear understanding of why and how urban dwellers consume differently. Using India as a case study, we analyze expenditures on processed foods and consumption of food away from home (FAFH) of urban, metropolitan, and rural populations using OLS regression models. We show that urban households spend more on processed foods and consume more FAFH than rural households. Most of this difference can be attributed to differing socio-economic and demographic factors, such as higher income, or smaller urban household size. However, even after controlling for these factors, we find differences not only between rural and urban areas but also between different urban areas: households in large metropolitan areas consume more than households in smaller non-metropolitan urban areas. These inter-urban variations suggest that the dichotomy of urban versus rural consumption does not adequately capture the full spectrum of food consumption complexities. Our findings indicate that urbanization is affecting how people consume food beyond shaping their socio-economic and demographic status. We also highlight the need to account for the role of urbanization—beyond an urban-rural dichotomy—when addressing the challenges associated with changing food consumption patterns
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