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41.
The social cost of carbon – i.e., the marginal present-value cost imposed by greenhouse gas emissions – is determined by a complex interaction between factual assumptions, modeling methods, and value judgments. Among the most crucial factors is society's willingness to tolerate potentially catastrophic environmental risks. To explore this issue, the present analysis employs a stochastic climate–economy model that accounts for uncertainties in baseline economic growth, baseline emissions, greenhouse gas mitigation costs, carbon cycling, climate sensitivity, and climate change damages. In this model, preferences are specified to reflect the high degree of risk aversion revealed by private investment decisions, signaled by the large observed gap between the average rates of return paid by safe and risky financial instruments. In contrast, most climate–economy models assume much lower risk aversion. Given high risk aversion, the analysis finds that investment in climate stabilization yields especially large net benefits by forestalling low-probability threats to long-run human well-being. Accordingly, the social cost of carbon attains the markedly high value of $25,700 per metric ton of carbon dioxide in a baseline scenario in which emissions are unregulated. This value falls to just $4 per ton as the stringency of control measures is successively increased. These results cast doubt on the idea that the social cost of carbon takes on a uniquely defined, objective value that is independent of policy decisions. This does not, however, rule out the use of carbon prices to achieve the benefits of climate stabilization using least-cost mitigation measures.  相似文献   
42.
The possibility of extreme sea-level rise is one of the commonly cited reasons for concern about climate change. Major increases in sea level would likely be driven by the melting or collapse of major ice sheets. This possibility has implications for the social cost of carbon dioxide, which is a key policy value as well as a useful summary measure of damage caused by greenhouse gas emissions.This paper extends earlier work on the importance of low-probability, high-impact events for the social cost of carbon dioxide to incorporate the possibility of extreme sea-level rise.To estimate its impact, an integrated assessment model is used, which allows a probabilistic assessment of climate change damages based on the linkages between the economic and climate systems. In the model, the generic discontinuity damage is replaced with the possibility of large-scale damage from factors that are taken to be correlated with temperature rise and, crucially for this paper, explicit consideration of extreme sea-level rise.Estimates of the amount of increase in the social cost of carbon dioxide that can be expected from incorporating extreme sea-level rise show that the increase is significant, though not especially large in percentage terms.The paper contributes to the literature of how to represent uncertain climate impacts in integrated assessment models and the associated estimation of the social cost of carbon dioxide.  相似文献   
43.
Humanity faces a major global challenge in achieving wellbeing for all, while simultaneously ensuring that the biophysical processes and ecosystem services that underpin wellbeing are exploited within scientifically informed boundaries of sustainability. We propose a framework for defining the safe and just operating space for humanity that integrates social wellbeing into the original planetary boundaries concept (Rockström et al., 2009a,b) for application at regional scales. We argue that such a framework can: (1) increase the policy impact of the boundaries concept as most governance takes place at the regional rather than planetary scale; (2) contribute to the understanding and dissemination of complexity thinking throughout governance and policy-making; (3) act as a powerful metaphor and communication tool for regional equity and sustainability. We demonstrate the approach in two rural Chinese localities where we define the safe and just operating space that lies between an environmental ceiling and a social foundation from analysis of time series drawn from monitored and palaeoecological data, and from social survey statistics respectively. Agricultural intensification has led to poverty reduction, though not eradicated it, but at the expense of environmental degradation. Currently, the environmental ceiling is exceeded for degraded water quality at both localities even though the least well-met social standards are for available piped water and sanitation. The conjunction of these social needs and environmental constraints around the issue of water access and quality illustrates the broader value of the safe and just operating space approach for sustainable development.  相似文献   
44.
地理信息系统已经成为商品走进人们的生活 ,它所具有的社会公共功能正引起人们越来越多的关注。  相似文献   
45.
In the past 125 years, more than 70 authors have published ideas for keeping time on Mars, describing how to divide the Martian day and Martian year into smaller units. The Martian prime meridian was established in the mid-19th century, and the design of the Martian clock has been standardised at least since the Viking missions of the 1970s. Scientists can tell time on Mars; however, despite the constant stream of data that is downlinked from Mars these days, there is still no standardised system for expressing the date on Mars. Establishing a standard epoch—at a specific time of year on Mars, and a specific Martian year—should be the next priority in Martian timekeeping as a minimal system required for the physical sciences. More elaborate ideas, including the number and length of weeks and months, and names thereto, can be deferred for the present, but may become important considerations in coming years.  相似文献   
46.
Social capital can enhance community resilience to environmental change. Productive and trusted relations among social actors and effectual social norms can help local residents share resources, information and risks. The main objective of our study is to understand the ways in which social attributes and risk considerations influence adoption of resilient economic measures by individuals for reducing potential losses due to catastrophic rainstorm and flooding. This article provides evidence from China on how social capital contributes to anticipatory adaptation to environmental change. The inquiry is based on structured interviews with local residents of Tianjin, a flood-prone port city in China, and a standard regression analysis. Findings show that the intention to make preparation increases with the levels of social expectation, social relationship, and institutional trust. Perceived risk and damage experience, however, have no significant impacts. This suggests that building social capacity and trust will be more effective in enhancing community resilience than merely increasing awareness of hazard risks. We call for greater efforts on strengthening the capacity of formal and informal communal institutions. The structural changes required, however, are challenging.  相似文献   
47.
This research addresses recent environmental governance in Bolivia through its relations to indigeneity and respatializations. It introduces and develops the concept of “speaking like an indigenous state” to examine the Bolivian state’s recent use of a pair of indigenous linguistic concepts, Living Well and Earth Mother, representing the identities of citizens and their rights to resources and livelihoods. State relations to indigenous social movements highlight the use of Living Well and Earth Mother concepts through accommodation, resistance, and protaganism. Six active issues of environmental governance are examined: (1) climate change and justice movement; (2) agrarian reform, agrobiodiversity, and food justice; (3) water resources; (4) indigenous territories; (5) Protected Areas; and (6) extractive industries (mining, hydrocarbons). The usages of Living Well and Earth Mother show versatility as they have been mobilized in the respatializing of the politics and social-power dynamics of environmental issues at scales of the state, global and international institutions, and community and local levels. Analysis also reveals deployment of Living Well and Earth Mother that is discursively influential and yet conceptually reduced and unevenly applied, thus suggesting a characteristic of verisimilitude. My analysis determines that respatialization at various levels, including territorial transitions of sub-national regional spaces, are associated with the heightened articulation of environmental governance through indigeneity and “speaking like an indigenous state” amid resource nationalism. Linkages and logics operating within this conjuncture differ from the prevailing interpretation of the Bolivian state’s use of Living Well and Earth Mother as solely an unwitting contradiction or instrumentalist camouflage.  相似文献   
48.
To-date geographical research on encounters has primarily comprised observation of naturalistic settings (both micro publics and everyday public spaces) or narrative accounts of encounters generated by conventional methods, this paper focuses on a contrived spatial experiment to create meaningful contact across difference. Inspired by, and drawing on insights from, Architecture – a discipline relatively neglected by geographers in recent times – we use a creative form of spatial play to stimulate groups of people to explore their differences and to develop shared understandings. Whereas previous studies have identified the importance of material objects in art projects and home spaces in mediating relations between people, surprisingly little attention has been paid to the physical configuration of space in work on encounters, despite the fact that geography is a spatial discipline. Here, we engage directly with the role of the form and function of space. Our spatial experiments demonstrate how paying attention to the materiality of micro-spaces rather than social relations alone, can provide insights into the generation of positive interactions by contributing to a greater understanding of how meaningful encounters happen, and what can be done to facilitate them. Specifically, by exploring the size and configuration of space, issues of ownership and surveillance, the relationship between primary and secondary space, and aural architecture this research identifies how working together to create a shared private or intimate space – might facilitate a sense of empowerment and the production of social relations characterised by democracy and inclusion.  相似文献   
49.
Recent advances in geotagging, sharing and automatically analyzing online content from Social Networking Sites (SNS) offer unprecedented opportunities for the analysis of human-nature interactions. Previous studies in this field, however, offer limited insights regarding the benefits of automated content analysis especially at large scales, biases arising from the selection of SNS sources, and the predictive power of visitation models based on SNS data. We explore quantitative and qualitative aspects related to intensity, interests and sentiments associated with on-site experiences in 568 protected areas in Israel and the Palestinian Authority. We analyze counts and content of >100,000 photographs and tweets from four different SNSs, calibrate visitation models and predict visitation in unmonitored sites, cluster sites based on the typology of human-nature interactions reflected in online photographs, and characterize the polarity of sentiments associated with experiences in individual sites and clusters thereof. We find benefits in combining data from multiple sources and controlling for biases related to sites’ photogenicity and type of human-nature interactions. Our results suggest that current best estimates of visitation in unmonitored sites underestimate by 39% the actual number of visits. We discuss how the techniques and findings in this study are applicable in the broader context of the management and conservation of sites of environmental or cultural interest.  相似文献   
50.
What are relevant urban development investment strategies for improving building energy efficiency (BEE) and decarbonizing the urban district heating supply in rapidly urbanizing China? Different trajectories of BEE and energy supply technologies are compared in the urban context in a northern Chinese city. Vigorous improvement of BEE will significantly enhance the prospective financial capacity to facilitate deployment of backstop technologies (e.g. carbon capture and storage) in order to decarbonize the energy supply and achieve the long-term targets of low-carbon buildings. Carbon finance instruments should be used to facilitate public policy to accompany the necessary transition in the urban development process. The government-run efficiency procurement scheme will overcome the problem of insufficient incentive and high transaction costs associated with individual Clean Development Mechanism projects. Appropriate investment strategies (allocation of financial resources over the time frame) will allow local governments to harness the large potentials of carbon emissions mitigation while minimizing the risk of long-term technical lock-in in the built environment in Chinese cities.  相似文献   
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