Showing papers on "Tipping point (climatology) published in 2008"

Tipping elements in the Earth's climate system

Abstract: The term "tipping point" commonly refers to a critical threshold at which a tiny perturbation can qualitatively alter the state or development of a system. Here we introduce the term "tipping element" to describe large-scale components of the Earth system that may pass a tipping point. We critically evaluate potential policy-relevant tipping elements in the climate system under anthropogenic forcing, drawing on the pertinent literature and a recent international workshop to compile a short list, and we assess where their tipping points lie. An expert elicitation is used to help rank their sensitivity to global warming and the uncertainty about the underlying physical mechanisms. Then we explain how, in principle, early warning systems could be established to detect the proximity of some tipping points.

Slowing down as an early warning signal for abrupt climate change

Abstract: In the Earth's history, periods of relatively stable climate have often been interrupted by sharp transitions to a contrasting state. One explanation for such events of abrupt change is that they happened when the earth system reached a critical tipping point. However, this remains hard to prove for events in the remote past, and it is even more difficult to predict if and when we might reach a tipping point for abrupt climate change in the future. Here, we analyze eight ancient abrupt climate shifts and show that they were all preceded by a characteristic slowing down of the fluctuations starting well before the actual shift. Such slowing down, measured as increased autocorrelation, can be mathematically shown to be a hallmark of tipping points. Therefore, our results imply independent empirical evidence for the idea that past abrupt shifts were associated with the passing of critical thresholds. Because the mechanism causing slowing down is fundamentally inherent to tipping points, it follows that our way to detect slowing down might be used as a universal early warning signal for upcoming catastrophic change. Because tipping points in ecosystems and other complex systems are notoriously hard to predict in other ways, this is a promising perspective.

Tipping and the Dynamics of Segregation

Abstract: Schelling (“Dynamic Models of Segregation,” Journal of Mathematical Sociology 1 (1971), 143–186) showed that extreme segregation can arise from social interactions in white preferences: once the minority share in a neighborhood exceeds a “tipping point,” all the whites leave. We use regression discontinuity methods and Census tract data from 1970 through 2000 to test for discontinuities in the dynamics of neighborhood racial composition. We find strong evidence that white population flows exhibit tipping-like behavior in most cities, with a distribution of tipping points ranging from 5% to 20% minority share. Tipping is prevalent both in the suburbs and near existing minority enclaves. In contrast to white population flows, there is little evidence of nonlinearities in rents or housing prices around the tipping point. Tipping points are higher in cities where whites have more tolerant racial attitudes.

Recent radical shifts of atmospheric circulations and rapid changes in Arctic climate system

Abstract: [1] Arctic climate system change has accelerated tremendously since the beginning of this century, and a strikingly extreme sea-ice loss occurred in summer 2007. However, the greenhouse-gas-emissions forcing has only increased gradually and the driving role in Arctic climate change of the positively-polarized Arctic/North Atlantic Oscillation (AO/NAO) trend has substantially weakened. Although various contributing factors have been examined, the fundamental physical process, which orchestrates these contributors to drive the acceleration and the latest extreme event, remains unknown. We report on drastic, systematic spatial changes in atmospheric circulations, showing a sudden jump from the conventional tri-polar AO/NAO to an unprecedented dipolar leading pattern, following accelerated northeastward shifts of the AO/NAO centers of action. These shifts provide an accelerating impetus for the recent rapid Arctic climate system changes, perhaps shedding light on recent arguments about a tipping point of global-warming-forced climate change in the Arctic. The radical spatial shift is a precursor to the observed extreme change event, demonstrating skilful information for future prediction.

Silurian global events - at the tipping point of climate change

Abstract: Mass extinction events affect a wide breadth of ecosystems and are one of the major driving mechanisms behind evolution, origination, and diversification of taxa. Such dramatic turnovers have therefore played a significant role in the history of life. The ‘major five’ mass extinctions (Raup and Sepkoski 1982) have received intense attention over the last 25 years, starting with the K-Pg impact hypothesis launched by Luis Alvarez and others in Science in 1980. By comparison, few studies have concerned the about sixty smaller-scale bioevents that are scattered throughout the last ca 543 million years (Barnes et al. 1995), although their architecture often resembles that of the large scale mass-extinctions and they therefore may hold important information relevant to events in general. The Silurian Period is the shortest time period of the entire Phanerozoic (~443-416 Ma) but yields a significant record of ocean-atmospherebiosphere changes. The period has traditionally been described as an environmentally and faunally stable period in Earth history – a greenhouse period with a moderate latitudinal climate gradient and impoverished marine faunas slowly recovering from the end-Ordovician mass extinction. It has more recently, however, been shown that the Silurian was no quieter than any other time interval during the Phanerozoic Eon, rather the opposite. The results of an immense number of studies, primarily in the fields of taxonomy, biostratigraphy and stable isotope stratigraphy clash fundamentally with the old view. The new studies have unequivocally shown that repeated marine biodiversity crises took place, affecting e.g. graptolites, conodonts, chitinozoans, acritarchs, brachiopods and reefs, and that these turnovers were closely linked to abrupt and significant changes in oceanography and the global carbon cycle. Accordingly, today the Silurian can be regarded as one of the most volatile periods of the entire Phanerozoic when considering the ocean-atmosphere system (Cramer and

Plan B 3.0 : Mobilizing to Save Civilization

Abstract: Le nouveau livre de Lester Brown. Il y a urgence a ce qu'il soit traduit…et qu'il soit lu… Table des matieres 1. Entering a New World (pdf) A Massive Market Failure Environment and Civilization China : Why the Existing Economic Model Will Fail Mounting Stresses, Failing States A Civilizational Tipping Point Plan B—A Plan of Hope Chapter 1 Data (xls) PART I. A CIVILIZATION IN TROUBLE 2. Deteriorating Oil and Food Security (pdf) The Coming Decline of Oil The (…)

Creating an Earth Atmospheric Trust.

Abstract: STABILIZING CONCENTRATIONS OF GREENHOUSE GASES IN THE EARTH’S ATMOSPHERE AT A level that will control climate change will require drastic departures from business as usual. Here, we introduce one response to this challenge that may seem visionary or idealistic today, but that could become realistic once we reach a tipping point that opens a window of opportunity for embracing major changes. The core of this system is the idea of a common asset trust. Trusts are widely used and well-developed legal mechanisms designed to protect and manage assets on behalf of specific beneficiaries. Extending this idea to the management and protection of a global commons, such as the atmosphere, is a new but straightforward extension of this idea. Because the atmosphere is global, the Earth Atmospheric Trust would be global in scope; however, initial implementation at a regional or national scale may be necessary. We provide an outline of the steps that must be taken to create and manage such a system. (i) Create a global cap-and-trade system for all greenhouse gas emissions. We believe a cap-andtrade system is preferable to a tax, because the major goal is to cap and reduce the quantity of emissions in a predictable way. Caps set quantity and allow price to vary; taxes set price and allow quantity to vary.

Extreme Events, Global Warming, and Insurance-Linked Securities: How to Trigger the “Tipping Point”

Abstract: Large-scale disasters have occurred at an accelerated rhythm in the past 5 years. Further, the continuous increase of exposed values in high-risk areas and the potential impact of global warming on the intensity of weather-related events shall accelerate the number and increase the scale of mega-catastrophes in the near future. That is a new era for catastrophe risk management that calls for the development of new solutions, in complement to the traditional insurance and reinsurance. The authors discuss some of the main drivers of the radical shift that happened in the insurance-linked securities (ILS) market after the 2005 hurricane season in the Atlantic basin, which has rapidly become one of the world peak zones in terms of exposure. They explain why, despite this very encouraging evolution, the market has not expanded more (contrary to credit derivatives for instance). They propose three complementary ways to increase interest in these instruments that could effectively trigger the tipping point toward a much more significant volume of capital entering the ILS market: (1) increasing investors' interest through tranching, (2) addressing the basis risk challenge through index-based derivatives, and (3) innovating through the development of new products; the authors introduce the concept of derivative solutions based on equity volatility dispersion.

Governments, Civilians, and the Evolution of Insurgency: Modeling the Early Dynamics of Insurgencies

Abstract: This paper models the early dynamics of insurgency using an agent-based computer simulation of civilians, insurgents, and soldiers. In the simulation, insurgents choose to attack government forces, which then strike back. Such government counterattacks may result in the capture or killing of insurgents, may make nearby civilians afraid to become insurgents, but may also increase the anger of surrounding civilians if there is significant collateral damage. If civilians become angry enough, they become new insurgents. I simulate the dynamics of these interactions, focusing on the effectiveness of government forces at capturing insurgents vs. their accuracy in avoiding collateral damage. The simulations suggest that accuracy (avoidance of collateral damage) is more important for the long-term defeat of insurgency than is effectiveness at capturing insurgents in any given counterattack. There also may be a critical 'tipping point' for accuracy below which the length of insurgencies increases dramatically. The dynamics of how insurgencies grow or decline in response to various combinations of government accuracy and effectiveness illustrate the tradeoffs faced by governments in dealing with the early stages of an insurgency.

Tipping Point Forewarnings in Climate Change Communication: Some Implications of an Emerging Trend

Abstract: Prominent British and American sources now seek to structure public understanding of climate change by issuing “tipping point” forewarnings of danger with increasing frequency. This emerging trend announces a shift in the way we are likely to perceive and respond to climate change dangers. This paper reviews key statements to suggest a significant dimension of this trend is its enrollment of epidemiological terminology to communicate urgent and uncertain threats. First, key events in the popular employment of epidemiological and public health models of explanation are reviewed. Second, the author discusses the climate change “debate” to illuminate the limitations involved in treating climate change as a public issue detached from other problems involving atmospheric science. Third, the author reconstructs the tipping point tendency in this context. The essay concludes that the use of this concept signals a broader trend toward epidemiological models of explanation likely to activate public health styles o...

Managing Tipping Point Dynamics in Complex Construction Projects

Abstract: Complex construction projects are vulnerable to tipping points. Tipping points are conditions that, when crossed, cause system behaviors to radically change performance. Previous research identified tipping point dynamics as capable of explaining the failure of some nuclear power plant construction projects. These dynamics can also threaten the success of other large, complex construction projects. The current work uses a dynamic project model to test policies for managing tipping point dynamics. The Limerick Unit 2 nuclear power plant project is used to test model usefulness. Sensitivity analysis reveals the rework fraction, strength of subsystem interdependence, and sensitivity of the project to schedule pressure as potential high-leverage points for policy design. The model is used to test policies for managing tipping points that were used to complete the Limerick Unit 2 nuclear power plant after a tipping point threatened project completion. Implications for construction project design and management and research opportunities are discussed.

Empirics of Strategic Interdependence: The Case of the Racial Tipping Point

Abstract: The Schelling model of a “tipping point” in racial segregation, in which whites flee a neighborhood once a threshold of nonwhites is reached, is a canonical model of strategic interdependence. The idea of “tipping” explaining segregation is widely accepted in the academic literature and popular media. I use census tract data for metropolitan areas of the US from 1970 to 2000 to test the predictions of the Schelling model and find that this particular model of strategic interaction largely fails the tests. There is more “white flight” out of neighborhoods with a high initial share of whites than out of more racially mixed neighborhoods.

The Green Library Movement: An Overview and Beyond - eScholarship

Abstract: The creation of green libraries is approaching a tipping point, generating a Green Library Movement, which is comprised of librarians, libraries, cities, towns, college and university campuses committed to greening libraries and reducing their environmental impact. Constructing a green library building using a performance standard like LEED is a way some libraries are choosing to become green and sustainable. Environmental challenges like energy depletion and climate change will influence the type of information resources and programs libraries will provide to their communities.

Rifts and Shifts: Getting to the Root of Environmental Crises

Abstract: Humans depend on functioning ecosystems to sustain themselves, and their actions affect those same ecosystems. As a result, there is a necessary "metabolic interaction" between humans and the earth, which influences both natural and social history. Increasingly, the state of nature is being defined by the operations of the capitalist system, as anthropogenic forces are altering the global environment on a scale that is unprecedented. The global climate is rapidly changing due to the burning of fossil fuels and deforestation. No area of the world's ocean is unaffected by human influence, as the accumulation of carbon, fertilizer runoff, and overfishing undermine biodiversity and the natural services that it provides. The Millennium Ecosystem Assessment documents how over two-thirds of the world's ecosystems are overexploited and polluted. Environmental problems are increasingly interrelated. James Hansen, the leading climatologist in the United States, warns that we are dangerously close to pushing the planet past its tipping point, setting off cascading environmental problems that will radically alter the conditions of naturei»?This article can also be found at the Monthly Review website, where most recent articles are published in full.Click here to purchase a PDF version of this article at the Monthly Review website.

The Green Library Movement: An Overview and Beyond

Abstract: The creation of green libraries is approaching a tipping point, generating a Green Library Movement, which is comprised of librarians, libraries, cities, towns, college and university campuses committed to greening libraries and reducing their environmental impact. Constructing a green library building using a performance standard like LEED is a way some libraries are choosing to become green and sustainable. Environmental challenges like energy depletion and climate change will influence the type of information resources and programs libraries will provide to their communities.

At the tipping point: accomplishing population-wide sodium reduction in the United States.

Abstract: THE JOurNaL Of CLiNiCaL HypErTENsiON 7 a convergence of recent policy recommendations and scientific advances has set the stage for renewed, aggressive, and hopefully effective efforts to reduce dietary sodium intake in the general population. The objective of this paper is to summarize the scientific rationale for populationwide sodium reduction, review recent scientific and policy developments, and offer guidance to health care providers.

Are mixed neighborhoods always unstable? Two-sided and one-sided tipping

Abstract: Author(s): Card, D; Mas, A; Rothstein, J | Abstract: Racial segregation is a defining feature of urban neighborhoods in the United States. A large body of social science research has established that black children raised in more segregated areas have worse outcomes' including lower levels of completed education' lower test scores' lower marriage rates' lower employment and earnings' and higher crime rates (e.g.' Massey and Denton 1993; Cutler and Glaeser 1997). Though researchers still do not agree about the extent to which the observed correlations between segregation and these outcomes are causal' a major goal of public policy over the past four decades has been to reduce racial segregation in neighborhoods' schools' and workplaces. The efficacy of integration policies depends critically on the underlying forces that have led to and sustained segregation. While institutional and legal forces played an important part in enforcing segregation in the Jim Crow era' many analysts have argued that the preferences of white families for neighborhoods with a lower fraction of minority residents are the driving force in explaining segregation today (e.g.' Cutler and Glaeser 1997). In a highly influential contribution' Schelling (1971) showed that even when most whites have relatively weak preferences for lower minority shares' social interactions in preferences are likely to lead to a fully segregated equilibrium. In Schelling's model (and in more recent theoretical studies' including Brock and Durlauf 2001 and Glaeser and Scheinkman 2003)' a given neighborhood can have multiple equilibria. Holding constant conditions in the rest of the city' the neighborhood could either be (nearly) 100 percent white' nearly 100 percent minority' or a mixture. Importantly' however' in Schelling's formulation the mixed equilibrium is inherently unstable: Adding a few extra minority families sets off a chain of departures by whites that only ends once all the white families have left. Likewise' adding a few white families sets off a chain of departures by minority families that ultimately lead to an all-white neighborhood. In this chapter we use data on the evolution of census tracts from 1970 until 2000 to investigate whether integrated neighborhoods are sustainable in the long run' or whether they are inherently unstable and destined to become either 100 percent minority or 100 percent white. Our analysis builds on a companion paper (Card' Mas' and Rothstein 2008b; hereafter CMR)' in which we found that most major metropolitan areas are characterized by a city-specific "tipping point'" a level of the minority share in a neighborhood that once exceeded sets off a rapid exodus of the white population. To illustrate this finding' Figure 14.1 plots mean percentage changes in the white population of Chicago census tracts from 1970 to 1980 against the tract's minority share in 1970.1 The graph shows clear evidence of a critical threshold at around a 5 percent minority share: neighborhoods with 1970 minority shares below this threshold experienced gains in their white populations over the next decade' while those with initial shares above the threshold experienced substantial outflows. These patterns hold on average for a broad sample of U.S. cities in each of the past three decades. Most common understandings of neighborhood tipping envision a transition from virtually all-white composition to virtually 100 percent minority. This is certainly the historical experience. Northern cities had relatively low numbers of racial minorities in 1940' but as African Americans migrated from the South' many neighborhoods within these cities tipped from all-white to nearly all-black. This process has been interpreted by many analysts as evidence of the inherent instability in integrated neighborhoods predicted by Schelling's model. According to this interpretation' the mixed neighborhoods observed today (say with a 10 or 15% minority share) are in the process of transitioning to an all-minority status. Nevertheless' a class of alternative models-including the one developed in CMR-suggests that mixed neighborhoods can survive in the long run' so long as the minority share does not exceed a critical tipping point. In these alternative models' the tipping point is not a "knife edge" temporary equilibrium that is destined to fail. Rather' the tipping point represents a boundary point. Neighborhoods with minority shares below this level can remain integrated; but once the tipping point is exceeded' the neighborhood will quickly move to a nearly 100% minority equilibrium. The distinction between these views of tipping is quite important for policy purposes. Under Schelling's model' planners hoping to create and maintain vital integrated neighborhoods must fight continuously against market forces' which are always pulling the neighborhood toward complete segregation. By contrast' under the alternative models' a neighborhood can remain stable with a moderate minority share. The alternative models provide a justification for policies meant to encourage racial and ethnic diversity in neighborhoods. If integrated neighborhoods are inherently unstable' however' these efforts are likely to have little long run effect on the degree of racial segregation in a city. We attempt to distinguish between alternative models of tipping by investigating whether integrated neighborhoods with minority shares below the tipping point tend to experience rapid minority flight (as predicted by Schelling's original model) or whether they can remain integrated over several decades. The answer to this question is of growing importance because tipping points appear to have risen. If neighborhoods below the tipping point are stable' increases in the tipping point can lead to increasingly integrated neighborhoods' all else equal. CMR documented average tipping points in the range of a 13 percent minority share over the 1970-1990 period' with slight increases over time. This contrasts sharply with earlier experience' where neighborhoods in many cities seemed prone to tip in response to even a small (1 or 2 percent) minority presence. Applying the same methods as in CMR' we estimated the tipping points for three large Midwestern cities (Chicago' Cleveland' and Detroit) for the 1940-1970 period. Figure 14.2 shows the evolution of the tipping points in these cities since 1940.2 In two of the three cities' the tipping point was near zero in 1940 and 1950 (in the third' Cleveland' it was near 10 percent in 1940 but fell to near zero in 1950)' and in each case it rose substantially by 1970 and farther in the later years. Although 1940 and 1950 tipping points are not available for other cities' the figure also shows that the average tipping point across all large cities in the country was around 12 percent in 1970 and rose somewhat over the next two decades. Changes in tipping points have been accompanied by dramatic changes in the cross-sectional distribution of minority shares across census tracts. Figure 14.3 shows the distribution of tract minority shares for the pooled sample of tracts from the three cities in 1950' 1970' 1980' and 1990. In 1950' this distribution is highly bimodal' with many allwhite neighborhoods' a few all-minority (almost entirely black) neighborhoods' and essentially no integrated neighborhoods. This distribution would be expected from a tipping point at a very low minority share. In more recent decades' we see two key changes. First' there are more neighborhoods with very high minority shares' as each city's black (and more recently Hispanic) population expanded over the second half of the twentieth century. Second' we increasingly see neighborhoods with intermediate minority shares' neither all-white nor all-minority. Many of these integrated neighborhoods have minority shares below the (now higher) tipping points. The histograms suggest the possibility that neighborhoods below the tipping points might be stable' though because they represent only cross-sections they are also consistent with instability of integrated tracts. In what follows we present a series of tests for the stability of neighborhoods with minority shares below the tipping points identified by CMR. We focus on the 1970 tipping point. As indicated in Figure 14.2' 1970 seems to represent the beginning of the modern era for this sort of analysis' with tipping points that resemble those seen in the 1980s and 1990s more closely than they do the lower tipping points observed in the 1940s and 1950s.3 Importantly for our purposes' a focus on 1970 allows us to observe neighborhoods' outcomes over a thirty-year period. We examine the racial/ethnic composition of census tracts in 1980' 1990' and 2000' relating this to a tract's location relative to the 1970 tipping point. Overall' we conclude that tipping is one-sided: while neighborhoods with minority shares above the 1970 tipping point appear to move toward high minority concentrations in later decades' those that remain below the tipping point are more stable' and show no indication of substantial minority flight. Copyright © 2011 University of Pennsylvania Press. All rights reserved.

Foreign Direct Investment in Developing Countries: have we reached a policy ‘tipping point’?

Abstract: In the 1990s, around the world, government policies on fdi were unequivocally fdi -friendly. Numerous policy changes were enacted to make the investment climate more favourable to fdi. However, over the past few years a range of countries has enacted policy measures less favourable to fdi. Does this represent an overall shift in fdi policy thinking? And, if so, what are the current drivers of such a change? This paper discusses trends in contemporary fdi policy and the role played by prevailing narratives, actors and the changing context in shaping policy.

Research and Solutions: Think Systemically, Act Cooperatively: The Key to Reaching a Tipping Point for the Sustainability Movement in Higher Education

Abstract: This paper presents the growing trend in colleges and universities to incorporate a sustainability perspective as a social movement. It seeks to catalyze a broader discussion on how best to acceler...

Living the "Tipping Point": Concurrent Teacher Leader and Principal Preparation

Abstract: In a 2007 edition of the NCPEA Yearbook, Zigler and Allen allude to the principalship and its associated training as being at a "tipping point," a reference to Malcom Gladwell's (2000) book, The Tipping Point: How Little Things Can Make a Difference (Zigler & Allen, 2007). Gladwell elaborates on various ways that small changes, known as tipping points, cascade to a large impact. Zigler and Allen contend the current principal paradigm is too complex and that perhaps a shared leadership paradigm warrants consideration. They propose that this shared leadership may be a tipping point for future development in principal preparation programs. Wright State University's Department of Educational Leadership provides concurrent preparation of both principal and teacher leader candidates. Our teacher leadership program courses promote "training in skills such as team building, problem solving, and critical thinking [that] enhance teachers' capacities in their current classroom functions in conjunction with aiding administrative duties ... in which teachers can assist school administrators. These include, but are not limited to, mentoring new staff, participating in collaborative decision-making, designing and developing new curricula, and conducting staff development offerings" (Adams & Hambright, 2005, p. 90). We were pleased with our inclusion in the NCPEA Zigler and Allen article as a teacher leadership program exemplar (Zigler & Allen, 2007). To further expound on their tipping point theme, we want to describe past and present program improvement initiatives underscoring the tipping point premise. The History: Three Tipping Points Wright State University's Teacher Leader Program has supplied southwest Ohio schools with teacher leader graduates for over twenty-five years, and within that timeline, the program experienced several tipping points bringing about significant programmatic changes. The initial tipping point occurred when the program evolved from an initial off-campus professional development workshop provider model in the mid-1970s to a satellite graduate degree program delivery model in the late-1980s. The latter model intended to deliver requisite foundations and leadership coursework to aspiring principal certification-seeking candidates at various PK-12 satellite locations across our service area. In hindsight, the program moniker, "teacher leader," implied what Collay describes as "(t)he leader (principal) is the visionary and the followers (teachers) are unenlightened and dependent upon that vision (Collay, 2006, p. 137)." In other words, the principal led and the teachers followed. A second tipping point promoted program changes occurring in the early- to mid-1990s that essentially divorced the Teacher Leader Program from the principal preparatory track. Internal program leadership determined that teachers sought independence from any administrative-oriented responsibilities and teacher leadership capacities were best served within the confines of individual classrooms. The ensuing teacher leader program's title and mission thus implied teacher leaders primarily led students. The programming decisions meant that a standalone teacher leader program emerged separately from an educational leadership master's program geared for individuals specifically seeking administrative credentialing. Teacher Leader Program graduates could still eventually attain administrative certificates, but their route became burdened with additional courses following their degree attainment that their counterparts in the Educational Leadership Program completed during their studies. A recent critical juncture having a tripartite rationale prompted yet a third program tipping point. With the advent of program accreditation standards from the National Council for Accreditation of Teacher Education (NCATE) and the Educational Leadership Constituent Council (ELCC), streamlining program tracks was imperative in light of increased accountability measuring and reporting. …

The Green Library Movement: An Overview of Green Library Literature and Actions from 1979 to the Future of Green Libraries

Abstract: The creation of green libraries is approaching a tipping point, generating a Green Library Movement, which is comprised of librarians, libraries, cities, towns, college and university campuses committed to greening libraries and reducing their environmental impact. Constructing a green library building using a performance standard like LEED is a way some libraries are choosing to become green and sustainable. Environmental challenges like energy depletion and climate change will influence the type of information resources and programs libraries will provide to their communities. Keywords: Green Library Movement, green, stainable, libraries, programs, LEED, environment, peak oil, climate change TIME writer Bryan Walsh believes the year 2007 will be remembered as "the tipping point when public understanding of the existential threat of climate change reached critical mass" (Walsh, 2007, para. 1). Malcolm Gladwell (2000) in his bestselling book, The Tipping Point, explains that ideas and behaviors can spread like viruses (p. 7). Eventually the idea or behavior reaches a tipping point also known as "the critical mass, the threshold, the boiling point" (p. 12). In sociology the term tipping point refers to the moment when something previously unique becomes common (p. 12). Around the country the idea and behavior of creating green libraries is approaching a tipping point and transforming into a library movement. The Green Library Movement has been in existence for over 15 years. The Movement emerged in the early 1990s and gained popularity in the library profession around 2003. It is comprised of a growing number of librarians, libraries, cities, towns, college and university campuses committed to greening libraries by reducing their environmental impact on the planet. This innovation is happening by building green library buildings, by greening existing library facilities, providing green library services, and embracing environmentally supportive and sustainable practices within the library. Green Definitions Throughout this article the terms "green" and "sustainable" are used and need to be defined. In the Oxford English Dictionary (1989) the term "green" is defined as "pertaining to, or supporting environmentalism" (p. 811). The term "sustainable"relates to "forms of human economic activity and culture that do not lead to environmental degradation, esp. avoiding the long-term depletion of natural resources" (Oxford English, 2008). Green Library Literature The amount of information available on green libraries and green library practices is limited but continues to grow. The earliest articles on green libraries appeared in the 1990s. The Wilson Library Bulletin's February 1991 issue featured a special section on "Libraries and the Environment." James and Suzanne LeRue wrote the lead article entitled "The Green Librarian" (1991). In this article, the LeRues explained in detail how to be environmentally supportive at home and in the library. Three other articles were included in the special section. "Finding the Trees in the Forest: Environmental Information Sources" by Tom Watson (1991) pulled together a list of groups, agencies and publications that focused on the environment and environmental information. "Celebrating Earth Day all Year Long" by Linda Rome (1991) provided a history of Earth Day, as well as ideas on how to keep the public's attention on environmental issues all year. "Noise in the Library: Effects and Control" by Ann Eagan (1991) examined noise pollution in the library. The Viewpoint section of the February issue included an additional environmental article, "The Library as an Environmental Alternative (Among Other Things)" by Steven Smith (1991). Smith discussed the spatial limits of the library and nature, and the role libraries need to play in preserving both. The Wilson Library Bulletin environmental articles are significant because they were published shortly after the 20th anniversary of the original Earth Day celebration, which received an enormous amount of media coverage. …

Approaching the tipping point: climate risks, faith and political action

Abstract: Scientific and media reports have become enthralled by the apocalyptic overtones of climatic ‘tipping points’. These are thresholds after which a relatively small shift in the Earth system (e.g. melting Arctic perma-frost) has a big, sudden impact on the overall system. Related is the prospect of runaway or ‘irreversible’ global warming. But they have also revived an interest in the original sociological sense – i.e. tipping points in social and political movement. How do we relate the two? Given the possibility that certain catastrophic events may be unavoidable, climatic tipping points present a situation of global risk unlike any considered before. They introduce an element of radical uncertainty into the very value of taking action. In this paper I argue that ethical bases for taking action must think beyond thresholds assumed by calculations of traditional probabilities of risk such as the precautionary principle or cost-benefit analysis (or simply the assumption that ‘my actions will be meaningless unless this happens by this time’). I demonstrate this by reporting from an emerging political movement in the UK that is demonstrating precisely the value of risktaking in the ‘public sphere’ of non-violent direct action. Appropriately enough for (Hansen’s) reference to the question of redemption (below), theological insight may indeed have something to contribute here. For an ethics that places imperatives for faith in action prior to epistemic certainty (doing, in other words, comes before knowing) lies arguably at the root of many religious or otherwise utopian traditions.

Self-organized Natural Roads for Predicting Traffic Flow: A Sensitivity Study

Abstract: In this paper, we extended road-based topological analysis to both nationwide and urban road networks, and concentrated on a sensitivity study with respect to the formation of self-organized natural roads based on the Gestalt principle of good continuity. Both Annual Average Daily Traffic (AADT) and Global Positioning System (GPS) data were used to correlate with a series of ranking metrics including five centrality-based metrics and two PageRank metrics. It was found that there exists a tipping point from segment-based to road-based network topology in terms of correlation between ranking metrics and their traffic. To our big surprise, (1) this correlation is significantly improved if a selfish rather than utopian strategy is adopted in forming the self-organized natural roads, and (2) point-based metrics assigned by summation into individual roads tend to have a much better correlation with traffic flow than line-based metrics. These counter-intuitive surprising findings constitute emergent properties of self-organized natural roads, which are intelligent enough for predicting traffic flow, thus shedding substantial insights into the understanding of road networks and their traffic from the perspective of complex networks. Keywords: topological analysis, traffic flow, phase transition, small world, scale free, tipping point

Ecology: The Moment of Truth - An Introduction

Abstract: It is impossible to exaggerate the environmental problem facing humanity in the twenty-first century. Nearly fifteen years ago one of us observed: "We have only four decades left in which to gain control over our major environmental problems if we are to avoid irreversible ecological decline."1 Today, with a quarter-century still remaining in this projected time line, it appears to have been too optimistic. Available evidence now strongly suggests that under a regime of business as usual we could be facing an irrevocable "tipping point" with respect to climate change within a mere decade.2 Other crises such as species extinction (percentages of bird, mammal, and fish species "vulnerable or in immediate danger of extinction" are "now measured in double digits");3 the rapid depletion of the oceans' bounty; desertification; deforestation; air pollution; water shortages/pollution; soil degradation; the imminent peaking of world oil production (creating new geopolitical tensions); and a chronic world food crisis—all point to the fact that the planet as we know it and its ecosystems are stretched to the breaking point. The moment of truth for the earth and human civilization has arrivedThis article can also be found at the Monthly Review website, where most recent articles are published in full.Click here to purchase a PDF version of this article at the Monthly Review website.

Will we allow dentistry to be left behind? Principles underlying dental education and practice.

Abstract: It is a special pleasure to provide remarks at the opening of the Macy study convocation. This meeting is extraordinary and important for several reasons: the attendees are essentially all the leaders in dental education; our nation is approaching a tipping point with regard to changing the health

Viewpoint: Climate change and planning: carbon control and spatial regulation

Abstract: After a decade of false starts, the goal of radically reducing emissions of greenhouse gases, and particularly carbon dioxide, is rising up the political agenda. The renewed urgency of the 'carbon control' agenda reflects a tipping point in political, public and media acceptance of the reality of global warming, its human causes, and the future economic and social costs of inaction. Political commitment to carbon control is also

A Tipping Point Realized? Nuclear Proliferation in the Persian Gulf and Middle East

Abstract: The Persian Gulf and the wider Middle East are precariously perched on an uncertain nuclear threshold. Several regional states may be reconsidering their non-nuclear status. Iran's confrontation with the international community over its refusal to honour its obligations under the Nuclear Non-Proliferation Treaty is the overriding component states are viewing. Another element is Israel's nuclear program and its policy of preventing any regional state from threatening the Jewish state with nuclear weapons. Another complicating element in the strategic framework is a resurgent interest in nuclear energy. What is the security policy community to make of these dynamics in which proliferation, deterrence, extended deterrence, and conflict escalation are all interacting in a complex interstate bargaining framework? This article applies a series of competing theoretical explanations for nuclear proliferation and assesses the implications they offer for policy prescriptions. Stressing neo-realist insights, it is s...

Measuring Progress in Conflict Environments (MPICE) - A Metrics Framework for Assessing Conflict Transformation and Stabilization. Version 1.0

Abstract: : There has been a long standing need for "Measures of Effectiveness," as they are often called in the private sector, focused on diplomatic, military and development efforts in places prone to conflict. Traditionally, U.S. Government agencies have tended to measure outputs, such as the number of schools built, miles of roads paved, or numbers of insurgents killed. Outputs, however, measure what we do and not what we achieve. Outcomes, or "effects" as they are known in the military's glossaries, indicate the success or failure of project or mission efforts, since they seek to measure the attainment of conditions that engender stability and self-sustaining peace. The US government (particularly Department of Defense, US Institute of Peace, US Agency for International Development (USAID) and Department of State) has been actively working with a broad array of partners (multinational, NGOs and academia) to develop new capabilities for stability operations. The Measuring Progress in Conflict Environments (MPICE 'pronounced' M-Peace ) project has developed an overarching framework of indicators that measure outcomes over time and across five sectors (Governance, Economics, Security, Rule of Law and Social Well-Being). The MPICE Framework is structured around determining conflict drivers and state/society institutional capacity, as conceptualized by USIP (Quest for Viable Peace), the Fund for Peace, and others. The premise states that if conflict stabilization and societal reconstruction is a process continuum spread between violent conflict and sustainable security at opposite ends, viable peace should be considered the middle or "tipping point" where external intervention forces can begin to hand over driving efforts to local forces and capacities. The MPICE Framework is intended to provide assessment teams with a capability to generate substantial insight into conflict environments and gauge progress with respect to this continuum.

Resonance within the Client-to-Client System: Criticality, Cascades, and Tipping Points

Abstract: Introduction Within an informing system, resonance refers to the ability of a communication to make its way from sender to client once it has already met the standards of quality (e.g., rigor) and usefulness (e.g., relevance). When the term was introduced (Gill & Bhattacherjee, 2007), it was further proposed that resonance had two distinct aspects. The first was the ability of the message to inform a single client. The second was the ability of the message to produce subsequent client-to-client informing activities. Because the theory behind achieving single client resonance is addressed elsewhere (Gill, 2008), the present paper will focus strictly on achieving resonance between clients within the client-to-client component of an informing system. This can be a particularly important process within systems that involve the transfer of complex information. The diffusion of innovation literature (e.g., Rogers, 2003) finds, for example, that client-to-client processes dominate all but the earliest stages of knowledge transfer. Moreover, several different models, mathematical and empirical in origin, have been proposed for a variety of information tasks, but relatively few have been employed within the informing sciences. Thus, the overriding objective of the present paper is to introduce some of these models and consider their respective domains of applicability. We begin by assuming that a message--of acceptable rigor and relevance--has been transmitted by a sender to a very small number of clients within a client community who have subsequently absorbed the message into their own mental models. Our interest is then to understand what subsequently happens to that message within that client community. In the present paper, we consider three models that make fundamentally different assumptions about the nature and motivation for communications: 1. Criticality models: This model is based on the concept of a critical system, most commonly used in the context of nuclear engineering. The simplest of the three models, it could be described as client-sender motivated communications, since it is applicable only when one client who possesses the information is strongly motivated to inform other clients about it. 2. Information Cascade models: Introduced originally in economic theory, this model is normally presented in terms of a client's making a choice between two options for which information about prior client adoptions is available. Although often applied to products (e.g., VCR formats, movies), it can also been applied to pure informing situations, such as the enrollment decision made between alternative classes or the choice of a research topic. It can be characterized as client-recipient motivated informing, since it is the potential recipient who actively decides which option to pursue. 3. Tipping Point models: Building upon assumptions presented in Gladwell's (2000) widely read book The Tipping Point, this model is typical of general diffusion models (e.g., Rogers, 2003) that examine how innovations--including ideas--migrate through communities. It could be characterized as a social-task model, since informing is motivated by both task performance-related criteria and by social criteria. As each of the three models is presented, relevant literature is reviewed. For each model, key parameters that impact informing are identified and a simulation based upon the basic concepts of the particular model is developed. Interesting areas of behavior highlighted by the simulation are then presented and discussed. Finally, areas where each simulation could benefit from refinement are noted. At the end of the paper, some general conclusions regarding the application of the models are presented. Central to these conclusions is the assertion that the client-to-client informing phenomenon is very important. …