Global warming estimates,media expectations,and the asymmetry of scientific challenge

Mass media in the U.S. continue to suggest that scientific consensus estimates of global climate disruption, such as those from the Intergovernmental Panel on Climate Change (IPCC), are “exaggerated” and overly pessimistic. By contrast, work on the Asymmetry of Scientific Challenge (ASC) suggests that such consensus assessments are likely to understate climate disruptions. This paper offers an initial test of the competing expectations, making use of the tendency for science to be self-correcting, over time. Rather than relying in any way on the IPCC process, the paper draws evidence about emerging science from four newspapers that have been found in past work to be biased against reporting IPCC findings, consistently reporting instead that scientific findings are “in dispute.” The analysis considers two time periods — one during the time when the papers were found to be overstating challenges to then-prevailing scientific consensus, and the other focusing on 2008, after the IPCC and former Vice-President Gore shared the Nobel Prize for their work on climate disruption, and before opinion polls showed the U.S. public to be growing more skeptical toward climate science once again. During both periods, new scientific findings were more than twenty times as likely to support the ASC perspective than the usual framing of the issue in the U.S. mass media. The findings indicate that supposed challenges to the scientific consensus on global warming need to be subjected to greater scrutiny, as well as showing that, if reporters wish to discuss “both sides” of the climate issue, the scientifically legitimate “other side” is that, if anything, global climate disruption may prove to be significantly worse than has been suggested in scientific consensus estimates to date.     

People as sensors: Mass media and local temperature influence climate change discussion on Twitter

This study examined whether people living in the US connect their sensory experiences with local temperature to climate change and whether mass media influences the process. We used the volume of Twitter messages containing words “climate change” and “global warming” as the indicator of attention that public pays to the issue. Specifically, the goals were: (1) to investigate whether people immediately notice substantial local weather anomalies such as deviations from long-term mean temperatures and connect them to climate change by contributing to climate change discourse on Twitter and (2) to examine the role of mass media in this process. Over 2 million tweets were collected for a two-year period (2012–2013) and were assigned to 157 urban areas in the continental US. The rate of tweeting on climate change was regressed on the time variables, number of climate change publications in the mass media, and a number of temperature variables. The analysis was conducted at the two levels of aggregation – national and local. The high significance of the mass media and temperature variables in the majority of regression models suggests that both the weather and mass media coverage control public interest to the topic. However, no convincing evidence was found that the media acts as a mediator in the relationship between local weather and climate change discourse. Overall, the findings confirmed that the public recognize extreme temperature anomalies and connect these anomalies to climate change.     

Declining public concern about climate change: Can we blame the great recession?

Social surveys suggest that the American public's concern about climate change has declined dramatically since 2008. This has led to a search for explanations for this decline, and great deal of speculation that there has been a fundamental shift in public trust in climate science. We evaluate over thirty years of public opinion data about global warming and the environment, and suggest that the decline in belief about climate change is most likely driven by the economic insecurity caused by the Great Recession. Evidence from European nations further supports an economic explanation for changing public opinion. The pattern is consistent with more than forty years of public opinion about environmental policy. Popular alternative explanations for declining support – partisan politicization, biased media coverage, fluctuations in short-term weather conditions – are unable to explain the suddenness and timing of opinion trends. The implication of these findings is that the “crisis of confidence” in climate change will likely rebound after labor market conditions improve, but not until then.     

Dynamic normals of surface air temperature

Cited are the latest data on the contemporary climate changes in surface air temperature (to the year 2011 inclusive). Substantiated is the necessity of extending the concept on the normals and anomalies of surface air temperature under conditions of the changing climate. Formulated is a concept of “dynamic normals” and “dynamic anomalies” of surface air temperature taking account of current trends of climate change and interseasonal variations. It is proposed to adopt this concept both for the problems of forthcoming climate change assessments and for the long-range forecasting out of the “limit of predictability.” An adaptive regression method is proposed to compute such dynamic normals as a function of the indicator of global climate changes. Presented are the skill scores of dynamic normals as of “intermediate” forecasts (an analogue of the climate forecast under a changing climate).     

Text-mining the signals of climate change doubt

Climate scientists overwhelmingly agree that the Earth is getting warmer and that the rise in average global temperature is predominantly due to human activity. Yet a significant proportion of the American public, as well as a considerable number of legislators in the U.S. Congress, continue to reject the “consensus view.” While the source of the disagreement is varied, one prominent explanation centres on the activities of a coordinated and well-funded countermovement of climate sceptics. This study contributes to the literature on organized climate scepticism by providing the first systematic overview of conservative think tank sceptical discourse in nearly 15 years. Specifically, we (1) compile the largest corpus of contrarian literature to date, collecting over 16,000 documents from 19 organizations over the period 1998–2013; (2) introduce a methodology to measure key themes in the corpus which scales to the substantial increase in content generated by conservative think tanks over the past decade; and (3) leverage this new methodology to shed light on the relative prevalence of science- and policy-related discussion among conservative think tanks. We find little support for the claim that “the era of science denial is over”—instead, discussion of climate science has generally increased over the sample period.     

Public microblogging on climate change: One year of Twitter worldwide

Public perceptions of climate change are traditionally measured through surveys. The exploding popularity of social networks, however, presents a new opportunity to research the spatiotemporal pattern of public discourse in relation to natural and/or socio-economic events. Among the social networks, Twitter is one of the largest microblogging services. The architecture of Twitter makes the question “what's happening?” the cornerstone of information exchange. This inspired the notion of using Twitter users as distributed sensors, which has been successfully employed in both the natural and social sciences. In 2012 and 2013, we collected 1.8 million tweets on “climate change” and “global warming” in five major languages (English, German, Russian, Portuguese, and Spanish). We discuss the geography of tweeting, weekly and daily patterns, major news events that affected tweeting on climate change, changes in the central topics of discussion over time, the most authoritative traditional media, blogging, and the most authoritative organizational sources of information on climate change referenced by Twitter users in different countries. We anticipate that social network mining will become a major source of data in the public discourse on climate change.     

Does socioeconomic status moderate the political divide on climate change? The roles of education,income, and individualism

Previous research documents that U.S. conservatives, and conservative white males in particular, tend to dismiss the threat of climate change more than others in the U.S. public. Other research indicates that higher education and income can each exacerbate the dismissive tendencies of the political Right. Bridging these lines of research, the present study examines the extent to which higher education and/or income moderate the ideological divide and the “conservative white male effect” on several climate change opinions, and whether these effects are mediated by an individualistic worldview (e.g., valuing individual liberty and limited government). Using nationally representative survey data of U.S. adults from 2008 to 2017 (N = 20,024), we find that across all beliefs, risk perceptions, and policy preferences examined, the ideological divide strengthens with both higher education and higher income. However, educational attainment plays a stronger role than income in polarizing the views of conservative white males. Further analyses support the hypothesis that differences in individualism partially explain the increased political polarization among more educated and higher-income adults, as well as greater dismissiveness among conservative white males relative to other demographic groups. These results highlight key moderators of opinion polarization, as well as ideological differences among conservatives, that are often overlooked in public discourse about climate change. Implications for climate change education and communication across demographic groups are considered.     

Precipitation anomalies,economic production,and the role of “first-nature” and “second-nature” geographies: A disaggregated analysis in high-income countries

Linkages between hydroclimate variability and economic development are often theorized to be present only in developing economies. Using spatially small-scaled data from multiple decades for European regions, we examine the relationship between precipitation anomalies and economic performance in highly developed economic systems. We conduct a disaggregated empirical analysis to mitigate the bias potentially arising from spatial aggregation because precipitation realizations tend to vary drastically within larger sized economic units. We modify original precipitation indices to capture the dynamic expectation formation of economic agents about climate conditions to measure deviations from these anticipated environmental states. Using panel model regressions in a quasi-experimental research design, we analyse whether deviations from average growth rates of aggregated economic output are potentially non-linearly related to the magnitude of precipitation deviations from the anticipated climate norm within regions, after accounting for any shocks common to all regions. We find that precipitation deviations that exceed critical thresholds (intermediate anomalies) for both unusually dry and unusually wet years reduce regional growth rates. The adverse impacts are more pronounced for overly dry periods. Importantly, the relationship between economic growth and precipitation anomalies is not generalizable across all regions. Natural geographical circumstances such as prevailing climatic conditions (“first-nature” geographies) and human-made socio-economic factors such as sector structure and income level (“second-nature” geographies) moderate the anomaly response. The empirical findings substantiate the necessity to incorporate precipitation variability into the assessment of economic costs of climate change; not only in developing countries or agricultural societies but also in highly developed economic systems. Moreover, the empirical results have important implications for policy makers as uneven effect sizes at the subnational level suggest that policy measures should be targeted in space and coordinated between national and regional levels of government.     

基于动态重现期的极端高温气候评估方法研究

利用全国754站逐日最高气温观测序列,在论证极端温度概率分布与非平稳性关系的基础上,构建和比较了多种非平稳广义极值模型,定义了极端高温的动态重现期和重现水平,提出了一种极端高温事件的新型评估思想和方法,并将其应用于极端气候变化研究。通过该方法可以更好地解释极端事件的真实极端性,有效地增强极端事件之间的可比性,从而保留更多历史极端气候事件的信息。动态重现期的变换运用可对当前极端事件发生的真实状态和趋势提出更准确评估。该方法的提出可有效澄清学术领域和公共舆论对于多年一遇极端事件的理解上长期混淆重现期的绝对值和概率性这一分歧和谬误。     

“Natural cycles” in lay understandings of climate change

This article analyses lay understandings of climate change elicited through a longitudinal population-based survey of climate change, place and community among 1162 residents in the Hunter Valley, Southeast Australia. We explore how older residents in contrasting rural and coastal geographic areas perceive climate change information in terms of culturally relevant meanings and values, lived experiences and emotional responses to seasonal cycles, temperature fluctuations and altered landscapes. Thematic analysis of comments given by 467 interviewees to an open-ended question identified a significant subset for whom the concepts of “nature” and “science” express competing views about changing climatic conditions. For them, the idea of “natural cycles” is a significant cultural construct that links nature and humans through time in a way that structures stable and resilient understandings of environmental change, drawing on established cosmological frameworks for contemplating the future in relation to the past. In contrast to other studies that postulate scepticism and denial as individuals’ fear management strategies in the face of climate change threat, we found that the natural cycles view is founded on a reassuring deeper conviction about how nature works, and is linked to other pro-environmental values not commonly found in sceptical groups. It is a paradox of natural cycles thinking that it rejects the anthropocentrism that is at the heart of science-based environmentalism. By contrast, it places humans as deeply integrated with nature, rather than operating outside it and attempting with uncertain science to control something that is ultimately uncontrollable.     

Lost in translation? United States television news coverage of anthropogenic climate change, 1995–2004

Eminent climate scientists have come to consensus that human influences are significant contributors to modern global climate change. This study examines coverage of anthropogenic climate change in United States (U.S.) network television news – ABC World News Tonight, CBS Evening News and NBC Nightly News – and focuses on the application of the journalistic norm of ‘balance’ in coverage from 1995 through 2004. This study also examines CNN WorldView, CNN Wolf Blitzer Reports and CNN NewsNight as illustrations of cable news coverage. Through quantitative content analysis, results show that 70% of U.S. television news segments have provided ‘balanced’ coverage regarding anthropogenic contributions to climate change vis-à-vis natural radiative forcing, and there has been a significant difference between this television coverage and scientific consensus regarding anthropogenic climate change from 1996 through 2004. Thus, by way of the institutionalized journalistic norm of balanced reporting, United States television news coverage has perpetrated an informational bias by significantly diverging from the consensus view in climate science that humans contribute to climate change. Troubles in translating this consensus in climate science have led to the appearance of amplified uncertainty and debate, also then permeating public and policy discourse.     

基于哥本哈根学派的中国气候安全化比较分析

采用哥本哈根学派提出的安全化方法,对中美气候安全化水平进行对比,结果表明：安全是一种主体间现象,通过中美气候安全化水平的对比,可以清楚地识别出中国处于由政治权威、科学权威作为安全化主体的高强度“安全化”过程中,而美国正处于由政治权威引导的“反安全化”过程。“主体间性”是安全化主体之间对存在性威胁的认同程度,中国气候安全化的主体间性与气候安全化进程不协调,表现为中国政治高层的气候安全化水平较高,而公众的安全化水平相对较低。气候安全存在性威胁表达是制约中国公众气候安全化水平的重要因素,表现为安全化视角和媒介单一。建议通过引入全球视角和图形化等方式增强存在性威胁表达效果,以提升中国气候安全化水平。     

Atlantic Multidecadal Oscillation and Northern Hemisphere’s climate variability

Proxy and instrumental records reflect a quasi-cyclic 50–80-year climate signal across the Northern Hemisphere, with particular presence in the North Atlantic. Modeling studies rationalize this variability in terms of intrinsic dynamics of the Atlantic Meridional Overturning Circulation influencing distribution of sea-surface-temperature anomalies in the Atlantic Ocean; hence the name Atlantic Multidecadal Oscillation (AMO). By analyzing a lagged covariance structure of a network of climate indices, this study details the AMO-signal propagation throughout the Northern Hemisphere via a sequence of atmospheric and lagged oceanic teleconnections, which the authors term the “stadium wave”. Initial changes in the North Atlantic temperature anomaly associated with AMO culminate in an oppositely signed hemispheric signal about 30?years later. Furthermore, shorter-term, interannual-to-interdecadal climate variability alters character according to polarity of the stadium-wave-induced prevailing hemispheric climate regime. Ongoing research suggests mutual interaction between shorter-term variability and the stadium wave, with indication of ensuing modifications of multidecadal variability within the Atlantic sector. Results presented here support the hypothesis that AMO plays a significant role in hemispheric and, by inference, global climate variability, with implications for climate-change attribution and prediction.     

Understanding U.S. public support for domestic climate change policies

In the U.S., public support for federal, state and local efforts to reduce greenhouse gases (GHGs) continues to be a crucial element of the political viability of these proposals. We present a detailed analysis of the reasons given by the general public of Michigan and Virginia for supporting or rejecting a number of policies that could be implemented to meet GHG reductions. The data allow us to analyze the relationships between reasons provided by respondents, social psychological and demographic characteristics, and policy support. This analysis can provide policymakers pragmatic guidance in (1) developing tactics to engage the public that build on current concerns about climate change policies and (2) crafting and communicating policies that garner support from various segments of the public. This analysis also raises theoretical questions regarding the relationship between public discourse on environmental issues and the formation of public policy support. We suggest that future efforts to understand the U.S. dynamics of public support for climate change policies could benefit from understanding the public discursive and the reasoning processes that underlie public opinion formation.     

Arguing for climate policy through the linguistic construction of narratives and voices: the case of the South-African green paper “National Climate Change Response”

The purpose of the present paper is to examine a selection of macro- and micro-linguistic features (at text and sentence/word level respectively) of the South-African Green Paper “National Climate Change Response” from 2010. Our overarching assumption is that the Green Paper needs to handle competing interests, beliefs and voices in a narrative structure favouring specific courses of action. How does the government portray the complex natural and societal phenomenon of climate change, and how does it take into account the many and often competing national and international views and interests which come into play? Our hypothesis is that the Green Paper constructs a narrative and that it relates to a number of voices other than that of the authors, through linguistic markers of polyphony, such as negation, sentence connectives, adverbs and reported speech. Thus we propose a narrative and polyphonic analysis of the Green Paper, at the level of the text as a whole (macro-level) but also with attention to linguistic constructions of polyphony or “multi-voicedness” (micro-level). We find that the narrative-polyphonic properties of the Green Paper contribute to a strategy for building consensus on climate change policy. The South African government assumes the role of main hero in its own climate change “story”, and there are subtle forms of interaction with different and typically non-identified voices, such as concessive constructions and presuppositions. These results support our overarching interpretation of the whole document as striving to impose a South African consensus on the issue of climate change.     

Climate skepticism decreases when the planet gets hotter and conservative support wanes

Identifying historical patterns of fluctuation in climate change skepticism guides researchers, policy makers, and science communicators in efforts to catalyze change in the future. We analyzed data from 25 nationally representative polls collected in Australia from 2009 to 2019 (N = 20,655). Although it remains concerningly high, climate skepticism trended down in that 10-year period, particularly among conservatives. Multilevel analyses identified two variables that stood out as being relevant in explaining that trajectory. First, climate change skepticism was positively associated with support for conservative political parties in national polls. Second, climate change skepticism was negatively associated with the annual global temperatures the previous year. There was little evidence that climate change beliefs were associated with economic variables or with seasonal variations in temperature. Furthermore, there was only weak evidence that climate change beliefs were associated with national temperatures. This suggests that global temperatures in the previous year are impactful because of their informational value (as a communication heuristic for the urgency and immediacy of climate change) more so than for their experiential value (in the sense of people actually experiencing warmer weather). Importantly, the effect of previous global temperature was particularly pronounced among those with the strongest levels of skepticism: political conservatives. This suggests that rising global annual temperatures have the power to update beliefs among those most in need of converting to the climate cause.     

Past millennial solar forcing magnitude

A set of global climate model simulations for the last thousand years developed by the Max Planck Institute is compared with paleoclimate proxy data and instrumental data, focusing on surface temperatures for land areas between 30° and 75°N. The proxy data are obtained from six previously published Northern Hemispheric-scale temperature reconstructions, here re-calibrated for consistency, which are compared with the simulations utilizing a newly developed statistical framework for ranking several competing simulations by means of their statistical distance against past climate variations. The climate model simulations are driven by either “low” or “high” solar forcing amplitudes (0.1 and 0.25 % smaller total solar irradiance in the Maunder Minimum period compared to the present) in addition to several other known climate forcings of importance. Our results indicate that the high solar forcing amplitude results in a poorer match with the hemispheric-scale temperature reconstructions and lends stronger statistical support for the low-amplitude solar forcing. However, results are likely conditional upon the sensitivity of the climate model used and strongly dependent on the choice of temperature reconstruction, hence a greater consensus is needed regarding the reconstruction of past temperatures as this currently provides a great source of uncertainty.     

The modulated annual cycle: an alternative reference frame for climate anomalies

In climate science, an anomaly is the deviation of a quantity from its annual cycle. There are many ways to define annual cycle. Traditionally, this annual cycle is taken to be an exact repeat of itself year after year. This stationary annual cycle may not reflect well the intrinsic nonlinearity of the climate system, especially under external forcing. In this paper, we re-examine the reference frame for anomalies by re-examining the annual cycle. We propose an alternative reference frame for climate anomalies, the modulated annual cycle (MAC) that allows the annual cycle to change from year to year, for defining anomalies. In order for this alternative reference frame to be useful, we need to be able to define the instantaneous annual cycle: we therefore also introduce a new method to extract the MAC from climatic data. In the presence of a MAC, modulated in both amplitude and frequency, we can then define an alternative version of an anomaly, this time with respect to the instantaneous MAC rather than a permanent and unchanging AC. Based on this alternative definition of anomalies, we re-examine some familiar physical processes: in particular SST re-emergence and ENSO phase locking to the annual cycle. We find that the re-emergence mechanism may be alternatively interpreted as an explanation of the change of the annual cycle instead of an explanation of the interannual to interdecadal persistence of SST anomalies. We also find that the ENSO phase locking can largely be attributed to the residual annual cycle (the difference of the MAC and the corresponding traditional annual cycle) contained in the traditional anomaly, and, therefore, can be alternatively interpreted as a part of the annual cycle phase locked to the annual cycle itself. In addition to the examples of reinterpretation of physics of well known climate phenomena, we also present an example of the implications of using a MAC against which to define anomalies. We show that using MAC as a reference framework for anomaly can bypass the difficulty brought by concepts such as “decadal variability of summer (or winter) climate” for understanding the low-frequency variability of the climate system. The concept of an amplitude and frequency modulated annual cycle, a method to extract it, and its implications for the interpretation of physical processes, all may contribute potentially to a more consistent and fruitful way of examining past and future climate variability and change.     

On long range dependence in global surface temperature series

Long Range Dependence (LRD) scaling behavior has been argued to characterize long-term surface temperature time series. LRD is typically measured by the so-called “Hurst” coefficient, “H”. Using synthetic temperature time series generated by a simple climate model with known physics, I demonstrate that the values of H obtained for observational temperature time series can be understood in terms of the linear response to past estimated natural and anthropogenic external radiative forcing combined with the effects of random white noise weather forcing. The precise value of H is seen to depend on the particular noise realization. The overall distribution obtained over an ensemble of noise realizations is seen to be a function of the relative amplitude of external forcing and internal stochastic variability and additionally in climate “proxy” records, the amount of non-climatic noise present. There is no obvious reason to appeal to more exotic physics for an explanation of the apparent scaling behavior in observed temperature data.