AGW Observer

Observations of anthropogenic global warming

Archive for October, 2010

AGW Observer goes social!

Posted by Ari Jokimäki on October 5, 2010

You can now find AGW Observer also from





Posted in General | 2 Comments »

Papers on media and climate change

Posted by Ari Jokimäki on October 4, 2010

This is a list of papers on the media and climate change. The list is not complete, and will most likely be updated in the future in order to make it more thorough and more representative.

UPDATE (February 2, 2011): “Additional papers” section added including lot of papers. Thanks to Alon for providing a huge list of papers, see the comment section.

Self-censorship and science: a geographical review of media coverage of climate tipping points – Antilla (2010) “Public perception of global climate change is strongly influenced by media constructions of scientific knowledge. This paper explores recent scientific findings and the press coverage thereof and is based on a content analysis of two years of global reporting on climate related positive feedback mechanisms (climate system responses to global warming which lead to further warming). Results indicate that non-US news organizations, especially in the UK, are at the forefront of the discourse on climate feedback loops. Poor US press coverage on such climate thresholds might be understood not only as self-censorship, but as a “false negative” error.” Liisa Antilla, Public Understanding of Science March 2010 vol. 19 no. 2 240-256, doi: 10.1177/0963662508094099. [Full text]

Media, Politics and Climate Change: Towards a New Research Agenda – Anderson (2009) “Climate change is one of the most pressing issues of our time, and the media have been demonstrated to play a key role in shaping public perceptions and policy agendas. Journalists are faced with multiple challenges in covering this complex field. This article provides an overview of existing research on the media framing of climate change, highlighting major research themes and assessing future potential research developments. It argues that analysis of the reporting of climate science must be placed in the wider context of the growing concentration and globalization of news media ownership, and an increasingly ‘promotional culture’, highlighted by the rapid rise of the public relations industry in recent years and claims-makers who employ increasingly sophisticated media strategies. Future research will need to examine in-depth the targeting of media by a range of actors, as well as unravel complex information flows across countries as media increasingly converge.” [Full text]

Global warming—global responsibility? Media frames of collective action and scientific certainty – Olausson (2009) “The increasing interconnectedness of the world that characterizes the process of globalization compels us to interlink local, national, and transnational phenomena, such as environmental risks, in both journalistic and academic discourse. Among environmental risks of global scope climate change is probably the one receiving the most attention at present, not least in the media. Globalization notwithstanding, national media are still dominated by a national logic in the presentation of news, and tensions arise between this media logic and the transnational character of environmental risks that call for a collective responsibility transcending the borders of the nation-states. This article presents results from studies of the construction of global climate change in three Swedish newspapers. It discusses the media’s attribution of responsibility for collective action along an axis ranging from local to national to transnational, and highlights the media’s reluctance to display any kind of scientific uncertainty that would undermine the demand for collective action. The results underline the media’s responsiveness to the political setting in which they operate and the growing relevance of the transnational political realm of Europe for the construction of news frames on global climate change in European national media.” [Full text]

Ideological cultures and media discourses on scientific knowledge: re-reading news on climate change – Carvalho (2007) “Focusing on the representation of climate change in the British “quality press,” this article argues that the discursive (re)construction of scientific claims in the media is strongly entangled with ideological standpoints. Understood here as a set of ideas and values that legitimate a program of action vis-à-vis a given social and political order, ideology works as a powerful selection device in deciding what is scientific news, i.e. what the relevant “facts” are, and who are the authorized “agents of definition” of science matters. The representation of scientific knowledge has important implications for evaluating political programs and assessing the responsibility of both governments and the public in addressing climate change.” Anabela Carvalho, Public Understanding of Science April 2007 vol. 16 no. 2 223-243, doi: 10.1177/0963662506066775. [Full text]

Flogging a dead norm? Newspaper coverage of anthropogenic climate change in the United States and United Kingdom from 2003 to 2006 – Boykoff (2007) “The journalistic norm of ‘balanced’ reporting (giving roughly equal coverage to both sides in any significant dispute) is recognised as both useful and problematic in communicating emerging scientific consensus on human attribution for global climate change. Analysis of the practice of this norm in United States (US) and United Kingdom (UK) newspaper coverage of climate science between 2003 and 2006 shows a significant divergence from scientific consensus in the US in 2003–4, followed by a decline in 2005–6, but no major divergence in UK reporting. These findings inform ongoing considerations about the spatially-differentiated media terms and conditions through which current and future climate policy is negotiated and implemented.” [Full text]

From convergence to contention: United States mass media representations of anthropogenic climate change science – Boykoff (2007) “This article focuses on connected factors that contribute to United States (US) media reporting on anthropogenic climate change science. It analyses US newspapers and television news from 1995 to 2006 as well as semi-structured interviews with climate scientists and environmental journalists. Through analyses of power and scale, the paper brings together issues of framing in journalism to questions of certainty/uncertainty in climate science. The paper examines how and why US media have represented conflict and contentions, despite an emergent consensus view regarding anthropogenic climate science.” Maxwell T Boykoff, Transactions of the Institute of British Geographers, Volume 32, Issue 4, pages 477–489, October 2007, DOI: 10.1111/j.1475-5661.2007.00270.x. [Full text]

A Tale of Two Fears: Exploring Media Depictions of Nuclear Power and Global Warming – Palfreman (2006) “Advanced technologies like nuclear power and looming environmental threats such as global climate change present major policy challenge for modern cultures. Public policy about such crucial and complex issues depends on public attitudes, which, in turn, tend to be strongly affected by mass media coverage. How “well” has the mass media portrayed these two evolving risk stories? Employing perspectives from both journalism and social science, this article will first review the history of mass media coverage of each topic, then analyze their differences.” Jon Palfreman, Review of Policy Research, Volume 23, Issue 1, pages 23–43, January 2006, DOI: 10.1111/j.1541-1338.2006.00184.x.

Climate of scepticism: US newspaper coverage of the science of climate change – Antilla (2005) “This two-part study integrates a quantitative review of one year of US newspaper coverage of climate science with a qualitative, comparative analysis of media-created themes and frames using a social constructivist approach. In addition to an examination of newspaper articles, this paper includes a reflexive comparison with attendant wire stories and scientific texts. Special attention is given to articles constructed with and framed by rhetoric emphasising uncertainty, controversy, and climate scepticism.” Liisa Antilla, Global Environmental Change Part A, Volume 15, Issue 4, December 2005, Pages 338-352, doi:10.1016/j.gloenvcha.2005.08.003. [Full text]

Cultural Circuits of Climate Change in U.K. Broadsheet Newspapers, 1985-2003 – Carvalho & Burgess (2005) “This article argues for a cultural perspective to be brought to bear on studies of climate change risk perception. Developing the “circuit of culture” model, the article maintains that the producers and consumers of media texts are jointly engaged in dynamic, meaning-making activities that are context-specific and that change over time. A critical discourse analysis of climate change based on a database of newspaper reports from three U.K. broadsheet papers over the period 1985-2003 is presented. This empirical study identifies three distinct circuits of climate change—1985-1990, 1991-1996, 1997-2003—which are characterized by different framings of risks associated with climate change. The article concludes that there is evidence of social learning as actors build on their experiences in relation to climate change science and policy making. Two important factors in shaping the U.K.’s broadsheet newspapers’ discourse on “dangerous” climate change emerge as the agency of top political figures and the dominant ideological standpoints in different newspapers.” Carvalho, Anabela; Burgess, Jacquelin, Risk Analysis, Volume 25, Number 6, December 2005 , pp. 1457-1469(13), DOI: 10.1111/j.1539-6924.2005.00692.x. [Full text]

Balance as bias: global warming and the US prestige press – Boykoff & Boykoff (2004) “This paper demonstrates that US prestige-press coverage of global warming from 1988 to 2002 has contributed to a significant divergence of popular discourse from scientific discourse. This failed discursive translation results from an accumulation of tactical media responses and practices guided by widely accepted journalistic norms. Through content analysis of US prestige press—meaning the New York Times, the Washington Post, the Los Angeles Times, and the Wall Street Journal—this paper focuses on the norm of balanced reporting, and shows that the prestige press’s adherence to balance actually leads to biased coverage of both anthropogenic contributions to global warming and resultant action.” Maxwell T. Boykoff and Jules M. Boykoff, Global Environmental Change Part A, Volume 14, Issue 2, July 2004, Pages 125-136, doi:10.1016/j.gloenvcha.2003.10.001. [Full text]

Testing Public (Un)Certainty of Science Media Representations of Global Warming – Corbett & Dufree (2004) “This exploratory study examines whether readers’assessments of the certainty of scientific findings depend on characteristics of news stories. An experimental design tested whether adding controversy and/or context to a news story about global warming influenced readers’ perceptions of its certainty. Respondents (N = 209) were randomly assigned to read one treatment and answer a questionnaire. Overall, there was a significant difference in readers’assessment of the certainty of global warming across treatments (F = 12.59, p = .00). The context treatment produced the highest level of certainty about global warming and differed significantly from the control treatment (with neither context nor controversy) and from the controversy treatment. Control and controversy treatments resulted in the lowest levels of certainty. There was an interaction effect between treatment and environmental ideology upon certainty (F = 1.64, p = .03) and a correlation between environmental ideology and prior certainty about global warming (r = .35, p = .01), suggesting that those with proenvironmental ideology were less swayed by the treatments.” Julia B. Corbett and Jessica L. Durfee, Science Communication December 2004 vol. 26 no. 2 129-151, doi: 10.1177/1075547004270234. [Full text]

Media’s social construction of environmental issues: focus on global warming – a comparative study – Dispensa & Brulle (2003) “Global warming has been a well recognized environmental issue in the United States for the past ten years, even though scientists had identified it as a potential problem years before in 1896. We find debate about the issue in the United States media coverage while controversy among the majority of scientists is rare. The role that media plays in constructing the norms and ideas in society is researched to understand how they socially construct global warming and other environmental issues. To identify if the U.S. Media presents a biased view of global warming, the following are discussed (1) the theoretical perspective of media and the environment; (2) scientific overview and history of global warming; (3) media coverage of global warming, and (4) research findings from the content analysis of three countries’ newspaper articles and two international scientific journals produced in 2000 with comparison of these countries economies, industries, and environments. In conclusion, our research demonstrates that the U.S. with differing industries, predominantly dominated by the fossil fuel industry, in comparison to New Zealand and Finland has a significant impact on the media coverage of global warming. The U.S’s media states that global warming is controversial and theoretical, yet the other two countries portray the story that is commonly found in the international scientific journals. Therefore, media, acting as one driving force, is providing citizens with piecemeal information that is necessary to assess the social, environmental and political conditions of the country and world.” Jaclyn Marisa Dispensa, Robert J. Brulle, 2003, International Journal of Sociology and Social Policy, Vol. 23 Iss: 10, pp.74 – 105. [Full text]

How Science Contributes to Environmental Reporting in British Newspapers: A Case Study of the Reporting of Global Warming and Climate Change – Taylor & Nathan (2002) “This article examines the role of science in environmental reporting in a number of British newspapers. The findings indicated that in reporting about global warming and climate change, the views of scientists were used to give legitimacy to the content of articles. However, in both the tabloids and broadsheets, there was little evidence provided, in the form of data, to substantiate the claims being made. Furthermore, uncertainties about global warming were not explored effectively. Newspaper reports tended to focus on the potential consequences of global warming, but made little attempt to address the suspected causes that would inevitably involve criticism of highly consumptive lifestyles in the west.” Neil Taylor and Subhashni Nathan, The Environmentalist, Volume 22, Number 4, 325-331, DOI: 10.1023/A:1020762813548.

Heat and hot air: influence of local temperature on journalists’ coverage of global warming – Shanahan & Good (2000) “This study examines relationships between local temperature in two cities (New York and Washington, D.C.) and coverage of global climate change in their local newspapers (the Times and the Post). The results show that there are some relationships between local temperature and frequency of attention to climate issues, such that journalists are more likely to discuss climate during unusually warm periods. However, support for the hypotheses was only partial; the Post did not show confirming relationships. The discussion focuses on implications for public understanding of climate change.” James Shanahan, Jennifer Good, Public Understanding of Science July 2000 vol. 9 no. 3 285-295, doi: 10.1088/0963-6625/9/3/305.

Telling Stories About Global Climate Change – McComas & Shanahan (1999) “A theory of cyclical patterns in media coverage of environmental issues must account for more than intrinsic qualities of the issues themselves: Narrative factors must be considered. A content analysis of The New York Times and The Washington Post stories from 1980 to 1995 shows how media construct narratives about global warming and how these narratives may influence attention cycles. Empirically, the frequency of newspaper coverage shows cyclical attention to global warming. The content analysis further reveals that implied danger and consequences of global warming gain more prominence on the upswing of newspaper attention, whereas controversy among scientists receives greater attention in the maintenance phase. The economics of dealing with global warming also receive greater attention during the maintenance and downside of the attention cycle. The discussion offers a narrative explanation and suggests the outcome of the “master story” of global climate change may discourage future attention to global warming.” Katherine McComas, James Shanahan, Communication Research February 1999 vol. 26 no. 1 30-57, doi: 10.1177/009365099026001003.

Global Environmental Change in the News: 1987-90 vs 1992-6 – Mazur (1998) “Hazards to the global environment, including climate change, ozone depletion, rainforest destruction, & species extinction, became important problems on the US agenda of risks after extensive media coverage, 1987-1990, & were subsequently taken up by other nations, at least until news coverage fell after 199O. Shown here is why these particular hazards, which had all been recognized by experts for years, suddenly became important news stories, & why they failed to attract much media attention during the period 1992-1996, a time when global warming & other problems intensified, & the White House was occupied by an administration ostensibly sympathetic to environmental concerns.” Mazur, A., International Sociology. Vol. 13, no. 4, pp. 457-472. 1998.

Additional papers

Anderegg, W. R. L., Prall, J. W., Harold, J., & Schneider, S. H. (2010). Expert credibility in climate change. Proceedings of the National Academy of Sciences, 107(27), 12107 -12109. doi:10.1073/pnas.1003187107. [abstract, full text]

Arlt, D., Hoppe, I., & Wolling, J. (2011). Climate change and media usage: Effects on problem awareness and behavioural intentions. International Communication Gazette, 73(1-2), 45 -63. doi:10.1177/1748048510386741. [abstract]

Bäckstrand, K., & Lövbrand, E. (2011). Planting Trees to Mitigate Climate Change: Contested Discourses of Ecological Modernization, Green Governmentality and Civic Environmentalism. Global Environmental Politics, 6(1), 50-75. doi:10.1162/glep.2006.6.1.50. [abstract]

Beck, U. Climate for Change, or How to Create a Green Modernity? Theory, Culture & Society, 27(2-3), 254 -266. doi:10.1177/0263276409358729. [abstract]

Bell, A. (1994a). Climate of Opinion: Public and Media Discourse on the Global Environment. Discourse & Society, 5(1), 33 -64. doi:10.1177/0957926594005001003. [abstract]

Bell, A. (1994b). Media (mis)communication on the science of climate change. Public Understanding of Science, 3(3), 259 -275. doi:10.1088/0963-6625/3/3/002. [abstract]

Berk, R. A., & Schulman, D. (1995). Public perceptions of global warming. Climatic Change, 29(1), 1-33. doi:10.1007/BF01091637. [abstract]

Billett, S. (2009). Dividing climate change: global warming in the Indian mass media. Climatic Change, 99(1-2), 1-16. doi:10.1007/s10584-009-9605-3. [abstract, full text]

Bokwa, A. (2003). Climatic issues in Polish printed mass media. In J. Pyka, M. Dubicka, A. Szczepankiewicz-Szmyrka, M. Sobkik, & M. Blas (Eds.), Man and Climate in the 20th Century (pp. 619-626). Wroclaw: Wydawnictwo Uniwersytetu Wroclawskiego.

Boykoff, M. (2010). Indian media representations of climate change in a threatened journalistic ecosystem. Climatic Change, 99(1-2), 17-25. doi:10.1007/s10584-010-9807-8. [abstract, full text]

Boykoff, M. T., & Mansfield, M. (2008). ‘Ye Olde Hot Aire’: reporting on human contributions to climate change in the UK tabloid press. Environmental Research Letters, 3(2), 024002. doi:10.1088/1748-9326/3/2/024002. [abstract, full text]

Boykoff, M. T., & Rajan, S. R. (2007). Signals and noise. Mass-media coverage of climate change in the USA and the UK. EMBO Reports, 8(3), 207-211. doi:10.1038/sj.embor.7400924. [abstract, full text]

Boykoff, M. T. (2007). Lost in translation? United States television news coverage of anthropogenic climate change, 1995–2004. Climatic Change, 86(1-2), 1-11. doi:10.1007/s10584-007-9299-3. [abstract]

Boykoff, M. T. (2008a). Media and scientific communication: a case of climate change. Geological Society, London, Special Publications, 305(1), 11 -18. doi:10.1144/SP305.3. [abstract, full text]

Boykoff, M. T. (2008b). The cultural politics of climate change discourse in UK tabloids. Political Geography, 27(5), 549-569. doi:10.1016/j.polgeo.2008.05.002. [abstract, full text]

Boykoff, M. T. (2009). We Speak for the Trees: Media Reporting on the Environment. Annual Review of Environment and Resources, 34(1), 431-457. doi:10.1146/annurev.environ.051308.084254. [abstract, full text]

Boykoff, M. T., & Boykoff, J. M. (2007). Climate change and journalistic norms: A case-study of US mass-media coverage. Geoforum, 38(6), 1190-1204. doi:10.1016/j.geoforum.2007.01.008. [abstract, full text]

Boykoff, M. T., Frame, D., & Randalls, S. (2010). Discursive stability meets climate instability: A critical exploration of the concept of [`]climate stabilization’ in contemporary climate policy. Global Environmental Change, 20(1), 53-64. doi:10.1016/j.gloenvcha.2009.09.003. [abstract, full text]

Boykoff, M. T., & Roberts, J. T. (2007). Media coverage of climate change: Current trends, strengths, weaknesses (Occassional Paper No. 2007/3). Human Development Report Office, United Nations Development Programme. [abstract, full text]

Brossard, D., Shanahan, J., & McComas, K. (2004). Are Issue-Cycles Culturally Constructed? A Comparison of French and American Coverage of Global Climate Change. Mass Communication and Society, 7(3), 359. doi:10.1207/s15327825mcs0703_6. [abstract, full text]

Brown, T., Budd, L., Bell, M., & Rendell, H. The local impact of global climate change: Reporting on landscape transformation and threatened identity in the English regional newspaper press. Public Understanding of Science. doi:10.1177/0963662510361416. [abstract]

Carvalho, A. (2005). Representing the politics of the greenhouse effect: — Discursive strategies in the British media. Critical Discourse Studies, 2(1), 1. doi:10.1080/17405900500052143. [abstract]

Carvalho, A. (2010). Media(ted)discourses and climate change: a focus on political subjectivity and (dis)engagement. Wiley Interdisciplinary Reviews: Climate Change, n/a-n/a. doi:10.1002/wcc.13. [abstract]

Corfee-Morlot, J., Maslin, M., & Burgess, J. (2007). Global warming in the public sphere. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 365(1860), 2741-2776. doi:10.1098/rsta.2007.2084. [abstract, full text]

Curtin, P. A., & Rhodenbaugh, E. (2001). Building the news media agenda on the environment: a comparison of public relations and journalistic sources. Public Relations Review, 27(2), 179-195. doi:10.1016/S0363-8111(01)00079-0. [abstract, full text]

Demeritt, D. (2001). The Construction of Global Warming and the Politics of Science. Annals of the Association of American Geographers, 91(2), 307. doi:10.1111/0004-5608.00245. [abstract, full text]

Dirikx, A., & Gelders, D. (2007). Newspaper communication on global warming: Different approaches in the US and the EU? In A. Carvalho (Ed.), Communicating Climate Change: Discourses, Mediations and Perceptions (pp. 98-109). Braga: Centro de Estudos de Comunicação e Sociedade, Universidade do Minho. [abstract, full text]

Dirikx, A., & Gelders, D. (2010). To frame is to explain: A deductive frame-analysis of Dutch and French climate change coverage during the annual UN Conferences of the Parties. Public Understanding of Science, 19(6), 732 -742, doi:10.1177/0963662509352044. [abstract]

Doulton, H., & Brown, K. (2009). Ten years to prevent catastrophe?: Discourses of climate change and international development in the UK press. Global Environmental Change, 19(2), 191-202. doi:10.1016/j.gloenvcha.2008.10.004. [abstract, full text]

Doyle, J. (2007). Picturing the clima (c) tic: Greenpeace and the representational politics of climate change communication. Science as Culture, 16(2), 129-150. [abstract, full text]

Dunlap, R. E. (1998). Lay Perceptions of Global Risk. International Sociology, 13(4), 473 -498. doi:10.1177/026858098013004004. [abstract]

Dutt, B., & Garg, K. C. (2000). An overview of science and technology coverage in Indian English-language dailies. Public Understanding of Science, 9(2), 123 -140. doi:10.1088/0963-6625/9/2/303. [abstract]

Duxbury, L. (2010). A Change in the Climate: New Interpretations and Perceptions of Climate Change through Artistic Interventions and Representations. Weather, Climate, and Society, 2(4), 294-299. doi:10.1175/2010WCAS1053.1. [abstract]

Ereaut, G., & Segnit, N. (2006). Warm Words: How Are We Telling the Climate Story and Can We Tell It Better? London: Institute for Public Policy Research. [abstract]

Fischhoff, B. (2007). Nonpersuasive Communication about Matters of Greatest Urgency: Climate Change. Environmental Science & Technology, 41(21), 7204-7208. doi:10.1021/es0726411 [abstract, full text]

Foust, C. R., & O’Shannon Murphy, W. (2009). Revealing and Reframing Apocalyptic Tragedy in Global Warming Discourse. Environmental Communication: A Journal of Nature and Culture, 3(2), 151. doi:10.1080/17524030902916624. [abstract, full text]

Füssel, H. (2009). An updated assessment of the risks from climate change based on research published since the IPCC Fourth Assessment Report. Climatic Change, 97(3-4), 469-482. doi:10.1007/s10584-009-9648-5. [abstract, full text]

Giannoulis, C., Botetzagias, I., & Skanavis, C. (2010). Newspaper Reporters’ Priorities and Beliefs About Environmental Journalism: An Application of Q-Methodology. Science Communication, 32(4), 425 -466. doi:10.1177/1075547010364927. [abstract]

Gordon, J. C., Deines, T., & Havice, J. (2010). Global Warming Coverage in the Media: Trends in a Mexico City Newspaper. Science Communication, 32(2), 143 -170. doi:10.1177/1075547009340336. [abstract, full text]

Grist, N. (2008). Positioning climate change in sustainable development discourse. Journal of International Development, 20(6), 783-803. doi:10.1002/jid.1496. [abstract]

Grundmann, R. (2006). Ozone and Climate. Science, Technology & Human Values, 31(1), 73 -101. doi:10.1177/0162243905280024. [abstract]

Grundmann, R., & Krishnamurthy, R. (2010). The Discourse of Climate Change: A Corpus-based Approach. Critical Approaches to Discourse Analysis Across the Disciplines, 4(2), 125-146. [abstract, full text]

Hamblyn, R. (2009). The whistleblower and the canary: rhetorical constructions of climate change. Journal of Historical Geography, 35(2), 223-236. doi:10.1016/j.jhg.2008.09.006. [abstract]

Hansen, A., & Machin, D. (2008). Visually branding the environment: climate change as a marketing opportunity. Discourse Studies, 10(6), 777 -794. doi:10.1177/1461445608098200. [abstract, full text]

Heath, Y., & Gifford, R. (2006). Free-Market Ideology and Environmental Degradation. Environment and Behavior, 38(1), 48 -71. doi:10.1177/0013916505277998. [abstract, full text]

Henderson-Sellers, A. (1998). Climate Whispers: Media Communication About Climate Change. Climatic Change, 40(3-4), 421-456. [abstract]

Holt, D., & Barkemeyer, R. (2010). Media coverage of sustainable development issues – attention cycles or punctuated equilibrium? Sustainable Development, n/a-n/a. doi:10.1002/sd.460. [abstract, full text]

Hulme, M. (2008). The conquering of climate: discourses of fear and their dissolution. The Geographical Journal, 174(1), 5-16. doi:10.1111/j.1475-4959.2008.00266.x. [abstract, full text]

Hulme, M. (2010). Mapping climate change knowledge: An editorial essay. Wiley Interdisciplinary Reviews: Climate Change, 1(1), 1-8. doi:10.1002/wcc.3. [abstract]

Ihlen, Ø. (2009). Business and Climate Change: The Climate Response of the World’s 30 Largest Corporations. Environmental Communication: A Journal of Nature and Culture, 3(2), 244. doi:10.1080/17524030902916632

Ioan, I., Zamfir, A., & Constantin, F. (2009). Oil Companies’ Climate Change Discourse. Case Study: Exxonmobil’s Discourse Analysis. Annals of Faculty of Economics, Annals of Faculty of Economics, 1(1), 337-342.

Kim, K. S.Public understanding of the politics of global warming in the news media: the hostile media approach. Public Understanding of Science. doi:10.1177/0963662510372313

Koteyko, N. (2010). Mining the internet for linguistic and social data: An analysis of ‘carbon compounds’ in Web feeds. Discourse & Society, 21(6), 655 -674. doi:10.1177/0957926510381220

Koteyko, N., Thelwall, M., & Nerlich, B. (2010). From Carbon Markets to Carbon Morality: Creative Compounds as Framing Devices in Online Discourses on Climate Change Mitigation. Science Communication, 32(1), 25 -54. doi:10.1177/1075547009340421

Kuha, M. (2009). Uncertainty about causes and effects of global warming in US news coverage before and after Bali. Language & Ecology, 2(4), 1–18.

Kurz, T., Augoustinos, M., & Crabb, S. (2010). Contesting the ‘national interest’ and maintaining ‘our lifestyle’: A discursive analysis of political rhetoric around climate change. British Journal of Social Psychology, 49(3), 601-625. doi:10.1348/014466609X481173

Kurz, T., Donaghue, N., Rapley, M., & Walker, I. (2005). The ways that people talk about natural resources: Discursive strategies as barriers to environmentally sustainable practices. British Journal of Social Psychology, 44(4), 603-620. doi:10.1348/014466604X18064

Ladle, R. J., Jepson, P., & Whittaker, R. J. (2005). Scientists and the media: the struggle for legitimacy in climate change and conservation science. Interdisciplinary Science Reviews, 30(3), 231-240. doi:10.1179/030801805X42036

Lever-Tracy, C. (2008). Global Warming and Sociology. Current Sociology, 56(3), 445 -466. doi:10.1177/0011392107088238

Liverman, D. M. (2009). Conventions of climate change: constructions of danger and the dispossession of the atmosphere. Journal of Historical Geography, 35(2), 279-296. doi:10.1016/j.jhg.2008.08.008

Livesey, S. M. (2002). Global Warming Wars: Rhetorical and Discourse Analytic Approaches to Exxonmobil’s Corporate Public Discourse. Journal of Business Communication, 39(1), 117-146. doi:10.1177/002194360203900106

Lorenzoni, I., Pidgeon, N. F., & O’Connor, R. E. (2005). Dangerous Climate Change: The Role for Risk Research. Risk Analysis, 25(6), 1387-1398. doi:10.1111/j.1539-6924.2005.00686.x

Lyytimäki, J., & Tapio, P. (2009). Climate change as reported in the press of Finland: From screaming headlines to penetrating background noise. International Journal of Environmental Studies, 66(6), 723. doi:10.1080/00207230903448490

Lyytimäki, Jari, (2011), Mainstreaming climate policy: the role of media coverage in Finland, Mitigation and Adaptation Strategies for Global Change, DOI: 10.1007/s11027-011-9286-x. [abstract]

Maibach, E., & Hornig Priest, S. (2009). No More “Business as Usual”. Science Communication, 30(3), 299 -304. doi:10.1177/1075547008329202

Major, A. M., & Atwood, L. E. (2004). Environmental Risks in the News: Issues, Sources, Problems, and Values. Public Understanding of Science, 13(3), 295 -308. doi:10.1177/0963662504044557

Manzo, K. (2010a). Imaging vulnerability: the iconography of climate change. Area, 42(1), 96-107. doi:10.1111/j.1475-4762.2009.00887.x

Manzo, K. (2010b). Beyond polar bears? Re-envisioning climate change. Meteorological Applications, 17(2), 196-208. doi:10.1002/met.193

Mazur, A., & Lee, J. (1993). Sounding the Global Alarm: Environmental Issues in the US National News. Social Studies of Science, 23(4), 681-720. doi:10.1177/030631293023004003

McCright, A. M., & Dunlap, R. E. (2000). Challenging Global Warming as a Social Problem: An Analysis of the Conservative Movement’s Counter-Claims. Social Problems, 47(4), 499-522.

McKnight, D. (2010). A change in the climate? The journalism of opinion at News Corporation. Journalism, 11(6), 693 -706. doi:10.1177/1464884910379704

McManus, P. A. (2000). Beyond Kyoto? Media Representation of an Environmental Issue. Australian Geographical Studies, 38(3), 306-319. doi:10.1111/1467-8470.00118

Miah, M. D., Kabir, M. H., Koike, M., & Akther, S. (2011). Major climate-change issues covered by the daily newspapers of Bangladesh. The Environmentalist. doi:10.1007/s10669-010-9305-6

Moore, M. P. (2009). The Union of Concerned Scientists on the Uncertainty of Climate Change: A Study of Synecdochic Form. Environmental Communication: A Journal of Nature and Culture, 3(2), 191. doi:10.1080/17524030902916657

Moser, S. C. (2010). Communicating climate change: history, challenges, process and future directions. Wiley Interdisciplinary Reviews: Climate Change, 1(1), 31-53. doi:10.1002/wcc.11

Moser, S. C., & Dilling, L. (Eds.). (2007). Creating a climate for change: communicating climate change and facilitating social change. Cambridge: Cambridge University Press.

Nerlich, B. (2010). ‘Climategate’: Paradoxical Metaphors and Political Paralysis. Environmental Values, 19(4), 419-442. doi:10.3197/096327110X531543

Nerlich, B., & Koteyko, N. (2009a). Carbon Reduction Activism in the UK: Lexical Creativity and Lexical Framing in the Context of Climate Change. Environmental Communication, 3(2), 206-223. doi:10.1080/17524030902928793

Nerlich, B., & Koteyko, N. (2009b). Compounds, creativity and complexity in climate change communication: The case of [`]carbon indulgences’. Global Environmental Change, 19(3), 345-353. doi:10.1016/j.gloenvcha.2009.03.001

Nerlich, B., & Koteyko, N. (2010). Carbon Gold Rush and Carbon Cowboys: A New Chapter in Green Mythology? Environmental Communication: A Journal of Nature and Culture, 4(1), 37.

Nerlich, B., Koteyko, N., & Brown, B. (2010). Theory and language of climate change communication. Wiley Interdisciplinary Reviews: Climate Change, 1(1), 97-110. doi:10.1002/wcc.2

Newell, P., & Paterson, M. (1998). A climate for business: global warming, the state and capital. Review of International Political Economy, 5, 679-703.

Nicholson-Cole, S. A. (2005). Representing climate change futures: a critique on the use of images for visual communication. Computers, Environment and Urban Systems, 29(3), 255-273. doi:10.1016/j.compenvurbsys.2004.05.002

Nisbet, M. C., & Myers, T. (2007). The Polls—Trends: Twenty Years of Public Opinion about Global Warming. Public Opinion Quarterly, 71(3), 1–27.

Nisbet, M. C., & Kotcher, J. E. (2009). A Two-Step Flow of Influence? Science Communication, 30(3), 328 -354. doi:10.1177/1075547008328797

Norgaard, K. M. (2006). “We Don’t Really Want to Know” Environmental Justice and Socially Organized Denial of Global Warming in Norway. Organization & Environment, 19(3), 347 -370. doi:10.1177/1086026606292571

Ockwell, D., Whitmarsh, L., & O’Neill, S. (2009). Reorienting Climate Change Communication for Effective Mitigation. Science Communication, 30(3), 305 -327. doi:10.1177/1075547008328969

O’Donnell, C., & Rice, R. E. (2008). Coverage of environmental events in US – and UK – newspapers: frequency, hazard, specificity, and placement. International Journal of Environmental Studies, 65(5), 637. doi:10.1080/00207230802233548

Olausson, U. (2010). Towards a European identity? The news media and the case of climate change. European Journal of Communication, 25(2), 138 -152. doi:10.1177/0267323110363652

O’Neill, S., & Nicholson-Cole, S. (2009). “Fear Won’t Do It”: Promoting Positive Engagement With Climate Change Through Visual and Iconic Representations. Science Communication. doi:10.1177/1075547008329201

Peters, H. P., & Heinrichs, H. (2008). Legitimizing climate policy: the “risk construct” of global climate change in the German mass media. International Journal of Sustainability Communication, 3, 14-36.

Pettenger, M. E. (Ed.). (2007). The Social Construction of Climate Change: Power, Knowledge, Norms, Discourses. Ashgate.

Reisigl, M., & Wodak, R. (2009). The Discourse-Historical Approach. In R. Wodak & M. Meyer (Eds.), Methods of critical discourse analysis (2nd ed., pp. 87-121). London: SAGE.

Revkin, A. C. (2007). Climate Change as News: Challenges in Communicating Environmental Science. In J. F. DiMento & P. Doughman (Eds.), Climate change: what it means for us, our children, and our grandchildren (pp. 139-160). Cambridge, MA: MIT Press. Retrieved from

Risbey, J. (2008). The new climate discourse: Alarmist or alarming? Global Environmental Change, 18(1), 26-37. doi:10.1016/j.gloenvcha.2007.06.003

Rogers-Hayden, T., Hatton, F., & Lorenzoni, I. (2011). [`]Energy security’ and [`]climate change’: Constructing UK energy discursive realities. Global Environmental Change, 21(1), 134-142. doi:10.1016/j.gloenvcha.2010.09.003

Rosa, E. A., & Dietz, T. (1998). Climate Change and Society. International Sociology, 13(4), 421 -455. doi:10.1177/026858098013004002

Russill, C.Truth and opinion in climate change discourse: The Gore-Hansen disagreement. Public Understanding of Science. doi:10.1177/0963662510364201

Ryghaug, M., Sørensen, K. H., & Næss, R.Making sense of global warming: Norwegians appropriating knowledge of anthropogenic climate change. Public Understanding of Science. doi:10.1177/0963662510362657

Sampei, Y., & Aoyagi-Usui, M. (2009). Mass-media coverage, its influence on public awareness of climate-change issues, and implications for Japan’s national campaign to reduce greenhouse gas emissions. Global Environmental Change, 19(2), 203-212. doi:10.1016/j.gloenvcha.2008.10.005

Scannell, L., & Grouzet, F. M. (2010). The metacognitions of climate change. New Ideas in Psychology, 28(1), 94-103. doi:10.1016/j.newideapsych.2009.09.020

Schweizer, S., Thompson, J. L., Teel, T., & Bruyere, B. (2009). Strategies for Communicating About Climate Change Impacts on Public Lands. Science Communication, 31(2), 266 -274. doi:10.1177/1075547009352971

Smith, J. (2005). Dangerous News: Media Decision Making about Climate Change Risk. Risk Analysis, 25(6), 1471-1482. doi:10.1111/j.1539-6924.2005.00693.

Smith, P. M. (2006). The Application of Critical Discourse Analysis in Environmental Dispute Resolution. Ethics, Policy & Environment, 9(1), 79. doi:10.1080/13668790500512548

Sonnett, J. (2010). Climates of risk: A field analysis of global climate change in US media discourse, 1997-2004. Public Understanding of Science, 19(6), 698 -716. doi:10.1177/0963662509346368

Stamm, K. R., Clark, F., & Eblacas, P. R. (2000). Mass communication and public understanding of environmental problems: the case of global warming. Public Understanding of Science, 9(3), 219 -237. doi:10.1088/0963-6625/9/3/302

Stocking, S. H., & Holstein, L. W. (2009). Manufacturing doubt: journalists’ roles and the construction of ignorance in a scientific controversy. Public Understanding of Science, 18(1), 23 -42. doi:10.1177/0963662507079373

Sundblad, E., Biel, A., & Gärling, T. (2009). Knowledge and Confidence in Knowledge About Climate Change Among Experts, Journalists, Politicians, and Laypersons. Environment and Behavior, 41(2), 281-302. doi:10.1177/0013916508314998

Szerszynski, B.Reading and Writing the Weather. Theory, Culture & Society, 27(2-3), 9 -30. doi:10.1177/0263276409361915

Takahashi, B. (2008). Framing climate change: A comparative analysis of a US and Canadian newspaper. International Journal of Sustainability Communication, 3, 152-170.

Thompson, M., & Rayner, S. (1998). Risk and Governance Part I: The Discourses of Climate Change. Government and Opposition, 33(2), 139-166. doi:10.1111/j.1477-7053.1998.tb00787.x

Trumbo, C. (1996). Constructing climate change: claims and frames in US news coverage of an environmental issue. Public Understanding of Science, 5(3), 269 -283. doi:10.1088/0963-6625/5/3/006

Trumbo, C. W., & Shanahan, J. (2000). Social research on climate change: where we have been, where we are, and where we might go. Public Understanding of Science, 9(3), 199 -204. doi:10.1088/0963-6625/9/3/002

Tsekos, C. A., & Matthopoulos, D. P. (2008). Environmental news in Greece: evaluation of the way newspapers deal with environmental issues. International Journal of Environmental Studies, 65(2), 209. doi:10.1080/00207230701832572

Ungar, S. (1992). The Rise and (Relative) Decline of Global Warming as a Social Problem. The Sociological Quarterly, 33(4), 483-501.

Ungar, S. (1995). Social scares and global warming: Beyond the Rio convention. Society & Natural Resources: An International Journal, 8(5), 443. doi:10.1080/08941929509380935

Ungar, S. (2000). Knowledge, ignorance and the popular culture: climate change versus the ozone hole. Public Understanding of Science, 9(3), 297 -312. doi:10.1088/0963-6625/9/3/306

Uusi-Rauva, C., & Tienari, J. (2010). On the relative nature of adequate measures: Media representations of the EU energy and climate package. Global Environmental Change, 20(3), 492-501. doi:10.1016/j.gloenvcha.2010.03.001

Wang, F. (2009). A Corpus-based Discourse Analysis of Global Warming in British, American and Chinese newspapers. In M. Mahlberg, V. González-Díaz, & C. Smith (Eds.), Proceedings of the Corpus Linguistics Conference CL2009. University of Liverpool, UK. Retrieved from

Watt, M. J. (2010). Has green news reporting gone green? An analysis of geographically diverse newspapers’ online and print coverage of climate change. First Monday, 15(10-4).

Weingart, P., Engels, A., & Pansegrau, P. (2000). Risks of communication: discourses on climate change in science, politics, and the mass media. Public Understanding of Science, 9(3), 261-283. doi:10.1088/0963-6625/9/3/304

Whitmarsh, L. (2009). What’s in a name? Commonalities and differences in public understanding of “climate change” and “global warming”. Public Understanding of Science, 18(4), 401 -420. doi:10.1177/0963662506073088

Whitmarsh, L., & Lorenzoni, I. (2010). Behaviour, perceptions, and communication of climate change. Wiley Interdisciplinary Reviews: Climate Change, n/a-n/a. doi:10.1002/wcc.7

Wilkins, L. (1993). Between facts and values: print media coverage of the greenhouse effect, 1987-1990. Public Understanding of Science, 2(1), 71 -84. doi:10.1088/0963-6625/2/1/005

Wilkins, L., & Patterson, P. (1991). Science as symbol: the media chills the greenhouse effect. In L. Wilkins & P. Patterson (Eds.), Risky business: Communicating issues of science, risk, and public policy (pp. 159–76). New York: Greenwood.

Wilson, K. M. (1995). Mass media as sources of global warming knowledge. Mass Comm Review, 22, 75-89.

Wilson, K. M. (2000a). Communicating climate change through the media. In S. Allan, B. Adam, & C. Carter (Eds.), Environmental risks and the media (pp. 201-217). London: Routledge.

Wilson, K. M. (2000b). Drought, debate, and uncertainty: measuring reporters’ knowledge and ignorance about climate change. Public Understanding of Science, 9(1), 1 -13. doi:10.1088/0963-6625/9/1/301

Wilson, K. M. (2002). Forecasting the Future. Science Communication, 24(2), 246 -268. doi:10.1177/107554702237849

Woods, R., Fernandez, A., & Coen, S.The use of religious metaphors by UK newspapers to describe and denigrate climate change. Public Understanding of Science. doi:10.1177/0963662510385061

Worthy, K. (2008). Modern Institutions, Phenomenal Dissociations, and Destructiveness Toward Humans and the Environment. Organization & Environment, 21(2), 148 -170. doi:10.1177/1086026608318987

Zehr, S. C. (2000). Public representations of scientific uncertainty about global climate change. Public Understanding of Science, 9(2), 85-103. doi:10.1088/0963-6625/9/2/301

Zhao, X. (2009). Media Use and Global Warming Perceptions. Communication Research, 36(5), 698 -723. doi:10.1177/0093650209338911

Zia, A., & Todd, A. M. (2010). Evaluating the effects of ideology on public understanding of climate change science: How to improve communication across ideological divides? Public Understanding of Science, 19(6), 743 -761. doi:10.1177/0963662509357871

Posted in Climate claims, Global warming effects | 6 Comments »

Papers on Cassiope tetragona as climate proxy

Posted by Ari Jokimäki on October 1, 2010

This is a list of papers on Cassiope tetragona as climate proxy. The list is not complete, and will most likely be updated in the future in order to make it more thorough and more representative.

UPDATE (February 5, 2013): Weijers et al. (2013) added.
UPDATE (April 4, 2012): Raybeck et al. (2012) added.

Reconstructing High Arctic growing season intensity from shoot length growth of a dwarf shrub – Weijers et al. (2013) “Annual shoot length of the circumarctic dwarf shrub Cassiope tetragona has proved to be a reliable proxy for past and ongoing climate change in the Arctic. This is based on its strong linear relationship with monthly climate parameters. Monthly means are, however, coarse units for prediction of growth in marginal regions with short growing seasons. An alternative to monthly averages are parameters that quantify the growing season length (GSL) and its intensity (growing degree-days; GDD5). GDD5 is defined as the cumulative daily mean temperature above 5°C. GSL is defined as the number of days on which the average temperature exceeds 5°C. The aims of this study were to test whether these parameters are a better predictor of growth than monthly means and to reconstruct past High Arctic growing season climate. Correlative analysis shows that GDD5 is a better predictor of annual shoot length growth than mean monthly temperatures and GSL, both at C. tetragona’s European northern and southern distribution limit, as well as at its assumed climatic optimum. Svalbard Airport GDD5 was reconstructed back to 1857. The reconstruction shares 61% of variance with the instrumental record. This opens the possibility to obtain an Arctic network of climate reconstructions with high temporal and spatial resolution through construction of C. tetragona shoot length chronologies.” Stef Weijers, Friederike Wagner-Cremer, Ute Sass-Klaassen, Rob Broekman, Jelte Rozema, The Holocene January 30, 2013 0959683612470178, doi: 10.1177/0959683612470178.

Multiproxy reconstructions of climate for three sites in the Canadian High Arctic using Cassiope tetragona – Raybeck et al. (2012) “We developed calibration models and reconstructed climate for sites in the central and eastern Canadian High Arctic using dendroclimatological and stable isotope analysis techniques on the dwarf-shrub, Cassiope tetragona. Our results may suggest complex temporal and spatial patterns of climate change in the region over the past century. For sites on Bathurst and Devon Islands, we reconstructed fall mean and June–July mean temperature using multiple linear regression analysis that explained 54 % and 40 % of the variance, respectively. The predictor variables included annual growth, annual production of leaves, flower buds and annual δ¹³C values for the Bathurst Island model, and annual growth and δ¹³C values for the Devon Island model. Both models revealed warmer than average temperatures throughout the mid-20th century, followed by a cooling trend from the early 1960s and mid-1970s at the Devon and Bathurst Island sites, respectively. Temperatures remained cool until the early 1980s and then increased until 1998/1999 at both sites. Our models are supported by other paleoclimate proxies and the instrumental record from the Canadian Arctic. For sites on Axel Heiberg and Bathurst Islands, we developed models using multivariate regresssion for February and March total precipitation that explained 44 % and 42 % of the variance, respectively. The Axel Heiberg Island model included annual production of flowers and flower buds, as well as annual δ¹³C values as predictor variables, while the Bathurst Island model only included the annual production of flower buds as a predictor. Both models showed lower than average precipitation from the early to mid-1900s, followed by increasing precipitation from the late 1980s to 1998/1999. Our precipitation models, supported by instrumental and proxy data, suggest a trend of increasing late-winter/early spring precipitation in the late 20th century. The lack of a single detectable climate signal across the study sites suggests local climate, topography, genetic variation and/or ecological conditions may dictate, in part, site responses and result in a heterogeneous climatescape over space and time. Yet, like other arctic paleoclimate proxies, chronology error and temporal discrepancies may complicate our interpretations. However, comparisons with other arctic proxies and the meteorological record suggest our models have also registered a regional climate signal.” Shelly A. Rayback, Gregory H. R. Henry and Andrea Lini, Climatic Change, DOI: 10.1007/s10584-012-0431-7.

Dendrochronology in the High Arctic: July air temperatures reconstructed from annual shoot length growth of the circumarctic dwarf shrub Cassiope tetragona – Weijers et al. (2010) “The instrumental Arctic climate record is both temporally and spatially limited. Therefore, there is a need for reliable climate proxies to increase knowledge of past and future Arctic climate change. Annual shoot length increase of the circumarctic dwarf shrub species Cassiope tetragona represents such a new climate proxy. We measured annual shoot length increase of 32 plant samples of the circumarctic dwarf shrub species C. tetragona using the presence of wintermarksepta within the stems, resulting in a 169 year growth chronology (1840–2008) for a High Arctic site on Svalbard. This is the longest growth chronology for dwarf shrub species produced up to now. Relationships between climate and Cassiope growth were investigated through correlative, response function and forward stepwise multiple regression analysis. July average air temperature was found to be the most important factor determining growth, by itself capable of explaining 41% of the variance in shoot growth between 1912 and 2008. The second best predictors were previous year September precipitation sums and average air temperatures, along with several previous growth parameters. A multiple regression model explaining growth with current July and previous year September temperature, combined with previous growth of lag 1, 2 and 5 years as predictors explains 70% of the observed variance in growth. July temperatures and previous year September precipitation sums alone explain 59% of the variance in standardized growth. Mean July air temperature was reconstructed for the period between 1876 and 2007 by a growth-temperature transfer model, using current and following year’s growth. The estimated temperatures correlated well with measured temperatures over the calibration (1912–1959) and verification (1960–2007) period: R2 = 0.34 and R2 = 0.47, respectively. The instrumental record (1912–2008) extended with these reliable mean July temperature estimates (1876–1911) reveals a significant warming trend on Svalbard since 1876 of 0.07 °C decade−1 on average. This study shows that the climate–growth relationships in C. tetragona, its longevity, its annual resolution, the availability of (sub)fossil fragments in tundra soil cores and its circumartic distribution make it a very valuable tool for climate reconstructions beyond the instrumental record and in areas lacking meteorological data, throughout the Arctic.” Stef Weijers, Rob Broekmana and Jelte Rozema, Quaternary Science Reviews, doi:10.1016/j.quascirev.2010.09.003.

Annual growth of Cassiope tetragona as a proxy for Arctic climate: developing correlative and experimental transfer functions to reconstruct past summer temperature on a millennial time scale – Rozema et al. (2009) “Annual growth of the polar evergreen shrub Cassiope tetragona on Svalbard was evaluated as a proxy for Arctic summer temperatures. Transfer functions were derived from temperature-growth correlations of shoots and from a temperature-growth response, obtained from experimental warming using open top chambers (OTC) in high Arctic tundra vegetation at Isdammen approximately 1.5 km southeast of Longyearbyen, Svalbard (78°N, 15 E) and in Longyeardalen, 3 km west of Isdammen from 2004 to 2006. Air temperatures, monitored throughout the summer months, were 1.3 °C higher inside the OTCs than in the control plots. Annual stem growth was measured by tagging stems and leaves, and in the lab with shoots harvested from OTCs and control plots. Annual growth parameters assessed were leaf production, sum of length and weight of individual leaves, and stem length increment derived from leaf scar distances and the distances between wintermarksepta in the stem. Wintermarksepta are formed at the end of the summer growth period when the pith is narrowing and consist of dense and dark tissue (Fig. 1b). The variation of annual growth in a 34-year site chronology (based on Cassiope shoots from the surroundings of the OTCs and control plots) correlated strongly with the mean summer temperature on Svalbard. The number of leaf pairs, leaf length and stem length also increased in the OTC warmed plots in the second and third year of warming. Transfer functions were derived from the temperature-annual growth correlations from a single shoot from Longyeardalen, from the cross-dated Isdammen site chronology and from the growth response to experimental warming. Based on leaf scar distances and distances between wintermarksepta of well-preserved subfossil shoots in arctic tundra soil, annual stem length increase was assessed for the layers of a soil core collected at the Isdammen site. Based on the derived transfer functions summer temperature of the period relating to the 15 cm deep tundra soil core layer, radiocarbon dated at 4230±40 bp, may have been 3.0 °C lower than the present-day 6.2 °C value. These results indicate that the transfer functions can be used to reconstruct past temperatures, beyond the time range of instrumental temperature and ice core records of Svalbard.” Jelte Rozema, Stef Weijers, Rob Broekman, Peter Blokker, Bert Buizer, Chantal Werleman, Hassan El Yaqine, Hanneke Hoogedoorn, Miguel Mayoral Fuertes, Elisabeth Cooper, Global Change Biology, Volume 15, Issue 7, pages 1703–1715, July 2009. [Full text]

Reconstruction of Summer Temperature for a Canadian High Arctic Site from Retrospective Analysis of the Dwarf Shrub, Cassiope tetragona – Rayback & Henry (2006) “We used retrospective analysis of the widespread evergreen dwarf-shrub, Cassiope tetragona, to reconstruct average summer air temperature for Alexandra Fiord, Ellesmere Island, Canada. Retrospective analysis is a technique based on dendrochronological methods. In this study, chronologies are based on the morphological characteristics of the plant stems. Two growth and two reproduction chronologies, ranging from 80 to 118 years long, were developed from each of two populations at the High Arctic site. We used multiple regression models to develop a 100-year-long (1895-1994) reconstruction of July-September average air temperature that explained 45% of the climatic variance in the instrumental record. The reconstruction revealed an increase in summer temperature from ~1905 to the early 1960s, a cooling trend from the mid-1960 to the 1970s, and an increase in temperature after 1980. These historical temperature patterns correspond well with those from other climate proxies from sites on Ellesmere and Devon Islands. As well, the similarity between our model and an arctic-wide proxy temperature time series suggests that the Cassiope-based reconstruction contains a large-scale temperature signal. There is great potential for the development of proxy climate data using Cassiope tetragona from sites throughout the Arctic.” Shelly A. Rayback, Gregory H. R. Henry, Arctic, Antarctic, and Alpine Research, Volume 38, Number 2 / May 2006, 228-238.

Dendrochronological Potential of the Arctic Dwarf-Shrub Cassiope tetragona – Rayback & Henry (2005) “In this report, we describe the use of dendrochronological techniques on the circumpolar, evergreen dwarf-shrub, Cassiope tetragona. Using techniques such as crossdating and standardization, and the software programs COFECHA and ARSTAN, we developed C. tetragona growth and reproduction chronologies for sites in the Canadian High Arctic. High-resolution chronologies may be used to reconstruct past climate and phase changes in large-scale modes of atmospheric circulation (e.g. Arctic Oscillation, North Atlantic Oscillation), to investigate the growth and reproductive responses of the plant to ambient and manipulated environmental variables, and to reconstruct the plant’s past ecohydrology (δ18O, δD, δ13C), gas exchange (δ13C) and mineral nutrition (δ15N). As C. tetragona is a circumpolar species, chronologies may be developed throughout the Arctic at sites where no trees exist, and thus provide new information on the past climate and environmental history of sites and regions previously unstudied.” Shelly A. Rayback and Gregory H. R. Henry, Tree-Ring Research 61, 1):43-53. 2005, doi: 10.3959/1536-1098-61.1.43. [Full text]

Arctic and North Atlantic Oscillation phase changes are recorded in the isotopes (δ18O and δ13C) of Cassiope tetragona plants – Welker et al. (2005) “The Arctic and North Atlantic Oscillations (AO/NAO) are large-scale annual modes of atmospheric circulation that have shifted in the last 30 years. Recent changes in arctic climate, including increasing surface air temperature, declining sea ice extent, and shifts in the amounts seasonality of precipitation are linked to the strong positive phase of the AO/NAO. Here, we show that phase changes in the AO/NAO are recorded in the isotopic (δ18O and Δ-carbon isotope discrimination) characteristics of the long-lived circum-arctic plant, Cassiope tetragona, as summer rain has become a more important water source than snowmelt water which in turn has lead to decreases in Δ and reductions in plant stem growth. These isotopic records in C. tetragona may facilitate reconstructions of climate, plant–soil water relations, plant gas exchange attributes and a mechanistic understanding of growth responses to shifts in atmospheric circulation. If plant specimens were available for populations across the arctic as part of the International Polar Year, these archives could provide a circum-arctic record of historical climate change and associated shifts in physiological plant performance and growth.” Jeffrey M. Welker, Shelly Rayback, Greg H. R. Henry, Global Change Biology, Volume 11, Issue 7, pages 997–1002, July 2005.

Responses to natural climatic variation and experimental warming in two tundra plant species with contrasting life forms: Cassiope tetragona and Ranunculus nivalis – Molau (1997) “Two circumpolar tundra plant species, the evergreen dwarfshrub Cassiope tetragona and the perennial herb Ranunculus nivalis, were studied at Latnjajaure in northern Swedish Lapland during three consecutive growing seasons (1993–95) as a contribution to the ITEX programme. Open-top chambers (OTCs) were used in a passive heating experiment, and the performance of the plants in unmanipulated controls was correlated with climatic fluctuations among the years. Phenological, vegetative, and reproductive variables were measured. In both species phenological responses were controlled mainly by ambient air temperature. In the evergreen C. tetragona vegetative growth was controlled mainly by the influx of global solar radiation and was not temperature-dependent, whereas the opposite applied in the herbaceous R. nivalis. Vegetative growth in C. tetragona was rather stable among years as well as between treatments, whereas it was strongly influenced by annual climate in R. nivalis. Both species increased their reproductive success with increasing temperature, but R. nivalis was also radiation-dependent in this case, probably because of its green, photosynthetic nutlets. Ovule number in R. nivalis increased steadily in the experimentally heated plots during the study in response to the constant temperature amelioration above the ambient. At the community level, evergreen C. tetragona seems to have low competitive ability under warmer conditions. The situation for vernal low-growing herbs like R. nivalis is more complex; despite a strong positive response to increased temperature, they may exhibit decreased reproductive success if overgrown by a vigorous graminoid canopy.” U. Molau, Global Change Biology, Volume 3, Issue S1, pages 97–107, December 1997.

Retrospective Analysis of Growth and Reproduction in Cassiope tetragona and Relations to Climate in the Canadian High Arctic – Johnstone & Henry (1997) “Techniques of retrospective growth analysis, adapted from dendrochronology, were applied to Cassiope tetragona, an evergreen dwarf-shrub, sampled at Alexandra Fiord. Ellesmere Island, Canada. A new method of delimiting annual growth increments through patterns in leaf node placement along a stem was utilized. Chronologies of mean annual stem elongation, leaf production, and flower production were developed, and estimates of these parameters agree with those obtained for other arctic populations of C. tetragona. Stem elongation and leaf production were positively correlated in the same year. Flower production was positively correlated with growth in the previous year, but negatively correlated with growth in the same year. This pattern was interpreted as the effects of resource allocation strategies, namely, the preemption of within-plant resources by flower production once flowering is initiated. All chronologies were significantly correlated with climate records from Alexandra Fiord and Eureka, Ellesmere Island, with the majority of significant correlations occurring with June and July temperatures. Flower production appeared to be most sensitive to variations in summer temperatures, and climate response functions which included previous growth explained up to 84% of the variation in the flowering chronology. Unstandardized leaf and flower number chronologies were used to provide an independent test of the climate transfer function presented in Havström et al. (1995). The results indicate that C. tetragona may be used successfully to generate proxy climate data, although use of standardized chronologies is recommended. Two predictive models for July temperatures at Alexandra Fiord, based on standardized chronologies, are presented to provide future opportunities for verification and application of this technique.” Jill F. Johnstone and Greg H. R. Henry, Arctic and Alpine Research, Vol. 29, No. 4 (Nov., 1997), pp. 459-469.

Little Ice Age Temperature Estimated by Growth and Flowering Differences between Subfossil and Extant Shoots of Cassiope tetragona, an Arctic Heather – Havström et al. (1995) “1. A unique opportunity to study conditions for plant growth at the onset of glaciation was offered as a retreating glacier at Ellesmere Island, Canada, revealed well-preserved, subfossil plants (411±70 radio-carbon years old) of Cassiope tetragona, an arctic dwarf-shrub previously used to study climate-related growth of modern plants. 2. Growth and flowering of the ancient and modern shoots of C. tetragona from the same locality were examined retrospectively. The ancient shoots produced leaves in each, and flowers in each except one, of the last 26 years before they died, although this production was significantly lower and less variable among years than in the modern shoots. 3. Predictions based on regression between modern plant performance and climatic data from the study site imply that the mean July temperature of the period immediately preceding the glaciation of the area was about 0.7⚬C lower than today. This estimate is independently supported by the correlation between growth and mean July temperature seen today among different sites. 4. The results support the idea that the pre-Little Ice Age plants were killed suddenly by permanent snow embedment and not by glacial movements or temperature limitations as such.” M. Havstrom, T. V. Callaghan, S. Jonasson and J. Svoboda, Functional Ecology, Vol. 9, No. 4 (Aug., 1995), pp. 650-654.

Differential Growth Responses of Cassiope tetragona, an Arctic Dwarf-Shrub, to Environmental Perturbations among Three Contrasting High- and Subarctic Sites – Havström et al. (1993) “Three populations of Cassiope tetragona (Ericaceae) were subjected to in situ environmental perturbations simulating predictions of global warming. The populations were selected to represent different parts of the range of the species, one growing in a high arctic coastal heath at Ny-Ålesund (Svalbard, northern part of the species’ range), one at a subarctic fellfield at 1150 m a.s.l. at Abisko, Swedish Lapland, and one in a subarctic tree-line heath at 450 m a.s.l. at Abisko, southern part of the species’ range. The manipulations included nutrient addition, shading and two levels of temperature enhancement using passive greenhouses. The micrometeorological effects of the shading treatment was similar to that of a mountain birch canopy and the temperature enhancement treatments had the desired effect to increase the average air temperature by 2-4°C. Greenhouses which had a gap between the soil and the greenhouse plastic were particularly successful in creating the desired climatic perturbation without causing extreme maximum temperatures or other unwanted side-effects. The environmental manipulations caused strikingly different responses in the vegetative growth pattern of main shoots of C. tetragona among the three populations: at the subarctic tree-line heath, nutrient addition caused a substantial increase in growth, whereas it was the temperature enhancement treatments that caused increases, although smaller, at the subarctic fellfield and the high arctic heath sites. At the high arctic site, we also found growth reduced in response to shading, but at the subarctic sites, and particularly at the tree-line heath site, shading caused a marked etiolation of the shoots. Hence, different factors seem to produce very different responses in the vegetative growth of C. tetragona in different parts of its geographical range. We conclude that competition for nutrients and light are the main limiting factors for the growth of Cassiope tetragona near the lower distributional limit (LODIL) of the species, but that temperature is the main limiting factor in the northern parts of its range, and at high altitudes in the southern parts of its range. We also suggest that the direct effect of predicted future climatic warming on the growth of Cassiope tetragona will increase towards the north, whereas a possible indirect effect of increasing nutrient availability following a temperature increase will be the main effect in the southern and lower parts of its range. These responses could, however, be modified by shading from other species responding to environmental change by increased growth.” Mats Havström, Terry V. Callaghan and Sven Jonasson, Oikos, Vol. 66, No. 3 (Apr., 1993), pp. 389-402.

Historical Records of Climate-Related Growth in Cassiope Tetragona from the Arctic – Callaghan et al. (1989) “(1)Shoots of the circumpolar species Cassiope tetragona were collected on brief visits to three remote arctic and subarctic sites, two in Svalbard and one in Swedish Lapland. The shoots were subsequently analysed by measuring leaf lengths in strict sequence along individual shoots. (2) This evergreen species retained up to 232 leaves per shoot. Leaf lengths, plotted against leaf position on the shoots, revealed two trends: (i) more or less regular waves caused by the alternation of short spring and autumn leaves with long summer leaves, and (ii)an ontogenetic trend represented by a general increase in leaf length with increasing distance between the point of origin of the leaf and the crigin of the shoot. (3) The seasonal trend of leaf length was used to delimit annual complements of leaves, of which up to twenty persisted. The number of leaves was counted for each year and the ontogenetic trend of leaf length was removed by statistical methods so that leaf length indices could be calculated and relative lengths compared, both between years within populations and between populations. Three indices of leaf length were derived: maximum, minimum and the total of all leaf length indices for each year. (4)Correlation analysis between the four measures of annual leaf performance showed several similarities between the two Svalbard populations, a few between the low altitude population from Svalbard and that from Swedish Lapland and none between the higher altitude Svalbard population and that from Swedish Lapland. (5) Correlation analysis between annual leaf performance and mean monthly temperature and monthly total precipitation showed that July temperatures and precipitation during May were particularly important for leaf development in the Svalbard populations. July temperatures represent mid-summer conditions during a very short growing season in Svalbard, whereas May is normally the driest month in this region of generally low precipitation. Ambient temperature is usually sub-zero for most of May and precipitation as snow is probably important in protecting the sensitive shoot apices of C. tetragona which lack true buds. (6) In Swedish Lapland, the number of leaves per year was correlated with summer temperatures but only negatively with precipitation which was greater at the Swedish site than in Svalbard. At the Swedish site, therefore, the protection of leaf primordia from frost is probably greater than in Svalbard because of a more persistent snow cover. (7) Correlations between the number of leaves per year and leaf length indices in the previous year, together with correlations between leaf performance and weather conditions in the previous year, were often significant. In general, the same weather variables were correlated with leaf performance as in the within-year comparisons. (8) The correlations between the number of leaves per year and the other measures of leaf performance and weather in the previous year were particularly strong in the Svalbard populations. This demonstrates the preformation of an annual leaf complement by the High Arctic Svalbard populations. This may be an important mechanism to buffer production against particularly adverse weather conditions during the growing season. Leaf preformation was apparent but not so clearly demonstrated at the subarctic-alpine Swedish site. (9) Significant multiple regression models of leaf performance were obtained in ten out of the twelve cases. Five models accounted for more than 50% of the variation in leaf performance and two of these accounted for more than 65%. The most significant relationships were found for total leaf length index at the two Svalbard sites and number of leaves per year at the Swedish site. Weather variables in the preceding year, particularly precipitation in May, were usually represented in the models. (10) Retrospective analysis of the historical records of growth preserved in ungrazed herbaceous material from the Arctic can lead to the dating of specific events and the construction of models of long-term climate-related growth even though the period spent in the field is brief.” T. V. Callaghan, B. A. Carlsson and N. J. C. Tyler, Journal of Ecology, Vol. 77, No. 3 (Sep., 1989), pp. 823-837. [Full text]

Posted in Climate science | 2 Comments »

%d bloggers like this: