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Inside the Greenhouse

Statement of Method

updated November 2023

We monitor 131 sources (across newspapers, radio and TV) in 59 countries in seven different regions around the world. We assemble the data by accessing archives through Factiva, Infomedia, ProQuest, Nifty and NexisUni databases for our work across our various institutions. These sources are selected through a decision process involving the weighting of three main factors:

  1. geographical diversity (favoring a greater geographical range)
  2. circulation (favoring higher circulating publications)
  3. reliable access to archivesT over time (favoring those accessible consistently for longer periods of time)


Through Nexis Uni, we search these sources (listed alphabetically): The Age (Australia), The Australian (Australia), Business Day (South Africa), The Citizen (United Republic of Tanzania), The Courier-Mail (Australia), Daily Trust, (Nigeria), Daily Mail (Mail on Sunday) (United Kingdom), Daily Nation (Kenya), The Daily Telegraph & Sunday Telegraph (Australia), The Dawn (Pakistan), Dominion Post (New Zealand), The Express and Express on Sunday (United Kingdom), The Globe and Mail (Canada), The Guardian and Observer (United Kingdom), Gulf Daily News (Bahrain), The Herald (Zimbabwe), The Irish Times (Ireland), The Jerusalem Post (Israel), The Korea Times (South Korea), The Los Angeles Times (United States), The Daily Mirror (and Sunday Mirror) (United Kingdom), The Daily Mirror (Sri Lanka), The Daily News (Sri Lanka), The Malaysian Reserve (Malaysia), The Nation (Thailand), National Post (Canada), The New Era (Namibia), The New Nation (Bangladesh), The New Straits Times (Malaysia), The New Times (Rwanda), The New York Times (United States), New Zealand Herald (New Zealand), Philippines Daily Inquirer (Republic of the Philippines), The Prague Post (Czech Republic), The Press (New Zealand), The South China Morning Post (China), The Straits Times (Singapore), The Sun and The Sun on Sunday (United Kingdom), Sydney Morning Herald (Australia), The Telegraph and Telegraph on Sunday (United Kingdom), The Times and Times on Sunday (United Kingdom), The Times of Zambia (Zambia), The Toronto Star (Canada), USA Today (United States), Vanguard (Nigeria), The Wall Street Journal (United States), and The Washington Post (United States). We use the Boolean string ‘climate change or global warming’ and the date ranges as well as individual sources selected through the ‘advanced options’ function. For all searches through the Nexis Uni database, the default option for duplicates was chosen.

Through Factiva, we search these sources (listed alphabetically): The Bangkok Post (Thailand), Daily Star (Lebanon), Die Tageszeitung (Germany), El Pais (Spain), El Mercurio (Chile), The Hindu (India), Hindustan Times (India), The Indian Express (India), The Jakarta Post (Indonesia), Japan News (Japan), La Nacion (Argentina), Manila Bulletin (Philippines), The Nation (Pakistan), O Globo (Brazil), The Saigon Times Daily (Vietnam), Süddeutsche Zeitung (Germany), The Times of India (India), and Today (Singapore). We use the Boolean string ‘climate change or global warming’ and the date ranges as well as individual sources selected for all English-languages searches. For all English-language searches through the Factiva database, the default option for duplicates was chosen. For German speaking sources, we conduct searches using the following translation, “Klimawandel” or “Globale Erwärmung. For Spanish speaking sources, we conduct individual searches for ‘calentamiento global’ or ‘cambio climático’ and then manually search for, and eliminate duplicates.

National-level counts in Japan are undertaken by Midori Aoyagi, from the National Institute for Environmental Sciences (NIES) in Japan. The Fujitsu Limited "G-search" database is used to monitor coverage in Asahi Shimbun, Yomiuri Shimbun and Mainichi Shimbun through the search terms ‘climate change’, ’global warming’, or ‘greenhouse effect, from January 2000 through the present. National-level counts in Spain and Latin America are undertaken by Rogelio Fernández Reyes, member of the research group GREHCCO of the Universidad de Sevilla, and member of the research group MDCS of the Universidad Complutense de Madrid. Rogelio uses My News database (a referent provider of journalistic documentation in Spain) to monitor coverage in El Mundo, La Vanguardia and Expansión through the search terms ‘‘calentamiento global’ or ‘cambio climático’.

International and national-level counts in Australia, Canada, India, New Zealand, the United Kingdom and the United States are undertaken by Maxwell Boykoff, Andrew Benham, Meaghan Daly, Rogelio Fernández-Reyes, Lucy McAllister, Marisa McNatt, Ami Nacu-Schmidt, David Oonk, and Olivia Pearman. National-level counts in each of these countries begin in January 2000 with the exception of the following: Dominion Post (July 2002). International counts of the fifty-two noted sources begin in January 2004 with the exception of the following: El Nacional (December 2007); Indian Express (December 2007); The Nation (Pakistan) (June 2004); Gulf Daily News (Bahrain) (May 2008); Philippine Daily Inquirer (September 2004); Ghanaian Chronicle (January 2010); The Herald (Zimbabwe) (January 2010).

To arrive at comparable assessments of numbers of articles per month per source, we take the total number of articles each month in each region and divide by the number of sources searched during that month. For the archives that become available after the starting date of January 2004, this denominator changes over time. As some regions contain more sources than others, this 'normalization' process then provides a useful metric for comparisons across regions.

MeCCO Research Team

Midori Aoyagi1, Anne Gammelgaard Ballantyne8, Max Boykoff2, Catherine Bruns11, Patrick Chandler2, Meaghan Daly2, Rogelio Fernández-Reyes4, Erin Hawley6, Yumiko Hayakawa1, Kyotaek Hwang15, Isidro Jiménez Gómez5, Kyungsun Lee3, Jari Lyytimäki10, Lucy McAllister9, Erkki Mervaala10, Gabi Mocatta12, Ami Nacu-Schmidt2, David Oonk13, Jeremiah Osborne-Gowey2, Olivia Pearman14, Lars Kjerulf Petersen8, Anne Hege Simonsen7, and Andreas Ytterstad7

1National Institute for Environmental Studies, Japan, 2University of Colorado Boulder, USA, 3University of Arkansas, Little Rock, USA, 4Universidad de Sevilla, Spain, 5Universidad Complutense de Madrid, Spain, 6University of Tasmania, Australia, 7Oslo Metropolitan University, Norway, 8Aarhus University, Denmark, 9Denison University, USA, 10Finnish Environment Institute, Finland, 11University of Minnesota, USA, 12Deakin University, Australia, 13US Department of Energy, USA, 14US Geological Survey, USA, 15University of New Mexico, USA

MeCCO Lead Team

MeCCO lead Project Investigator, Max Boykoff
MeCCO Infographics, Design & Outreach Lead, Ami Nacu-Schmidt
MeCCO Counts Coordinator & Technical Support Lead, Olivia Pearman

MeCCO is a Multi-University Collaboration

University of Colorado Boulder (USA), Aarhus University (Denmark), Deakin University(Australia), Denison University (USA), National Institute for Environmental Studies (Japan), Oslo Metropolitan University (Norway), Universidad de Sevilla (Spain), University of Tasmania (Australia), University of Arkansas, Little Rock (USA), Universidad Complutense de Madrid (Spain), Finnish Environment Institute (Finland), US Department of Energy (USA), US Geological Survey (USA) and University of Minnesota (USA)