Copenhagen Diagnosis

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The Copenhagen Diagnosis is a report written by twenty-six climate scientists from eight countries.[1][2] It was published in 2009 and was a summary of the peer-reviewed literature to date.[3][4]

The Copenhagen Diagnosis is a follow-up of the previous Intergovernmental Panel on Climate Change’s Working Group 1 Report.[5][6] The studies summarized, which date back to the cutoff point of the Working Group 1 Report, are those that authors viewed most relevant to the discussions at the 2009 United Nations Climate Change Conference.[5] The Copenhagen Diagnosis served as the midpoint between IPCC –AR4 and IPCC-AR5.[6]

In total, the Copenhagen Diagnosis contains eight main sections, which are:

  1. Surging Greenhouse gas emissions
    • Since 1990, the combined global emission of carbon dioxide from various origins, such as cement production, deforestation, and fossil fuel burning, has increased 27%.
  2. Human-induced warming
    • Studies conducted by Lee and Rind show that only 10% of global warming over the past century was due to the Sun.
  3. Acceleration of melting ice caps
    • Glaciers and melting ice caps can contribute to about 8/10ths of a meter to global sea level rise.
  4. Rapid Arctic sea-ice decline
    • According to simulations run by NCAR Climate System Model version 3, the Arctic summer is expected to be ice-free by 2040.
  5. Underestimation of changing sea levels
    • In contrast to previous IPCC, the rate of sea level rise (3.4 mm/yr over the past 15 years) has increased around 80% faster than previously predicted.
  6. Damage due to inaction
    • A region of permafrost, called the Yedoma, stores about 500 Gt of CO2 and, once released due to rising global temperatures, will increase global temperatures even more.
  7. Turning point must come soon
    • The largest climate science conference, held in 2009, has stated, “Temperature rises above 2 °C will be difficult for contemporary societies to cope with, and are likely to cause major societal and environmental disruptions through the rest of the century and beyond.”
  8. The Future
    • By 2100, global mean air-temperature is projected to warm by 2°C – 7°C above pre-industrial levels.


  1. ^ "How the Copenhagen Diagnosis came to be written". The Copenhagen Diagnosis. 
  2. ^ Lee, Mike (2009-11-24). "Climate scientists offer grim 'Diagnosis'". San Diego Union-Tribune. 
  3. ^ Sale, Peter (2011). Our Dying Planet: An Ecologist's View of the Crisis We Face. University of California Press. p. 95. ISBN 978-0-520-26756-5. 
  4. ^ "'Copenhagen Diagnosis' offers a grim update to the IPCC's climate science". The Guardian. London. 25 November 2009. Retrieved 6 September 2011. 
  5. ^ a b "Copenhagen". Real Climate: Climate science from climate scientists. Retrieved 12 December 2011. 
  6. ^ a b "'Copenhagen Diagnosis' offers a grim update to the IPCC's climate science". Guardian Environment Network. London: The Guardian. 25 November 2009. 

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