An Inconvenient Truth: a focus on its portrayal of the hydrologic cycle


An Inconvenient Truth (AIT) has earned Al Gore an Oscar and a share of the 2007 Nobel Peace Prize and has been widely acclaimed by the mass media. However, significant errors exist in the film, owing to alarmism and exaggeration. As this forum does not provide for a detailed examination of these errors, this paper will focus only on the portrayal of the hydrologic cycle by AIT—precipitation and floods, soil moisture and droughts, and storminess. AIT argues that precipitation and intense rainfalls, floods, droughts, and the total number, intensity, and duration of tropical cyclones have all increased due exclusively to anthropogenically-driven climate change; indeed, AIT paints a picture of near scientific certainty with an overwhelming bias toward catastrophe scenarios. A closer look at the science, however, reveals that the data do not support these claims and that the scientific community is divided as to what the impact of anthropogenic climate change on the hydrologic cycle will be. Thus, the film gives a false impression of both the current state of climate change and that ‘the science is settled’.

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    An unofficial transcript of the film was obtained from

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Correspondence to David R. Legates.

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Legates, D.R. An Inconvenient Truth: a focus on its portrayal of the hydrologic cycle. GeoJournal 70, 15–19 (2007).

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  • An Inconvenient Truth
  • Climate change
  • Droughts
  • Floods
  • Hydrologic cycle
  • Precipitation
  • Soil moisture