I wonder how many of us have watched Al Gore’s film An Inconvenient Truth and thought "wow, that really is terrifying, I’d better start making a few changes". And more to the point, how many of us have then done something about it. If you’re like Sarah and you’ve started cycling to the supermarket, well done, Al Gore would be proud of you!
But what do the scientists think of An Inconvenient Truth (AIT)? Sensationalism or accuracy? Informing the public or misinforming the public? A forum published in GeoJournal looked at these questions and asked the scientists what they thought of the film documenting Al Gore’s campaign to educate the public about global warming and inspire them to take action.
The focus of the forum was to address whether AIT accurately presents the scientific argument that global warming is caused by human activities. 4 authors were asked to write papers and there were a number of common themes, including:
- AIT does an excellent job of raising public awareness of anthropogenic global warming and explaining why increased atmospheric concentrations of greenhouse gases leads to warming.
- One of the main weaknesses of AIT is that it tries to use individual events (e.g. Hurricane Katrina) to prove that global warming is occurring.
- By presenting the temperature history from the ice core records alongside the CO2 concentrations Gore implied that the temperature change will be much larger than is projected by climate models.
- Al Gore only discusses anthropogenic causes of climate change and does not describe important natural causes e.g. those attributed to orbital variations, volcanic activity and solar forcing.
Despite these common themes, there were varied perspectives on AIT from the 4 authors (for more details see the abstracts at the end of this blog).
- "Another look at An Inconvenient Truth", Steig: the factual errors that are present in the film are inconsequential and do not undermine the main message of the film, that human activities will cause greater climate change in the future and this places important moral and ethical choices before society.
- "An Inconvenient Truth: blurring the lines between science and fiction", Spencer: the true state of knowledge about global warming is much less certain than is portrayed in AIT. Interpretations are biased. Gore uses extreme events (e.g. hurricanes and tornadoes) to prove global warming. There is a mix up of cause and effect in Gore’s graphical portrayal of temperature and CO2 variations. Science has no idea how much of recent warming is natural versus the result of human activities.
- "An Inconvenient Truth: a focus on its portrayal of the hydrologic cycle", Legates: observational data fail to support many of the claims made in AIT and there is a bias in AIT toward catastrophe scenarios which it claims have increased due exclusively to anthropogenically-driven climate change. Alarmism and exaggeration cause significant errors in the film.
- "An Inconvenient Truth: the scientific argument", Nielsen-Gammon: Gore does an excellent job of conveying the relevant scientific information in a memorable way. The most serious flaw is that Gore never provides model-based projections of future global temperature increases but instead encourages the audience to make their own projections based on the temperature and CO2 graphs. The reliance on observed data and recent events, although effective, leads the audience to incorrectly believe that every recent drought, flood, and hurricane is a consequence of global warming – this increases the emotional impact of AIT but decreases the validity of the scientific argument.
The overall view of AIT, summarised by North in the final paper of the forum, is that "there are some inaccuracies and exaggerations in AIT, but on the whole it represents mainstream scientific views on global warming… There is a large body of scientists who are adherents to the paradigm and there does not appear to be any serious alternative at this time."
AIT is an accessible and emotionally powerful means of communicating scientific knowledge to the general public, but don’t take the scientific statements in the film too seriously – next time we have floods in summer don’t automatically blame it on human-caused global warming, it may just be a result of natural climate fluctuations. But as long as we’re unsure of the effect of humans on the climate, why take the risk? We may as well start doing what we can to limit our detrimental impact on the environment in what little ways we can now in our own lives. Maybe a little alarmism in AIT will be successful in making us more aware of this. And who knows, leaving the car behind every now and then may do wonders for your waistline as well as your bank account! For the real science behind the global warming theory, I recommend going to the original IPCC reports.
Abstracts of the forum papers, available through Springer:
Eric J. Steig (2007) Another look at An Inconvenient Truth. GeoJournal 70 (1), 5-9.
Published online: 15 March 2008
Abstract: The portrayal of the science of climate change in An Inconvenient Truth is largely correct. Some aspects of the film, such as the discussion of Hurricane Katrina, oversimplify the complex factors involved, while others conflate global warming with other environmental changes that may not be related. However it is not in question that continuing emissions of greenhouse gases by human activities will cause greater climate change in the future, and that the impacts of such change are likely to be negative. The chief message of the film—that this fact places important moral and ethical choices before society—is therefore an accurate one.
Roy W. Spencer (2007) An Inconvenient Truth: blurring the lines between science and science fiction. GeoJournal 70 (1), 11-14.
Published online: 19 March 2008
Abstract; Al Gore’s movie An Inconvenient Truth gives a variety of unusually biased interpretations of the state of climate science and global warming theory. These cover a wide range of natural events and processes which could potentially be impacted by global warming, but which the movie misrepresents as clear examples of the human influence on climate. A few examples include the mixing up of cause and effect in his graphical portrayal of temperature and carbon dioxide variations over hundreds of thousands of years; the repeated depiction of ice calving from glaciers as a sign of global warming; the implication that Hurricane Katrina was the fault of humans; and the particularly extreme view that the Greenland ice sheet will melt, flooding coastal cities worldwide. Ultimately, all of these are related to the widespread perception that scientists have uniquely tied global warming to anthropogenic greenhouse gas emissions. The real inconvenient truth is that science has no idea how much of recent warming is natural versus the result of human activities.
David R. Legates (2007) An Inconvenient Truth: a focus on its portrayal of the hydrologic cycle. GeoJournal Volume 70 (1), 15-19.
Published online: 21 March 2008
Abstract: 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’.
John W. Nielsen-Gammon (2007) An Inconvenient Truth: the scientific argument. GeoJournal 70 (1), 21-26.
Published online: 18 March 2008
Abstract: The movie An Inconvenient Truth is a powerful portrayal of global warming and its impacts. The main scientific argument presented in the movie is for the most part consistent with the weight of scientific evidence, but with some of the main points needing updating, correction, or qualification. The detailed argument relies almost entirely on past and current evidence and neglects almost all information that can be gained from computer models, perhaps because such information would be difficult for a lay audience to grasp, believe, or connect with emotionally. This places an undue weight on current events as signs of ongoing climate change: some such events are apparently not related at all to climate change, while for other specific events the role of global warming is difficult or impossible to establish.
Gerald R. North (2007) An Inconvenient Truth and the scientists. GeoJournal Volume 70 (1), 27-31.
Published online: 18 March 2008
Abstract: An Inconvenient Truth provides an opportunity to examine the differences between scientific statements and the mixed statements made by politicians. The Gore movie is a powerful example of the latter. There are some inaccuracies and exaggerations in the film, but on the whole it represents mainstream scientific views on global warming. This essay looks into the state of the art of climate change research including its scientific underpinnings. Climate science is in a state of ‘normal science’ as discussed by Kuhn. There is a large body of scientists who are adherents to the paradigm and there does not appear to be any serious alternative at this time.
Interested in the impact of humans on the environment, including climate change? Find out more about Environmental Impact at www.cabi.org/environmentalimpact – our new internet resource coming soon to a screen near you!