Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.


Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup


All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Bluesky Facebook LinkedIn Mastodon MeWe

Twitter YouTube RSS Posts RSS Comments Email Subscribe

Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...

New? Register here
Forgot your password?

Latest Posts


Ten years on: how Al Gore's An Inconvenient Truth made its mark

Posted on 30 May 2016 by John Cook

The ConversationThis article was originally published on The Conversation. Read the original article.

Ten years ago, An Inconvenient Truth opened in cinemas in the United States.

Starring former US vice president Al Gore, the documentary about the threat of climate change has undoubtedly made a mark. It won two Academy Awards, and Gore won the 2007 Nobel Peace Prize for his efforts to communicate human-induced climate change.

An Inconvenient Truth (AIT for short) is the 11th-highest-grossing documentary in the United States. According to Texan climatologist Steve Quiring:

AIT has had a much greater impact on public opinion and public awareness of global climate change than any scientific paper or report.

But has the film achieved what it set out to do – raise public awareness and change people’s behaviour in order to reduce greenhouse gas emissions?

Measuring the film’s impact

A public survey by the Pew Research Center for People & the Press found that in the months following the documentary’s release, the percentage of Americans attributing global warming to human activity rose from 41% to 50%. But how do we know whether AIT contributed to this increase?

Several studies have experimentally tested the impact of viewing the film. A UK study found that showing selective clips from AIT resulted in participants feeling more empowered and more motivated to make lifestyle changes to fight climate change.

Similarly, surveys of moviegoers and students found that watching AIT increased knowledge about the causes of global warming and willingness to reduce greenhouse gases. However, this increased willingness didn’t necessarily translate into action. A follow-up survey conducted a month later found little change in behaviour.

One novel approach found a 50% increase in the purchase of voluntary carbon offsets in areas where AIT was shown. This is encouraging evidence that the film did lead to tangible behaviour change. But again, the effect wasn’t long-lasting. A year later, there was little difference in carbon offset purchases.

An analysis of drivers of public attitudes towards climate change found a significant relationship between media mentions of AIT and public perception of the urgency of climate change. In other words, the film produced a significant positive jump in the general public’s perceptions of the issue.

This study also found that polarisation decreased after the release of AIT, pouring cold water on the claim that Al Gore polarised the climate debate. Rather, the polarised positions on climate science among Democratic and Republican leaders (one party broadly accepting the science, the other significantly rejecting it) was found to be the key driver of public polarisation on climate change.

This led the study’s author, Robert Brulle, to state:

I think this should close down forever the idea that Al Gore caused the partisan polarisation over climate change.

This body of research underscores the difficulties confronting any public awareness campaign. AIT was successful in raising public awareness of climate change, increasing willingness to change behaviour and, in some cases, actually changing behaviour.

However, the effect didn’t last long. This indicates that persistent communication efforts are required to promote sustained behaviour change.

Scientists critique An Inconvenient Truth

While AIT was effective among the general public, there is no tougher crowd for a science documentary than scientists. A survey of members of the American Meteorological Society and the American Geophysical Union found that among the scientists who had seen and rated AIT, 72% said the film was either somewhat or very reliable.

To put this in perspective, only 12% of scientists who had read Michael Crichton’s contrarian novel State of Fear rated it as somewhat or very reliable.

Going into more detail, an edition of GeoJournal had four scientists critique the scientific accuracy of AIT. Unfortunately, the panel was made up of two mainstream scientists and two contrarian scientists – a false-balance form of coverage that actually causes confusion rather than increases literacy in the context of media coverage. (For an incisive look at false-balance coverage of climate change, watch John Oliver’s statistically representative climate change debate.)

A statistically significant climate change debate

The outcome is somewhat predictable, with mainstream scientists reporting a more positive assessment of the accuracy of AIT than the contrarian scientists. Nevertheless, a useful overview of the exercise is provided by Texan climatologist Gerald North, who concluded that while there were some inaccuracies in AIT, on the whole it represented mainstream scientific views on global warming.

Ultimately, the factual inaccuracies in AIT were deemed inconsequential and don’t undermine the main message of the film.

Inspiring others

While most of the research into the impact of AIT investigates the direct effect on viewers, a potentially more significant impact is the film’s role in inspiring others to follow Gore’s example in communicating the issue of climate change to others.

Personally, I can attest to this influence. Before 2006, I hadn’t given much thought to the climate change issue. Watching AIT raised a number of questions about the human role in global warming.

With the issue salient in my mind, I got into conversations with family members who happened to reject the scientific consensus on climate change. This precipitated the founding of Skeptical Science, which led to me becoming a researcher in climate communication at the University of Queensland.

I’ve spoken to or know of many other climate communicators whose awareness of the issue dawned with their viewing of AIT. While the direct effect of the original screening of the film may have dissipated, the impact of those inspired to communicate the realities of climate change persists.

For me, the film precipitated a series of events that ultimately redirected the course of my life. An Inconvenient Truth wasn’t just behaviour-changing, it was life-changing.

No lab experiment can quantify that level of impact.


1 0

Printable Version  |  Link to this page


Comments 1 to 10:

  1. If AIT sparked the birth of SkS, then by such outcome alone, it proved to be most valuable popular climate science doc ever conceived. All other reviews and critiques fade away in view of that simple event. Hopefully Al Gore reads that and can be proud of it.

    1 0
  2. AIT also created an interesting lightning rod for deniers.  My experience has been that many simply think they need to take out Al Gore and Michael Mann, and the whole problem simply goes away because 97% of climate scientists, in their view, aren't really sold on AGW.  Al Gore is after all the only "climate scientist" many people can name.

    0 0
  3. I've also seen the most quoted error in AIT is when Al Gore mentioned that most scientists think the Arctic will be ice free sometime after 2030.  However one scientist from the US Naval Academy said it could be as early as 2013.  Since this obviously didn't happen and I haven't heard Dr. Wieslaw Maslowski's views since about 2011 when he revised his prediction to 2016, many deniers stop there.  However the NSIDC report for Arctic Ice cover for today is rather eye opening in that the 2030+ group still looks well on track.

    0 0
  4. knaugle @3, by 'ice free' you mean 'ice free at the summer minimum' right? ... 2030 does seem a conservatively assured prediction for that to happen.

    0 0
  5. @4,

     You don't seem to understand the consequences of a so called ice-free arctic aka "THE BIG BLUE EVENT". It means the structural integrity given by the thicker multi-year sea ice is largely gone.

    This, in turn, means the thinner seasonal ice is easier and easier to break up making the arctic less able to deflect solar radiation from the earth making Greenland more liable to melting and, so, potentially shut down the thermohaline cycle that warms Europe.

    Where are the Syrians going to go then?

    This is real politik!!

    This is the negative externality of mixed market failure!!! Some even call it 'picking winners'...


     **[Go Greed: why did you have kids again?]

    0 0
  6. @4

    Actually, the Arctic Summer minimum is declining about 13% a decade according to the NSIDC reports.  At that rate, there should still be some ice cover during the Summer minimum into the 1940s.  However, this assumes there is not some tipping point at which this decline accelerates

    NSIDC 2015 Melt Season in Review

    Simply drawing the line, 50 years ago, the Summer Ice coverage was thought to be a minimum of about 4.3 million square miles, in recent years that has shrunk to less than 2 million square miles.  By 2030 I'd not be surprised to see that just a bit over 1.4 million square miles and with some years in the 750K range, others near 2 million.  That is getting painfully close to ice free.  From there we will be discussing how long ice free lasts, rather than whether or not as we are now.

    0 0
  7. Re @5

    Actually the value from the 1960s comes from the Cryosphere Today site, it's older data: Timeseries of annual and seasonal sea ice extent from 1901-2010, and not by drawing the line.

    Cryosphere Today

    0 0
  8. knaugle

    That would be this graph...

    Although some error margins on the earlier years estimates would be good. Those early years are coming from limited documentary sources.

    0 0
  9. Thanks Knaugle for clarification. I was just asking to be super clear on the @3 text so that a denialist couldn't undermine credibility and feed doubt. I am in strong agreement (as I said in @4) that we will be ice free at the summer minimum by ~2030 and agree, as you say, that by then (or shortly thereafter, certainly by 2040) we will instead be measuring the duration of being ice free. Thanks again!

    0 0
  10. chriskoz @1, I thought your comment was extremely profound. Yes, for SkS to be born out of AIT really does make the evolutionary legacy of AIT quite monumental. Thank you for highlighting this point.

    0 0

You need to be logged in to post a comment. Login via the left margin or if you're new, register here.

The Consensus Project Website


(free to republish)

© Copyright 2024 John Cook
Home | Translations | About Us | Privacy | Contact Us