Melting snows on Mt. Kilimanjaro are not evidence of global warming.

October 13, 2007

Return to Critique of “An Inconvenient Truth” 

What is the extent of Al Gore’s argument that Mount Kilimanjaro, in Tanzania, is an indicator of the effects of global warming? In his book he simple shows a series of three pictures: one taken in 1970, one taken in 2000, and one taken in 2005. The two pictures from 1970 and 2000 are taken from the same angle and thus allow the reader to see a large change in the glacial cover. The entire text consists of 109 words and can be seen in my reproductions of pages 42 through 45 in figures 1 and 2 below.

Figure 1. Reproductions of pages 42 and 43 of An Inconvenient Truth. I have “photoshopped” the images from these pages to make the snow and glaciers stand out more clearly. The obvious point that the reader is supposed to be impressed with is the dramatic decline in snow and glaciers on Kilimanjaro between 1970 and 2000.

Figure 2. Reproductions of pages 44 and 45 of An Inconvenient Truth. I have “photoshopped” the images from these pages to make the snow and glaciers stand out more clearly. The reader is supposed to note the further decline in the glaciers up to 2005. But note that the picture is taken form a different angle than those on pages 42 and 43.

In the movie version of An Inconvenient Truth these same pictures are shown with Al Gore speaking over them saying essentially the same thing seen in the text of the above images. That’s all there is. There are no references to any scientific studies done concerning these glaciers and the possible causes for their retreats. We are simply shown these compelling photographs and the clear impression is left that this shrinkage is caused by CO2 induced global warming.

What does the best science say concerning the glaciers on Kilimanjaro?

Georg Kaser (Tropical Glaciology Group, Department of Geography, University of Innsbruck). et. al., concluded in the International Journal of Climatology in 2004 that since the end of the ice age Kilimanjaro’s glacial extensions and recessions reached their maximum in the Little Ice Age. That is, the glaciers on Kilimanjaro were smaller one or two or three thousand years ago than they were 150 years ago. Then around 1880, long before the atmospheric CO2 concentration showed a significant increase, a climate shift caused them to start receding from their Little Ice Age maximum. On page 336 of the journal article they said that temperature increases “have not contributed to the recession process on the summit so far.”

Philip Mote (Department of Atmospheric Sciences, University of Washington Climate Impacts Group) et. al. said in a recent article in American Scientist, “The observations … point to a combination of factors other than warming air—chiefly a drying of the surrounding air that reduced accumulation and increased ablation—as responsible for the decline of the ice on Kilimanjaro since the first observations in the 1880s.” They continue, “If human-induced global warming has played any role in the shrinkage of Kilimanjaro’s ice, it could only have joined the game quite late, after the result was already clearly decided, acting at most as an accessory…”

Thomas Molg (Innsbruck University Network of Climate and Cryospheric Research) and Douglas Hardy (Climate System Research Center, Department of Geosciences, University of Massachusetts) pointed out in the Journal of Geophysical Research that “it has been speculated that general global warming is directly driving the retreat of Kilimanjaro’s glaciers [e.g., Irion, 2001]. However, detailed analyses of glacier retreat in the global tropics uniformly reveal that changes in climate variables related to air humidity prevail in controlling the modern retreat…”

Gore refers to his “friend, Dr. Lonnie Thompson” and said “He predicts that within 10 years there will be no more ‘Snows of Kilimanjaro.’” But Thompson’s paper Kilimanjaro Ice Core Records: Evidence of Holocene Climate Change in Tropical Africa in the journal Science in 2002 is clearly not a ringing endorsement for Gore’s claim that the recession of Kilimanjaro’s glaciers is due to anthropogenic CO2. In fact, nowhere in the article is the term “CO2″ ever mentioned. Thompson acquired and studied six ice cores from the oldest glaciers near the summit. In the Northern Ice Field (NIF), which supplied the oldest three ice cores (NIF1, NIF2, and NIF3), only one of the cores (NIF3) indicates that its position was covered with ice at the end of the ice age. Thompson’s analysis of the ice core data “suggests that, at ~4 ka [4 thousand years ago], the NIF was smaller than it is today and that the crater-side ice wall likely retreated past the present-day sites of NIF1 and NIF2.” (emphasis added by Moriarty).

Thompsom provides abundant evidence that the climate in tropical Africa has undergone huge and rapid changes multiple times since the end of the ice age (12,000 years ago). For example, 11,000 to 4,000 years ago lakes in the area were up to 100 meters higher than today. Lake Chad in sub-Saharan Africa expanded “from 17,000 km2 to cover an area between 330,000 and 438,000 km2, comparable to that of the Caspian Sea today.” Then it receded back to its present size (17,000 km2) 4,000 years ago when “conditions became cooler and drier.” In fact Thompson states “The Kilimanjaro record documents three abrupt climate changes in this region: at 8.3, 5.2, and 4 ka.” (“ka” means “thousand years ago”).

It is true that Thompson says “if climatological conditions of the past 88 years continue, the ice on Kilimanjaro will likely disappear between 2015 and 2020.” But nowhere in this paper does he even attempt to link the principle drivers of this ice loss to anthropogenic CO2.

Brief look at CO2, temperature and ice extent at Kilimanjaro

Figure 3. Atmospheric CO2 concentration vs. Kilimanjaro ice extent. CO2 data up to 1953 is from the Siple ice core. CO2 data after 1953 is from Mauna Loa, Hawaii. Ice extent for 1880 is from Osmaston, H. 1989. Glaciers, glaciation and equilibrium line altitudes on Kilimanjaro. In Quaternary and Environmental Research on East African Mountains, ed. W. C. Mahaney. Rotterdam: Brookfield, pp. 7-30. Ice extent from 1912 to present is from “Kilimanjaro Glaciers: Recent areal extent from satellite data and new interpretation of observed 20th century retreat rates” Cullen, et. al., GRL 33, 2006

Figure 4. Kilimanjaro summit temperature and ice extent. Ice extent data is the same as figure 3 and the temperature dat is from the National Centers for Environmental Prediction/National Center for Atmospheric Research; compiled by Doug Hardy, University of Massachusetts, Amherst. I have digitized the data from a graph adapted by Tom Dunne.

Return to Critique of “An Inconvenient Truth” 


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  1. Well done. Interesting facts that all need to know.
    Thanks for sharing.

  2. What I cannot find is a series of photos taken from the same spot AND at the same time of year. Surely some months are colder and wetter and would therefore show more snow. I could take photos of the Alps or Rockies in July and compare them to photos taken in January and prove that there is less snow and therefor rising temperatures!

    • I think he would have taken the seasons into consideration when taking the photos.

  3. I absolutely get sick whenever I see the documentary, An Inconvenient Truth. He is so desperate to prove himself right and his graphs and information are not even sufficient. And to top it all off, whenever he introduced himself, he said, “Hello, my name is Al Gore, the former President of the United States”, and that just digs into my skin even more. Al Gore’s information is “supported by numerous scientists”, but I have never heard a name of one of his so called scientists. I think that Al Gore’s documentary should be banned in the United States and around the whole globe from being viewed by young children who could very well buy into the stupid lies that Al Gore is telling, and yes I am calling his words stupid. Global warming is all a hoax anyway and our planet is not in danger and we are not going to all die by being burnt to a crisp because Jesus Christ is monitoring earth and only He Himself governs what happens to earth. Amen!?

    • Gore cites his sources clearly in his book, and if you’d taken the time to read it, you would know that. None of his information is blatantly untrue, in fact the only reason any of his information has been contested is that data simply hasn’t been taken over a long enough time span. He is in no way corrupting our youth. The one thing you have shown knowledge of is the common Christian back up- “When in doubt, credit Jesus.” Please think more.

      • Molly,

        It must be you who has not read the book. I have his book at the desk where I sit this very moment. It is unabridged. Let me make this perfectly clear to all my readers: “An Inconvenient Truth” does not site any sources. There are no footnotes. There are not lists of references at the end of each chapter. There is no list of references at the end of the book. There are not superscripts in the text that align to references. THERE ARE NONE.

        Molly, If you ever read a typical scientific journal article you would find there are typically a dozen references for each page of text. These references show the source (usually a journal), the name of the article, the date and volume, etc. These are the things that are required to crosscheck his claims. There are simply none for “An Inconvenient Truth.” NONE. There are only credits for the photos.

        Any readers who are in doubt about this can simply go to your local library or book store and check for yourself.

    • Hi Micheal,
      I just watched the film for the first time. I have not read the book. Gore’s position and delivery is certainly compelling and emotional. I led myself to this site to get a more balanced picture of the Global Warming “debate.” And though I have made no hard conclusions, I feel like it is in best interest of human kind to head in a direction where upkeep of our planet is on the forefront of our minds. It actually saddens me that people have to be confronted with such catastrophic scenarios to feel compelled to give a bleep about or planet. Blah blah blah, my weak sentiments probably have no effect on those who are blind to the perils of spending so much time caged up in a ceilinged structure. THE REAL POINT I wanted to make is to Micheal: I am glad to see you are not blindly swayed by the emotional credence of Gore’s position. It seems you carefully approached his material with healthy skepticism. My question to you is- why haven’t you examined your faith in this way?

  4. Dear Michael Spence,

    Thank you for your comment.

    I would never even consider “banning” Gore’s movie or books. They must be countered with reasoned arguments – even if it is tedious and boring to do so.

    One of the telling things about Gore’s “An Inconvenient Truth” is that the book has absolutely no references, other than credits for the photos. Am I the only one who has noticed this? I consider it to be “comic book science.”

    Also, I have serious doubts that “Jesus Christ is monitoring the earth and only He Himself governs what happens to earth.” This is saying that human beings have no free will.

    best regards

  5. “Climate scientists have long maintained — and evidence from the real world is already confirming — that warming doesn’t just result in higher temperatures. It also leads to changes in weather patterns, including more intense precipitation in some areas, more severe droughts in others (and sometimes, as in the case of the American Southeast, a little of both). And that may well be what’s happening at Kilimanjaro. While strongly disputing Thompson’s explanation, Georg Kaser of the Institut für Geographie in Innsbruck, Austria, writes that “we are confident that global warming is the ultimate driver of glacier shrinkage on Kilimanjaro due to the strong relation between Indian Ocean dynamics and East African precipitation.””


    • Dear Are-Harold Brenne,

      Thank you for the comment.

      It is interesting that you would mention Georg Kaser.

      In the Miami Herald Kaser said “According to our understanding, the Kibo glaciers shrink and will disappear not because of changing climate conditions but because of conditions that are unfavorable in principle: It is simply too dry for these glaciers to exist under normal Holocene conditions”

      He points out that most of the glacier is less than two centuries old saying “there are indications that a series of exceptional wet years allowed them to build up during the first half of the 19th century.”

      What does he mean when he says that the Holocene “is simply too dry for these glacier to exist?” Please read about the megalakes that existed in the Sahara during the earlier Holocene and are now gone. They did not disappear because of anthropogenic global warming. This is part of the same natural pattern that is reducing the glaciers on Kilimanjaro.

      Best regards,

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