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Mt. Kilimanjaro's ice loss is due to land use

The skeptic argument...

Mt. Kilimanjaro's ice loss is due to land use

'Gore claims the snowcap atop Africa's Mt. Kilimanjaro is shrinking and that global warming is to blame. Yet according to the November 2003 issue of Nature magazine, "Although it's tempting to blame the ice loss on global warming, researchers think deforestation of the mountain's foothills is the more likely culprit. Without the forests' humidity, previously moisture-laden winds blew dry. No longer replenished with water, the ice is evaporating in the strong equatorial sunshine."' (James Taylor)

What the science says...

Mount Kilimanjaro's shrinking glacier is complicated and not due to just global warming. However, this does not mean the Earth is not warming. There is ample evidence that Earth's average temperature has increased in the past 100 years and the decline of mid- and high-latitude glaciers is a major piece of evidence.

Indeed deforestation seems to be causing Mount Kilimanjaro's shrinking glacier so Gore got this wrong. But Philip Mote, author of the study in Nature, puts it in perspective: "The fact that the loss of ice on Mount Kilimanjaro cannot be used as proof of global warming does not mean that the Earth is not warming. There is ample and conclusive evidence that Earth's average temperature has increased in the past 100 years, and the decline of mid- and high-latitude glaciers is a major piece of evidence."

Printable Version  |  Link to this page

Further reading

Raymond Pierrehumbert has written a lengthy and informative article Tropical Glacier Retreat that explains the physics of tropical glaciers and the complexities of Mt Kilimanjaro.

Comments

Comments 1 to 4:

  1. To say that climate change is definitely not even partially responsible for the loss of glacier ice mass on Kilimanjaro is an inaccurate misrepresentation of the science. As Raymond Pierrehumbert's article that you linked to made clear, it is likely to be at least partially responsible.

    Furthermore, Gore did not "get it wrong" as you claim - in the movie, the retreat of Kilimanjaro is not claimed to be purely due to global warming , but it is given as an example of the sort of thing one can expect in a warmer world, and it is quite true that loss of major glaciers is something we can expect.

    I also think you ought to link to the global glacier mass balance graph at on the National Snow and Ice Data Center (NDIS) graph here, from which one can see that the worldwide trend is sharply downwards; and there is no dispute in the peer reviewed literature that this is mostly due to climate change. Admittedly, Gore could and should have chosen a better example than Kilimanjaro, such as the Andean glaciers, but he didn't "get it wrong", he just illustrated a valid and accurate point with a poorly-chosen illustration.

    Finally, I think you should point out that hundreds of millions of people (and huge ecosystems) rely for their water on the annual glacier summer melts that in many cases may cease during the next 50-100 years, as mountain glaciers start to disappear. This includes a large proportion of China's population, all of the “Stans” (Pakistan, Uzbekistan, Turkmenistan, etc.) and most of the Andean countries in South America (e.g. see here , here and here).
    Response: Dave, all good points and I confess updating the Mt Kiliminjaro page is high up on my to-do list. Thanks for the link suggestions (I do link to the NSIDC graph elsewhere but here is a good place also) - will attend to this shortly as soon as time permits.
  2. Okay thanks. Some more relevant links:

    1) Alps Glaciers Gone by 2050, National Geographic News.

    2) Mountain Glaciers Melting Faster Than Ever, National Geographic News, which includes the following:
    Lonnie Thompson, an expert in ancient climates at Ohio State University ... said ... "Kilimanjaro's glaciers are melting so quickly ... that the mountain lost nearly a quarter of its ice from 2000 to 2006 ... [it points out that melting is accelarating everywhere and adds] ... If you look at what's happened to these glaciers, they're not just retreating, they're accelerating [their retreat]," he said. "And it raises the question of whether this might be a fingerprint of [human-caused global] warming.


    In other words, even if the melting of Kilimanjaro prior to 2000 contains 0% influence from climate change (which is unlikely), the influence of climate change on the melt rate of Kilimanjaro since 2000 is almost certainly well above 0%. No other factor, including deforestation, can credibly account for the sudden acceleration post-2000.


    3) Himalayan glaciers 'melting fast', BBC:
    "Melting glaciers in the Himalayas could lead to water shortages for hundreds of millions of people"

    Admittedly this article has the disadvantage that it quotes a WWF study - it would be nice to find a similar one that was independent of any lobby group. But it's mainstream stuff and worth quoting if you can't find a better one on the Himalayas' glacier melt and the likely effect of this on neighbouring countries.

    4) China glaciers melting at alarming rate, Chinese National Coordination Committee on Climate Change.
  3. I've found a better link re. the Himalayas:
    Himalaya Ice-Melt Threat Monitored in Nepal, National Geographic News, which includes the following:
    For example, researchers at the National Institute of Hydrology in Roorkee, India, estimate that reduced glacier meltwater would cut July-through-September river flow of the Ganges by two-thirds.

    This decline would leave 500 million people and 37 percent of India's irrigated land short of water.

    Himalayan glaciers also feed six other of Asia's great rivers—Indus, Brahmaputra, Salween, Mekong, Yangtze, and Huang Ho—putting communities across this region at risk of water shortages.
  4. I think it's worth pointing out that Kilimanjaro has never held much water in it's glaciers and that summer melting has never been a source of water for the people below unlike in other areas.

    Interestingly enough, there seems to be some suggestions, within the scientific community, that increased precipitation, caused by global warning, may actually increase the amount of ice on Kilimanjaro and save the glacier.

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