For most of us in the west, the African mountain Kilimanjaro is known for two things: its summit is the point on the planet at which one can see more surface area of Earth than from any other location (the North American champ for that is Mount Diablo, which I can see from my back window); and, although it sits close to the equator, its summit is perpetually shrouded in snow, a fact immortalized by Ernest Hemingway's 1938 short story, The Snows of Kilimanjaro.
Make that, "was perpetually shrouded."
In 2000, images from Landsat, one of the various Earth-observing satellites, took an alarming picture, showing that much of the snow and glaciation at the Kilimanjaro summit had disappeared in just ten years. The 1990 and 2000 photos are shown to the right; click them for larger versions at NASA. At the time, scientists estimated that the remainder of the ice and snow would be gone by 2015.
They now have to revise their estimates. Recent photos (small version to the left, click for larger) show that very little of the mountain's snow remains; what's left will probably be gone in a just a few more years. Before the decade is out, Kilimanjaro will lose the snow which covered it for the last 11,000 years -- the snow which fascinated travelers, inspired artists, and gave it the name "shining mountain." Global warming and deforestation are both culprits; the relative balance between the two is still subject to debate (see comments for links). We've linked to other before/after images showing the effect of climate disruption, but there's something deeply symbolic about this particular example.
The 2004 image is part of a collection called NorthSouthEastWest: A 360° View of Climate Change, given to the attendees of this week's G8 energy and environment summit. The UK, which becomes the head of the G8 this year, has already stated that it will try to make climate disruption the top agenda item for the organization. Pictures like these are useful for making visceral the often-academic discussions of carbon and timelines, and for driving home the point that global warming isn't a problem off in the future, but is happening -- and having serious consequences -- right now.
Please be very careful about this... I have seen comments elsewhere that talk about a Nature article which attributes this melting to deforestation near this mountain.
Let's make sure the facts are straight or this will used as another example of environmental alarmism.
Good point. I'll look for that Nature piece, and will change the wording to something a bit more careful. Thanks.
Okay, here's what I found:
In 2002, Lonnie Thompson, et al, published an article in Science on Kilimanjaro ice core records. Thompson leans towards global warming as being the primary culprit in the disappearance of the mountain's ice and snow. Articles written about the Thompson piece include one in Nature News (*not* a full article in Nature):
...and one from the BBC:
Both focus on Thompson's work, but also give space to proponents of the theory that deforestation is the primary culprit. Nature talks to Euan Nesbit of the Royal Holloway University of London and to Douglas Hardy of U Mass Amherst. The BBC also talks to Hardy. Interestingly, Hardy is footnoted in Michael Crichton's State of Fear as dismissing the idea that global warming had anything to do with Kilimanjaro's ice retreat. Here's what Hardy had to say about that (from a Boston Globe article):
But UMass-Amherst climatologist Douglas Hardy, a coauthor of the 2004 paper on Kilimanjaro cited, says Crichton is distorting his work. Crichton is doing ''what I perceive the denialists always to do,'' says Hardy. ''And that is to take things out of context, or take elements of reality and twist them a little bit, or combine them with other elements of reality to support their desired outcome.''
For example, while the case of Kilimanjaro does seem more complicated (with factors like drier conditions and less cloud cover also implicated in its glacial retreat), Hardy notes that for other glaciers, especially in tropical latitudes, ''the link is very clear between changes in tropospheric temperature and [glacial retreats].'' And even in the case of Kilimanjaro, Hardy adds, climate change may be playing a role.
As for the notion that replanting the forest at Kilimanjaro's base will help the glacier to grow again, Hardy says: ''The forests need replanting for many reasons, but I think that [Crichton's] idea is preposterous, without some larger-scale changes.''
So it's safe to say that the idea that global warming is at least partially to blame is widely accepted, but that deforestation also contributed -- the balance of contribution remains a point of argument.
Getting people to admit that deforestation is to blame for something as dramatic as a mountain losing its snow is in itself a victory.
Ridiculing the notion that puny humans can be responsible for any sort of climate change is one of the denial crowd's favorite "sneering points."
Here are some more comments I found...
When Thompson's reports of glacial recession on Kilimanjaro first emerged in 2002, the story was quickly picked up and trumpeted as another example of humans destroying nature. It's easy to see why: Ice fields in the tropicsKilimanjaro lies about 220 miles (350 kilometers) south of the Equatorare particularly susceptible to climate change, and even the slightest temperature fluctuation can have devastating effects.
"There's a tendency for people to take this temperature increase and draw quick conclusions, which is a mistake," said Douglas R. Hardy, a climatologist at the University of Massachusetts in Amherst, who monitored Kilimanjaro's glaciers from mountaintop weather stations since 2000. "The real explanations are much more complex. Global warming plays a part, but a variety of factors are really involved."
According to Hardy, forest reduction in the areas surrounding Kilimanjaro, and not global warming, might be the strongest human influence on glacial recession. "Clearing for agriculture and forest firesoften caused by honey collectors trying to smoke bees out of their hiveshave greatly reduced the surrounding forests," he says. The loss of foliage causes less moisture to be pumped into the atmosphere, leading to reduced cloud cover and precipitation and increased solar radiation and glacial evaporation.
Evidence of glacial recession on Kilimanjaro is often dated from 1912, but most scientists believe tropical glaciers began receding as early as the 1850s. Stefan L. Hastenrath, a professor of atmospheric studies at the University of Wisconsin, Madison, has found clues in local reports of a dramatic drop in East African lake levels after 1880. Lake evaporation indicates a decrease in precipitation and cloudiness around Kilimanjaro.
"Less cloud coverage lets more sunlight filter through and hit the glaciers," Hastenrath said. "That increase in sunlight then provides more energy for evaporation of the glacier."
Hastenrath found further evidence in sailing expedition reports from the same period. "Ships along the East African coast recorded very fast equatorial winds around 1880," he said. "Just like today, swift westerlies are always linked with drier seasons in East Africa, so it's very likely Kilimanjaro had a dry period around this time."
Along with a higher risk of evaporation, a drop in precipitation also makes for a dark glacial surface, made up of old, dirty snow. A darker glacial surface absorbs more solar radiation than fresh, white snow (like a blacktop playground baking in the sun).
Global warming began to take effect in East Africa by the early 20th century.
"The warming increases humidity, and as the air gets more moist, it hinders evaporation," Hastenrath explained. "The energy saved from evaporation is instead spent on melting. That might seem like a good thingto stop evaporation of the glaciersbut it's certainly not. Melting is eight times more energy-efficient than evaporation, so now, with global warming, the glaciers are disappearing eight times faster than before."
All of the previous comment is a quote from the cited article. I need to figure out how to use Italics or blockquote.
Please see this post at Organic Matter. (http://www.organicmatter.net/node/47)
While the paper in Science and some other sources do suggest global warming is the principal culprit, others suggest that solar radiation and deforestation are the bigger factors. Global warming is undoubtedly involved, but, like the glacial lakes in the Arctic (see recent Science News piece about geologists tracking diatoms on the floors of these lakes), the initial recession of Kilimanjaro's ice-cap can be dated back to at least the beginning of the industrial revolution, if not before.
Given the current political climate (no pun intended), we must be vigilant about picking our words carefully, ensuring all of us have the facts. Yes, Kilimanjaro can be used as an example of our current changing climate. Should we cite it as an example of our poor stewardship? Yes, but let's not focus on it or include it in our Top Ten List of sh*tty thing happening because of global warming.