Kilimanjaro’s ice fields didn’t disappear by 2020. That doesn’t mean climate change isn’t happening

Perhaps due to its global renown, Kilimanjaro has long been at the center of climate research — and disagreements about the impact of climate change.

In the 2006 documentary "An Inconvenient Truth," former Vice President Al Gore used Kilimanjaro, Africa’s tallest mountain, to demonstrate the effects of climate change on its glaciers, showing a series of photos of the mountain, each appearing to show less and less ice and snow cover over time. 

"Within the decade, there will be no more snows of Kilimanjaro," Gore warned.

More than a decade later, Gore’s claim has become the focus of climate change skeptics who note that some of scientists’ dire predictions aren’t coming true.

"Let’s see what days of the week it’s snowing," said a Facebook user in one Jan. 26 video, showing an eight-day Kilimanjaro forecast that called for snow on five days. "Obviously, Al Gore’s point there that there will be no more snow on Kilimanjaro in a decade is laughably false."

Gore’s claim, with its clumsy allusion to an Ernest Hemingway short story, was not about the daily weather forecasts so much as what would happen to the ice fields that have been there for centuries. 

His comments can be traced back to a 2002 prediction by scientists who wrote: "Over the 20th century, the (area) of Kilimanjaro’s ice fields has decreased 80%, and if current climatological conditions persist, the remaining ice fields are likely to disappear between 2015 and 2020."

But it’s now 2022, and Kilimanjaro’s glaciers haven’t fully disappeared. Does that mean climate change isn’t happening, as some skeptics suggest? 

No, scientists say. It’s important to look at the limitations of the data that went into the prediction, they say, as well as the other substantial evidence of the impact of climate change, on Kilimanjaro and elsewhere.

The 2002 prediction was made by extrapolating from available data on ice on Kilimanjaro, explained Douglas Hardy, a co-author of the 2002 paper. The researchers relied on existing estimates of the size of the ice fields in 1912, 1953, 1976 and 1989, and on aerial photographs taken during their February 2000 trip to Kilimanjaro.

Hardy, an adjunct professor at the University of Massachusetts Amherst, said that the prediction was made with an important caveat: "if climatological conditions of the past 88 years continue." Those climatological conditions didn’t persist, he said, meaning the glaciers didn’t diminish as quickly as predicted.

In hindsight, Hardy said, the prediction should have more clearly articulated additional caveats, including:

• Accounting for the potential pitfalls of prior research. The existing data used to estimate glacier loss over time had limitations, such as its age and the poor resolution of satellite imagery.

• Avoiding overgeneralizing. Kilimanjaro had a few separate ice fields in 2000. Saying that some bodies of ice would disappear before others would have been more precise.

• Emphasizing the role of yearly variations. Research suggests that variability in precipitation from year to year significantly impacts glacier health on Kilimanjaro in particular. A given year’s snowfall amounts, for example, would likely influence how fast glaciers receded.

Of the roughly 6 meters of ice Kilimanjaro’s glaciers have lost in the past 22 years, Hardy added, 1 meter disappeared between 2000 and 2001, which bolstered researchers’ beliefs about the rate of ice loss.

Since Kilimanjaro’s ice didn’t completely disappear as predicted by 2020, it has become fuel for those who believe climate change is a hoax.

Websites such as Climate Realism and The Climate Record and anti-regulation groups have pointed to Kilimanjaro’s remaining snow and ice to undercut climate science and Gore as an environmental activist. The Facebook video was produced by the Hartland Institute, which runs the Climate Realism site. 

Experts described such arguments as disingenuous and in bad faith.

According to Hardy, most of Kilimanjaro’s ice fields have disappeared. Based on published literature and more than 20 years of observations, measurements and monitoring of available imagery, he said, by and large, only the mountain’s northern ice field remains, now about half a square kilometer in size.

"The trends in ice loss on Kilimanjaro are clear," said Jason Smerdon, a Columbia University professor who studies climate change. He encouraged people to look beyond the predicted time frame and acknowledge that the glaciers are ultimately disappearing as the paper indicated. 

M Jackson, a glaciologist and author of "The Secret Lives of Glaciers," said the lesson from the missed prediction is that the science needs to be refined and built upon.

"I think anybody in the glaciological sciences would be able to look at that and say, ‘that’s a prediction,’" she said. "If that does not come to pass, my natural inclination is not to invalidate the entire field of that science … but rather to say, ‘Hmm, what variables did I not get?’"

Philip Mote, a professor at Oregon State University, said many climate predictions such as those for global average temperature have been "remarkably close."

"You don’t see skeptics conceding that major success," he said. 

Indeed, the reality often turns out worse than climate models predicted, Mote said, noting that predictions about the depletion of the ozone failed to anticipate the hole that developed, and that Arctic sea-ice loss has occurred faster than forecasted.

Kilimanjaro ice fields don’t tell the full story of climate change, experts said. 

"Kilimanjaro, specifically, is not a temperature story," said Smerdon. "It’s actually declining because of reduced precipitation in East Africa that’s tied to warming temperatures in the Indian Ocean."

Plenty of other glaciers show more direct influence of climate change. Warming air and water temperatures are contributing to glacier loss in Greenland, for example. Similarly, the United Nations body that assesses climate science reported that glacier mass loss globally and declines in Arctic sea ice were attributed to rising surface air temperatures.

"The absolute huge overwhelming majority of glaciers are all receding in response to climate change," Hardy said. "But why look only at glaciers when we’ve got changes in ice cover on lakes, and we’ve got changes in the distribution of plants and animals?"

"A good scientist, a good citizen will consider all of the evidence before coming to conclusions," Hardy said.