“Unfortunately, we made the prediction. I wish we hadn’t,” says Douglas R. Hardy, a UMass geoscientist who was among 11 co-authors of the paper in the journal Science that sparked the pessimistic Kilimanjaro forecast. “None of us had much history working on that mountain, and we didn’t understand a lot of the complicated processes on the peak like we do now.”

“The glaciers are still shrinking, and in the next decades they will almost certainly disappear, but it will probably be on the order of three or four decades, maybe five,” Hardy said recently. “But we don’t know for sure. It might be in only two.”

No one contests that the glaciers have retreated. Photographs show they have shrunk in area by more than 80 percent since 1912. In fact, glaciers from the Alps to the Andes have retreated dramatically since 1900.

Thompson said that despite the recalibration of their prediction, the larger issue has to remain in sight.

“The real message here is that these ice fields will disappear. Whether it is in 10 years or 30 years is not the issue. The fact they will disappear within a few decades, as will many glaciers throughout the tropics, is the real concern,” he said.

“The opinions of global warming doubters will change on a dime depending on whether it is cold winter or a hot summer. The only opinion that matters is nature’s. Nature has a way of humbling us all. It still remains to be seen just who that will be” in the end, Thompson said.