A newly released study has found that mountaintop glacier ice in the tropics of all four hemispheres has diminished dramatically over the past 50 years. Among the findings of the study, published in the journal Global and Planetary Change, are that a glacier near Puncak Jaya, in Papua New Guinea, lost about 93% of its ice between 1980 and 2018. Between 1986 and 2019, the area covered by glaciers on top of Mt. Kilimanjaro in Africa decreased by nearly 75%.
The study combined NASA satellite imagery with data from ice cores drilled during field expeditions on tropical glaciers around the world. The combination of measurements demonstrated that climate change is causing these glaciers to disappear and that the ice loss has accelerated in recent years.
The study looked at glacier ice in Kilimanjaro in Tanzania, the Andes in Peru and Bolivia, the Tibetan Plateau and the Himalayas, and ice fields in Papua, New Guinea. Collecting ice cores from these places provides information on the climate in these regions over the centuries and millennia. As snow falls on a glacier each year, it is buried and compressed to form layers that preserve the chemistry of snow, pollutants from the atmosphere, and biological material such as plants and pollen.
Glaciers in the tropics respond more quickly to climate change because they exist in the warmest areas of the world and survive only at very high altitudes. For many of these tropical glaciers, it is too late to prevent their demise. It is not too late to attempt the slow down the buildup of greenhouse gases in the atmosphere that is causing the planet to warm, but we don’t have unlimited time to act.
Photo, posted February 12, 2009, courtesy of Christoph Strassler via Flickr.